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Bibliography on: Invasive Species

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ESP: PubMed Auto Bibliography 24 Sep 2018 at 01:33 Created: 

Invasive Species

Standard Definition: Invasive species are plants, animals, or pathogens that are non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause harm. Although that definition allows a logical possibility that some species might be non-native and harmless, most of time it seems that invasive species and really bad critter (or weed) that should be eradicated are seen as equivalent phrases. But, there is a big conceptual problem with that notion: every species in every ecosystem started out in that ecosystem as an invader. If there were no invasive species, all of Hawaii would be nothing but bare volcanic rock. Without an invasion of species onto land, there would be no terrestrial ecosystems at all. For the entire history of life on Earth, the biosphere has responded to perturbation and to opportunity with evolutionary innovation and with physical movement. While one may raise economic or aesthetic arguments against invasive species, it is impossible to make such an argument on scientific grounds. Species movement — the occurrence of invasive species — is the way the biosphere responds to perturbation. One might even argue that species movement is the primary, short-term "healing" mechanism employed by the biosphere to respond to perturbation — to "damage." As with any healing process, the short-term effect may be aesthetically unappealing (who thinks scabs are appealing?), but the long-term effects can be glorious.

Created with PubMed® Query: "invasive species" OR "invasion biology" OR "alien species" OR "introduced species" NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

RevDate: 2018-09-23

Wood JP, Beer SD, Campbell TS, et al (2018)

Insights into the introduction history and population genetic dynamics of the Argentine black-and-white tegu (Salvator merianae) in Florida.

Genetica pii:10.1007/s10709-018-0040-0 [Epub ahead of print].

Invasive species are a major threat to global biodiversity. The US state of Florida is especially susceptible to the spread of exotic reptiles due to its subtropical climate, disturbed habitats, and robust pet trade. The Argentine black-and-white tegu (Salvator merianae) is a large, omnivorous lizard currently established in two different regions of Southern Florida. These two populations pose potential threats to sensitive ground nesting species such as gopher tortoises, American crocodiles, and migratory birds. At present, the introduction histories of these populations and the degree to which they are connected by gene flow are largely unknown. To address these issues, we genotyped S. merianae from Hillsborough and Miami-Dade Counties at ten microsatellite loci to assess intrapopulation genetic diversity, the degree of gene flow between populations, and compare the plausibilities of several potential introduction scenarios. Our results indicate that both populations have low genetic diversity [mean number of effective alleles across loci in both populations = 2.09 and are highly differentiated from each other (GST = 0.170; G″ST = 0.545)]. In addition, our results suggest that these populations underwent a bottleneck event prior to their divergence. We discuss what our results suggest about the histories of Florida's invasive tegu populations, as well as how they inform ongoing management strategies.

RevDate: 2018-09-22

Mostert E, Gaertner M, Holmes PM, et al (2018)

A multi-criterion approach for prioritizing areas in urban ecosystems for active restoration following invasive plant control.

Environmental management pii:10.1007/s00267-018-1103-9 [Epub ahead of print].

Resources for biodiversity conservation and invasive plant management are limited, and restoring invaded vegetation is labour-intensive and expensive. Managers must prioritize their actions to achieve their goals efficiently and effectively. They must distinguish between areas that require only the removal of invasive alien plants ("passive restoration") from those that require additional restoration measures ("active restoration"). This study used a multi-criterion approach (Analytical Hierarchical Process) to develop a framework for identifying areas that require active restoration, and then to prioritize these areas for active restoration. The South African city of Cape Town is used as a test case to illustrate the utility of the framework. Framework criteria selected in determining the need for active restoration included: dominant alien species invading the area, density of invasion, duration of invasion, indigenous vegetation cover, adjacent land use, level of disturbance, size of the area, aspect, soil texture, soil depth and erodibility, slope and vegetation type. In deciding which areas to prioritize for active restoration, factors such as vegetation conservation status, selection in a regional conservation plan and connectivity function were assessed. Importance in ecosystem functioning (by providing a diversity of habitats and soil conservation) and the delivery of ecosystem service benefits were also considered. The resulting framework provides an objective tool for prioritizing sites for active restoration.

RevDate: 2018-09-22

Bernard J, Ewing CP, RH Messing (2018)

The Structure and Phenology of Non-Native Scolytine Beetle Communities in Coffee Plantations on Kaua'i.

Insects, 9(4): pii:insects9040123.

Populations and communities are known to respond to abiotic conditions, but the forces determining the distribution of particular insect pests are sometimes overlooked in the process of developing control methods. Bark and ambrosia beetles (Curculionidae: Scolytinae) are important pests of crops, forestry, and ecosystems worldwide, yet the factors that influence their success are unknown for many species. The Hawaiian archipelago is host to over three dozen invasive scolytines, many of which occur on Kaua'i and are pests of agriculture. We analyzed scolytine community dynamics at two coffee estates: a hand-harvested site in a tropical wet forest and a mechanically harvested site in a tropical dry savanna. Our regression analyses show overall scolytine abundance was negatively correlated with rainfall, as were four species: the tropical nut borer (Hypothenemus obscurus), H. brunneus, Cryphalus longipilus, and Xyleborinus andrewesi. These relationships contributed to the compositions of the communities being markedly dissimilar despite having the same species richness. Multivariate analysis found no influence from temperature or harvest method on community dynamics. This information can be valuable for the timing of pest control methods, for predicting the success of possible new scolytine arrivals on Kaua'i, and for forecasting how these species may spread with climate change.

RevDate: 2018-09-21

Rebelo AJ, Somers B, Esler KJ, et al (2018)

Plant functional trait data and reflectance spectra for 22 palmiet wetland species.

Data in brief, 20:1209-1219 pii:S2352-3409(18)30965-X.

We provide reflectance spectra for 22 South African palmiet wetland species collected in spring 2015 from three wetlands throughout the Cape Floristic Region. In addition, we provide summarized plant functional trait data, as well as supporting and meta-data. Reflectance spectra were collected with a portable ASD Fieldspec Pro using standard methods. The 14 plant functional traits were measured on 10 replicates of each species, following standard protocols. We provide tables detailing these standard methods, as well a table with hypotheses on how these 14 continuous traits, as well as an additional 9 categorical traits, may affect ecosystem service provision. In addition, tables are attached which detail which functional and spectral groups these species belong to, according to the data. Finally, we include a photographic plate of the species data are provide for. We make these data available in an effort to assist in research on the understanding of how traits affect ecosystem service provision in wetlands, and particularly of whether remote sensing can be used to map these traits in wetlands.

RevDate: 2018-09-21

Polidori C, Nucifora M, D Sánchez-Fernández (2018)

Environmental niche unfilling but limited options for range expansion by active dispersion in an alien cavity-nesting wasp.

BMC ecology, 18(1):36 pii:10.1186/s12898-018-0193-9.

BACKGROUND: Predicting the patterns of range expansion of alien species is central to develop effective strategies for managing potential biological invasions. Here, we present a study on the potential distribution of the American cavity-nesting, Orthoptera-hunting and solitary wasp, Isodontia mexicana (Hymenoptera: Sphecidae), which was first detected as alien species in France in 1960 and now is present in many European countries. After having updated its current distribution, we estimated the environmental space (based on bioclimatic data and altitude) occupied by the species and subsequently predicted its environmental potential distribution under both present and future climatic conditions at global scale.

RESULTS: The wasp lives in low-altitude areas of the Northern hemisphere with moderate temperatures and precipitation. The environmental space occupied in the invaded area is practically just a subset (42%) of that occupied in the native area, showing a process of environmental niche unfilling (i.e. the species only partially fills its environmental niche in the invaded range). Besides, I. mexicana could also live in other temperate areas, mainly in the Southern hemisphere, particularly close to the coasts. However, geographic (oceans) and/or climatic (tropical areas, mountain chains) barriers would prevent the species to reach these potential areas unless through human trade activity. The species could thus only reach, by active dispersion, the remaining invadable areas of Europe. Estimations for the future (2050 and 2070) predict an expansion through active dispersion towards North in the native range and towards North and East in the invaded range, but future conditions would not break down the current climatic barriers in the Southern hemisphere.

CONCLUSIONS: Isodontia mexicana has not shifted its environmental niche in the invaded area. It could still occupy some new areas by active dispersion, but confined to Europe. The conspicuous niche unfilling shown by this wasp species could reflect the likely single introduction in Europe just a few decades ago. Furthermore, results stay in line with other studies that found niche unfilling rather than niche expansion in insects.

RevDate: 2018-09-21
CmpDate: 2018-09-21

Anonymous (2018)

Stephanie Thomas: Modeling Disease Transmission in a Changing World.

Trends in parasitology, 34(3):173-174.

RevDate: 2018-09-20

Michelan TS, Thomaz SM, Bando FM, et al (2018)

Competitive Effects Hinder the Recolonization of Native Species in Environments Densely Occupied by One Invasive Exotic Species.

Frontiers in plant science, 9:1261.

The responses of native plants to competition with invasive plants depend mainly on the density of the invasive plants and on the ability of the native plants to compete for resources. In this study, we tested the influence of the invasive exotic Urochloa arrecta (Poaceae) on the early colonization of two native species (Pontederia cordata and Leersia hexandra) of aquatic macrophytes. Our hypotheses were (i) the competitive effects of U. arrecta on the native species P. cordata and L. hexandra are density-dependent and that (ii) these species respond differently to competitive interactions with the invasive species. We conducted the experiments in a greenhouse and in the field, in a tropical reservoir. The biomass of U. arrecta (ranging from 206.2 to 447.1 g) was manipulated in the greenhouse in trays with different densities. After the establishment of the invasive species, we added P. cordata and L. hexandra propagules to each tray. In the field, a propagule of P. cordata was planted in 36 sites with different densities of U. arrecta. The biomass and length of the natives and the biomass of the invasive species were measured in the greenhouse and in the field experiments. The biomass and length of the native plants decreased with increasing biomass of the exotic species in both experiments, showing that the competition between U. arrecta and native species depends on the density of the exotic species. The root:shoot ratio of L. hexandra decreased with increasing U. arrecta biomass, but the opposite occurred for P. cordata. These results indicate that native species exhibit different strategies of biomass allocation when interacting with U. arrecta. The strong competitive effects of U. arrecta and the different responses of the native species help to explain the reduced diversity of native macrophytes observed in sites colonized by U. arrecta. The results also suggest that in a scenario of dominance of exotic species, recolonization by native macrophytes is unlike to occur naturally and without human interventions that reduce the biomass of the exotic species.

RevDate: 2018-09-20

Chaisiri K, Dusitsittipon S, Panitvong N, et al (2018)

Distribution of the newly invasive New Guinea flatworm Platydemus manokwari (Platyhelminthes: Geoplanidae) in Thailand and its potential role as a paratenic host carrying Angiostrongylus malaysiensis larvae.

Journal of helminthology pii:S0022149X18000834 [Epub ahead of print].

Invasive species constitute one of the most serious threats to biodiversity and ecosystems, and they potentially cause economic problems and impact human health. The globally invasive New Guinea flatworm, Platydemus manokwari (Platyhelminthes: Geoplanidae), has been identified as a threat to terrestrial biodiversity, particularly soil-dwelling native species (e.g. molluscs, annelids and other land planarians), and is listed among 100 of the world's worst invasive alien species. We report here, for the first time, P. manokwari occurrences in many locations throughout Thailand, using voluntary digital public participation from the social network portals associated with the Thailand Biodiversity Conservation Group and collections of living flatworm specimens. Mitochondrial cytochrome c oxidase subunit I (COI) sequences confirmed that all collected flatworms were P. manokwari and placed them in the "world haplotype" clade alongside other previously reported specimens from France, Florida (USA), Puerto Rico, Singapore, French Polynesia, New Caledonia, and the Solomon Islands. In addition, infective stage larvae (L3) of the nematode Angiostrongylus malaysiensis were found in the flatworm specimens, with a 12.4% infection rate (15/121 specimens examined). Platydemus manokwari occurrence in Thailand and its capacity to carry L3 of Angiostrongylus should be of concern to biodiversity conservation and human health practitioners, because this invasive flatworm species may be involved in the life cycle of angiostrongylid worms in Thailand.

RevDate: 2018-09-20

Khim JS, Hong S, Yoon SJ, et al (2018)

A comparative review and analysis of tentative ecological quality objectives (EcoQOs) for protection of marine environments in Korea and China.

Environmental pollution (Barking, Essex : 1987), 242(Pt B):2027-2039.

Ecological quality objectives (EcoQOs), as tools for implementing ecosystem approach, have long been acknowledged to protect the marine ecosystems and fisheries in regional seas through joint efforts by surrounding countries over the past decade. The present review analyzed the best available meta-data relating to the five ecosystem elements that were recently proposed by the Northwest Pacific Action Plan to evaluate the current status of coastal ecosystem health in marine environment of the Yellow Sea. We suggested the six tentative EcoQOs among five ecological quality elements including: 1) biological and habitat diversity; 2) invasive species; 3) eutrophication; 4) pollutants; and 5) marine litters. Environmental status was assessed, depending on the EcoQOs targets, by comparison to the world average values, existing environmental standards, or reported values of other regional seas. Results of analysis revealed that among the six tentative EcoQOs, two target objectives to marine biodiversity and concentrations of nutrients (viz., DIN and DIP) were met towards good environmental status. Whilst, three EcoQOs relating to hypoxia and red-tide, pollutants (persistent toxic substances and metals), and marine litters (including microplastics) did not meet and one relating to invasive species could not be judged due to insufficient data sets. The biggest weak point for developing suitable EcoQOs and assessing status of ecosystem health could be insufficient meta-data sets available and/or discrepancy in methodological details cross the data-sets or between the two targeted countries. Thus, the cooperation of neighboring countries, viz., Korea and China for the Yellow Sea, is necessary for the ecosystem based management of our regional sea in the future. Overall, this first time review for the assessment of target tentative EcoQOs in the Yellow Sea region encompassing coasts of Korea and China would provide a better understanding of the current status of environmental pollution and ecosystem health.

RevDate: 2018-09-20
CmpDate: 2018-09-20

Santos MEA, JD Reimer (2018)

Rafting in Zoantharia: a hitchhiker's guide to dispersal?.

Marine pollution bulletin, 130:307-310.

The increasing availability of human-made structure in the oceans coupled with climate changes may lead to the range expansion of species able to disperse by rafting. In this study, we report on zoantharian species of genera Isaurus, Palythoa, Umimayanthus and Zoanthus covering artificial substrates in locations in both the Atlantic and Pacific oceans. Moreover, we reviewed observations of additional zoantharians as macrofouling organisms, and discuss the possible role of rafting in the dispersal of this cosmopolitan group. Traits reported to some zoantharian species, such as hermaphroditism and resistance to desiccation, support their dispersal potential by drifting attached to floating objects. Further reports of zoantharian species covering floating artificial structures and natural debris are needed to increase our knowledge of dispersal mechanisms in the oceans. Additionally, this information is essential to monitor and manage possible exotic species invasions, especially for zoantharian species that are common in the aquarium trade.

RevDate: 2018-09-19

Stevens CJ (2018)

Recent advances in understanding grasslands.

F1000Research, 7:.

Grasslands are a vitally important ecosystem, supporting a wide range of ecosystem services and high levels of biodiversity. As a consequence, they have long been a focus for ecologists, playing host to some of the world's longest-running ecological experiments and providing the inspiration for many long-standing theories and debates. Because the field of grassland ecology is broad, encompassing many areas of ecology, this article picks some areas of particular debate and development to look at recent advances. The areas include relationships between diversity and productivity, ecosystem stability and ecosystem service provision, global change threats from nutrient addition, invasive species, climate change, and plant soil interactions.

RevDate: 2018-09-19
CmpDate: 2018-09-19

Szymura TH, Szymura M, Zając M, et al (2018)

Effect of anthropogenic factors, landscape structure, land relief, soil and climate on risk of alien plant invasion at regional scale.

The Science of the total environment, 626:1373-1381.

We compared the effectiveness of explanatory variables representing different environmental spheres on the risk of alien plant invasion. Using boosted regression trees (BRT), we assessed the effect of anthropogenic factors, soil variables, land relief, climate and landscape structure on neophyte richness (NR) (alien plant species introduced after the 15th century). Data on NR were derived from a 2 × 2 km grid covering a total area of 31,200 km2 of the Carpathian massif and its foreground, Central Europe. Each of the examined environmental spheres explained NR, but their explanatory ability varied more than two-folds. Climatic variables explained the highest fraction of deviation, followed by anthropogenic factors, soil type, land relief and landscape structure. The global model, which incorporated crucial variables from all studied environmental spheres, had the best explanatory ability. However, the explained deviation was far smaller than the sum of the deviations explained by the single-sphere models. The global model showed that the deviation that could be explained by variables representing particular spheres, overlapped. The variables representing landscape structure were not included in the global model as they were found to be redundant. Finally, the climatic variables explained a smaller fraction of the deviation than the anthropogenic factors. The partial dependency plots allowed the assessment of the course of dependencies between NR and particular explanatory variables after eliminating the average effect of all other variables. The relationships were usually curvilinear and revealed some values of environmental variables beyond which NR changed considerably.

RevDate: 2018-09-18

Nogueira AF, Pereira JL, Antunes SC, et al (2018)

Effects of zinc pyrithione on biochemical parameters of the freshwater Asian clam Corbicula fluminea.

Aquatic toxicology (Amsterdam, Netherlands), 204:100-106 pii:S0166-445X(18)30336-9 [Epub ahead of print].

Zinc pyrithione (ZnPT) is an organometallic biocide with bactericide, algaecide, and fungicide activity. Considering this biological activity, ZnPT has been used in anti-fouling paints, and also in human therapeutics and cosmetics, in shampoos to treat dandruff and seborrhoea. Despite its potential uses and consequent presence in the aquatic environment, the ecotoxicological effects of ZnPT are poorly understood. This work aims to characterise the effects of ZnPT in biochemical parameters of the Asian clam, one of the most invasive bivalves known for its biofouling action in hydro-dependent industries, using a classical (LC50 determination) and a biomarker-based approach (quantification of the activities of catalase, GSTs, and acetylcholinesterase, and also the muscle glycogen content). The here determined LC50-96 h for zinc pyrithione was 2.17 mg/L. ZnPT caused significant increases in the activity of catalase and of cholinesterases. These findings evidence the pro-oxidative effects caused by the metabolism of ZnPT. Despite the absence of clear effects, it is important to stress that the presence of ZnPT in the wild is usually accompanied by other pyrithiones, whose co-existence can contribute to the exertion of considerable toxic effects.

RevDate: 2018-09-18

Gariepy TD, Bruin A, Konopka J, et al (2018)

A modified DNA barcode approach to define trophic interactions between native and exotic pentatomids and their parasitoids.

Molecular ecology [Epub ahead of print].

The establishment of invasive Halyomorpha halys (Stål) outside of its native range may impact native species assemblages, including other pentatomids and their scelionid parasitoids. This has generated interest in defining species diversity and host-parasitoid associations in this system to better understand the impact of invasive alien species on trophic interactions in invaded regions. Information on scelionid-pentatomid associations in natural habitats is lacking, and species-level identification of these associations can be tenuous using rearing and dissection techniques. Naturally occurring pentatomid eggs were collected in areas where H. halys has established in Canada and were analysed using a modified DNA barcoding approach to define species-level trophic interactions. Identification was possible for >90% of egg masses. Eleven pentatomid and five scelionid species were identified, and trophic links were established. Approximately 70% of egg masses were parasitized; parasitism and parasitoid species composition were described for each species. Telenomus podisi Ashmead was the dominant parasitoid and was detected in all host species. Trissolcus euschisti Ashmead was detected in several host species, but was significantly more prevalent in Chinavia hilaris (Say) and Brochymena quadripustulata (Fabricius). Trissolcus brochymenae Ashmead and Tr. thyantae Ashmead were recorded sporadically. Parasitism of H. halys was 55%, and this species was significantly less likely to be parasitized than native pentatomids. The scelionid species composition of H. halys consisted of Te. podisi, Tr. euschisti, and Tr. thyantae. Although these species cannot develop in fresh H. halys eggs, we demonstrate that parasitoids attempt to exploit this host under field conditions. This article is protected by copyright. All rights reserved.

RevDate: 2018-09-18

Cuthbert RN, Dickey JWE, McMorrow C, et al (2018)

Resistance is futile: lack of predator switching and a preference for native prey predict the success of an invasive prey species.

Royal Society open science, 5(8):180339 pii:rsos180339.

Invasive species continue to severely impact biodiversity, yet predicting the success or failure of introduced species has remained elusive. In particular, the relationship between community invasibility and native species diversity remains obscure. Here, we apply two traditional ecological concepts that inform prey population stability and hence invasibility. We first show that the native predatory crustacean Gammarus duebeni celticus exhibited similar type II (destabilizing) functional responses (FRs) towards native mayfly prey and invasive amphipod prey, when these prey species were presented separately. However, when the two prey species were presented simultaneously, the predator did not exhibit prey switching, instead consuming disproportionately more native prey than expected from the relative abundance of native and invasive species. These consumptive propensities foster reductions of native prey, while simultaneously limiting biotic resistance against the invasive species by the native predator. Since our theoretical considerations and laboratory results match known field invasion patterns, we advocate the increased consideration of FR and prey switching studies to understand and predict the success of invasive species.

RevDate: 2018-09-18

Visha A, Gandhi N, Bhavsar SP, et al (2018)

Assessing mercury contamination patterns of fish communities in the Laurentian Great Lakes: A Bayesian perspective.

Environmental pollution (Barking, Essex : 1987) pii:S0269-7491(18)31265-X [Epub ahead of print].

We examine the spatio-temporal trends of mercury, a well-known global legacy contaminant, in eleven fish species across all of the Canadian Great Lakes. These particular fish species are selected based on their ecological, commercial, and recreational importance to the biodiversity and fishing industry of the Great Lakes. We present a two-pronged Bayesian methodological framework to rigorously assess mercury temporal trends across multiple fish species and locations. In the first part of our analysis, we develop dynamic linear models to delineate the total mercury levels and rates of change, while explicitly accounting for the covariance between fish length and mercury levels in fish tissues. We then use hierarchical modelling to evaluate the spatial variability of mercury contamination between nearshore and offshore locations, as well as to examine the hypothesis that invasive species have induced distinct shifts on fish mercury contamination trends. Our analysis suggests that the general pattern across the Great Lakes was that the elevated mercury concentrations during the 1970s had been subjected to a declining trend throughout the late 1980s/early 1990s, followed by a gradual stabilization after the late 1990s/early 2000s. The declining trend was more pronounced with top fish predators, whereas benthivorous fish species mainly underwent wax-and-wane cycles with a weaker evidence of a long-term declining trend. Historically contaminated regions, designated as Areas of Concern, and bays receiving riverine inputs are still characterized by mercury concentrations that can lead to consumption restrictions. Lake Erie displayed the lowest mercury levels across all the fish species examined. However, several species of commercial importance showed a reversing (increasing) trend in the 2000s, although their current levels do not pose any major concerns for consumption advisories. These recent trend reversals can be linked with systematic shifts in energy trophodynamics along with the food web alterations induced from the introduction of non-native species, and the potentially significant fluxes from the atmosphere.

RevDate: 2018-09-17

Hédl R, Šipoš J, Chudomelová M, et al (2017)

Dynamics of herbaceous vegetation during four years of experimental coppice introduction.

Folia geobotanica, 52(1):83-99.

Understanding the effects of coppicing on forest ecosystems is important for progress towards sustainable forest management. A newly established coppicing experiment in a secondary temperate deciduous forest in the SE Czech Republic provides a rather unique insight into succession driven by canopy thinning in a forest still lacking species typical for forests established since long time ago. Herbaceous layer vegetation was monitored for four subsequent years in 2012-2015. We focused on the influence of canopy thinning intensity in two different forest types defined by dominant tree species (oak and lime). Our results showed that the opening of the canopy had immediate effects on herbaceous vegetation. Coverage, species richness and compositional patterns followed the coppicing intensity gradient. The dominant tree species had contrasting effects. Under oak, the reaction to coppicing was weak. Under lime, strong reaction both related to coppicing intensity and temporal development was observed. Herbs with short life cycle had the greatest contribution, but perennial grasses also began to increase their coverage after coppicing. Several invasive species, mostly short-lived herbs, emerged but are supposed to retreat as the succession will proceed. We conclude that coppice introduction to a secondary forest led to contrasting patterns related to dominant tree species. The marked difference was probably due to the slow sucession towards a future forest community saturated by species. This process may be now further diversified by coppicing management.

RevDate: 2018-09-17

Lounibos LP, SA Juliano (2018)

Where Vectors Collide: The Importance of Mechanisms Shaping the Realized Niche for Modeling Ranges of Invasive Aedes Mosquitoes.

Biological invasions, 20(8):1913-1929.

The vector mosquitoes Aedes aegypti (L.), native to Africa, and Aedes albopictus (Skuse), native to Asia, are widespread invasives whose spatial distributions frequently overlap. Predictive models of their distributions are typically correlative rather than mechanistic, and based on only abiotic variables describing putative environmental requirements despite extensive evidence of competitive interactions leading to displacements. Here we review putative roles of competition contributing to distribution changes where the two species meet. The strongest evidence for competitive displacements comes from multiple examples of habitat segregation where the two species co-occur and massive reductions in the range and abundance of A. aegypti attributable to A. albopictus invasions in the southeastern U.S.A. and Bermuda (U.K). We summarize evidence to support the primacy of asymmetric reproductive interference, or satyrization, and larval resource competition, both favoring A. albopictus, as displacement mechanisms. Where evidence of satyrization or interspecific resource competition is weak, differences in local environments or alternative ecologies or behaviors of these Aedes spp. may explain local variation in the outcomes of invasions. Predictive distribution modeling for both these major disease vectors needs to incorporate species interactions between them as an important process that is likely to limit their realized niches and future distributions. Experimental tests of satyrization and resource competition are needed across the broad ranges of these species, as are models that incorporate both reproductive interference and resource competition to evaluate interaction strengths and mechanisms. These vectors exemplify how fundamental principles of community ecology may influence distributions of invasive species.

RevDate: 2018-09-17

Guiaşu RC, CW Tindale (2018)

Logical fallacies and invasion biology.

Biology & philosophy, 33(5):34.

Leading invasion biologists sometimes dismiss critics and criticisms of their field by invoking "the straw man" fallacy. Critics of invasion biology are also labelled as a small group of "naysayers" or "contrarians", who are sometimes engaging in "science denialism". Such unfortunate labels can be seen as a way to possibly suppress legitimate debates and dismiss or minimize reasonable concerns about some aspects of invasion biology, including the uncertainties about the geographic origins and complex environmental impacts of species, and the control programs against species perceived as "invasive". In assessing the quality of the debate in this area, we examine the validity of the use of various strategies, including the "straw man" concept, and explore a range of potential logical fallacies present in some recent prominent discussions about invasion biology and so-called "invasive" species. The goal is to add some clarity to the concepts involved, point out some problematic issues, and improve the quality of the debates as the discussions move forward.

RevDate: 2018-09-17
CmpDate: 2018-09-17

Pickett T, AA David (2018)

Global connectivity patterns of the notoriously invasive mussel, Mytilus galloprovincialis Lmk using archived CO1 sequence data.

BMC research notes, 11(1):231 pii:10.1186/s13104-018-3328-3.

OBJECTIVE: The invasive mussel, Mytilus galloprovincialis has established invasive populations across the globe and in some regions, have completely displaced native mussels through competitive exclusion. The objective of this study was to elucidate global connectivity patterns of M. galloprovincialis strictly using archived cytochrome c oxidase 1 sequence data obtained from public databases. Through exhaustive mining and the development of a systematic workflow, we compiled the most comprehensive global CO1 dataset for M. galloprovincialis thus far, consisting of 209 sequences representing 14 populations. Haplotype networks were constructed and genetic differentiation was assessed using pairwise analysis of molecular variance.

RESULTS: There was significant genetic structuring across populations with significant geographic patterning of haplotypes. In particular, South Korea, South China, Turkey and Australasia appear to be the most genetically isolated populations. However, we were unable to recover a northern and southern hemisphere grouping for M. galloprovincialis as was found in previous studies. These results suggest a complex dispersal pattern for M. galloprovincialis driven by several contributors including both natural and anthropogenic dispersal mechanisms along with the possibility of potential hybridization and ancient vicariance events.

RevDate: 2018-09-16

Zhang F, Li Q, Yerger EH, et al (2018)

AM fungi facilitate the competitive growth of two invasive plant species, Ambrosia artemisiifolia and Bidens pilosa.

Mycorrhiza pii:10.1007/s00572-018-0866-4 [Epub ahead of print].

Invasive species often cause enormous economic and ecological damage, and this is especially true for invasive plants in the Asteraceae family. Arbuscular mycorrhizal fungi (AMF) play an important role in the successful invasion by exotic plant species because of their ability to promote growth and influence interspecific competition. However, few studies have evaluated the effects of invasive Asteraceae species on AMF diversity and how feedback mechanisms during competition with native species subsequently affect the accumulation of nutrient resources. Two exotic Asteraceae, Ambrosia artemisiifolia and Bidens pilosa, were monitored during competition with a native grass species, Setaria viridis, which is being replaced by these exotic species in natural areas around the study site. From these species continuously maintained in a field plot for 5 years, we collected the rhizosphere soil and cloned and identified soil AMF. Furthermore, AM fungal spores were isolated from rhizosphere soil of the two invasive species and used as inoculum in greenhouse experiments, to compare growth and nutrient accumulation during competition. The results indicate that although the AMF diversity in the rhizosphere soil of A. artemisiifolia and B. pilosa differed, the three most abundant species (Septoglomus viscosum, Septoglomus constrictum, Glomus perpusillum) were identical. The addition of AMF inoculum changed the competition between the plants, increasing the competitive ability of the invasives and decreasing that of the native. The results show a similar AMF community composition between A. artemisiifolia and B. pilosa, increased AMF root colonization of the invasive species during competition, AMF-enhanced N accumulation, and AMF-facilitated competitive growth of the invasive species.

RevDate: 2018-09-16

Wilkins KE, Prowse TAA, Cassey P, et al (2018)

Pest demography critically determines the viability of synthetic gene drives for population control.

Mathematical biosciences pii:S0025-5564(18)30117-2 [Epub ahead of print].

Synthetic gene drives offer a novel solution for the control of invasive alien species. CRISPR-based gene drives can positively bias their own inheritance, and comprise a DNA sequence that is replicated by homologous recombination. Since gene drives can be positioned to silence fertility or developmental genes, they could be used for population suppression. However, the production of resistant alleles following self-replication errors threatens the technology's viability for pest eradication in real-world applications. Further, a robust assessment of how pest demography impacts the expected progression of gene drives through populations is currently lacking. We used a deterministic, two-sex, birth-death model to investigate how demographic assumptions affect the efficiency of suppression drives for controlling invasive rodents on islands, for two different gene-drive strategies. We show that mass-action reproduction, which is commonly assumed in previous models, results in overly optimistic eradication outcomes when compared to the more realistic assumption of polygynous breeding. When polygyny was assumed, both gene-strategies failed due to the evolution of resistance unless a reproductive Allee effect (reduced reproductive rates at low population density) was also included; although model outcomes were highly sensitive to the strength of this effect. Increasing the size of the initial gene-drive introduction (up to 10% of carrying capacity) had little impact on population outcomes. Understanding the demography of a population targeted for eradication is critical before the viability of gene-drive suppression can be adequately assessed.

RevDate: 2018-09-14

Paini DR, Mwebaze P, Kuhnert PM, et al (2018)

Global establishment threat from a major forest pest via international shipping: Lymantria dispar.

Scientific reports, 8(1):13723 pii:10.1038/s41598-018-31871-y.

The global shipping network is widely recognised as a pathway for vectoring invasive species. One species of particular concern is Lymantria dispar (gypsy moth). Two subspecies, L. d. asiatica and L. d. japonica (herein referred to as Asian Gypsy Moth - AGM) are of considerable concern as ships arriving to a number of countries have been found carrying AGM egg masses. However, ships carrying AGM eggs can only threaten a country at ports located in a climatically suitable region. We present a CLIMEX model of climate suitability and combine this with international shipping to estimate the global threat from AGM. We find that for the USA more than half of international ships (approximately 18,000 ships) arrive to climatically suitable ports. Other countries with a large number of ships arriving to ports with suitable climates include Canada and Brazil. This is the first global analysis of the invasion threat from AGM, and we recommend countries focus AGM-inspection programs towards ships arriving at ports found within climatically suitable regions.

RevDate: 2018-09-14
CmpDate: 2018-09-14

Costa APL, Takemoto RM, JRS Vitule (2018)

Metazoan parasites of Micropterus salmoides (Lacépède 1802) (Perciformes, Centrarchidae): a review with evidences of spillover and spillback.

Parasitology research, 117(6):1671-1681.

Among the topics related to invasion science, the least studied are parasite co-introduction and spillback. This leads to an uncertainty in invasion ecology theories and applications to management. Therefore, the present study brings a systematic review of published information on the metazoan parasite fauna of Micropterus salmoides, a widely introduced fish, with the aim of comparing information about the composition and richness of the associated parasite communities in its native and introduced regions. This review demonstrates that there were twice as many studies of M. salmoides in its native region in comparison with introduced regions, although most of the studies focused on the analysis of a single species or taxon of parasite. This bias impacts the number of parasite species observed and, consequently, the apparent importance of enemy release in introduced regions. The composition of the parasite community in the two regions showed high similarity, which indicates the introduction and acquisition of parasites in introduced regions. Otherwise, there was no pattern related to the geographic distance, highlighting the influence of the propagule pressure and vector strength on the introduction of novel parasites. This illustrates the importance of vector strength on fish-parasite co-introduction and the necessity of new research examining host-parasite interactions with the parasite community of the invaded ecosystems. We still do not know the major influences of the composition of the parasite fauna of M. salmoides or how we can manage to develop a more restrictive vector pathway of introduction. The future of our ecosystems depends on how to account for current and future interactions among novel interactions, habitat, and climate change.

RevDate: 2018-09-13

Cardilini APA, Micallef S, Bishop VR, et al (2018)

Environmental Influences on Neuromorphology in the Non-Native Starling Sturnus vulgaris.

Brain, behavior and evolution pii:000491672 [Epub ahead of print].

Cognitive traits are predicted to be under intense selection in animals moving into new environments and may determine the success, or otherwise, of dispersal and invasions. In particular, spatial information related to resource distribution is an important determinant of neural development. Spatial information is predicted to vary for invasive species encountering novel environments. However, few studies have tested how cognition or neural development varies intraspecifically within an invasive species. In Australia, the non-native common starling Sturnus vulgaris inhabits a range of habitats that vary in seasonal resource availability and distribution. We aimed to identify variations in the brain mass and hippocampus volume of starlings in Australia related to environmental variation across two substantially different habitat types. Specifically, we predicted variation in brain mass and hippocampal volume in relation to environmental conditions, latitude, and climatic variables. To test this, brain mass and volumes of the hippocampus and two control brain regions (telencephalon and tractus septomesencephalicus) were quantified from starling brains gathered from across the species' range in south eastern Australia. When comparing across an environmental gradient, there was a significant interaction between sex and environment for overall brain mass, with greater sexual dimorphism in brain mass in inland populations compared to those at the coast. There was no significant difference in hippocampal volume in relation to environmental measures (hippocampus volume, n = 17) for either sex. While these data provide no evidence for intraspecific environmental drivers for changes in hippocampus volume in European starlings in Australia, they do suggest that environmental factors contribute to sex differences in brain mass. This study identifies associations between the brain volume of a non-native species and the environment; further work in this area is required to elucidate the mechanisms driving this relationship.

RevDate: 2018-09-13

Visha A, Gandhi N, Bhavsar SP, et al (2018)

A Bayesian assessment of polychlorinated biphenyl contamination of fish communities in the Laurentian Great Lakes.

Chemosphere, 210:1193-1206.

Polychlorinated biphenyl (PCB) contamination has historically posed constraints on the recreational and commercial fishing industry in the Great Lakes. Empirical evidence suggests that PCB contamination represents a greater health risk from fish consumption than other legacy contaminants. The present study attempts a rigorous assessment of the spatio-temporal PCB trends in multiple species across the Canadian waters of the Great Lakes. We applied a Bayesian modelling framework, whereby we initially used dynamic linear models to delineate PCB levels and rates of change, while accounting for the role of fish length and lipid content as covariates. We then implemented Bayesian hierarchical modelling to evaluate the temporal PCB trends during the dreissenid pre- and post-invasion periods, as well as the variability among and within the water bodies of the Great Lakes system. Our analysis indicates that Lake Ontario is characterized by the highest PCB levels among nearly all of the fish species examined. Historically contaminated local areas, designated as Areas of Concern, and embayments receiving riverine inputs displayed higher concentrations within each of the water bodies examined. The general temporal trend across the Great Lakes was that the high PCB concentrations during the early 1970s followed a declining trajectory throughout the late 1980s/early 1990s, likely as a result of the reductions in industrial emissions and other management actions. Nonetheless, after the late 1990s/early 2000s, our analysis provided evidence of a decline in the rate at which PCB concentrations in fish were dropping, accompanied by a gradual establishment of species-specific, steady-state concentrations, around which there is considerable year-to-year variability. The overall trends indicate that reduced contaminant emissions have brought about distinct beneficial changes in fish PCB concentrations, but past historical contamination along with other external or internal stressors (e.g., invasive species, climate change) continue to modulate the current levels, thereby posing potential risks to humans through fish consumption.

RevDate: 2018-09-13

Wei H, Huang M, Quan G, et al (2018)

Turn bane into a boon: Application of invasive plant species to remedy soil cadmium contamination.

Chemosphere, 210:1013-1020.

Cadmium (Cd) is one of the mostly hazardous soil pollutants and has threatened human health by accumulating in grains of crops. Phytoremediation is a promising technique to remedy soil Cd contamination, but reported Cd hyperaccumulators remain limited. In this study, we explored potential applicability of three invasive plant species (Chromolaena odorata, Bidens pilosa and Praxelis clematidea) to remove soil Cd using greenhouse experiment. Results showed that the three species grew well with Cd treatments compared to the controlled individuals, suggesting that the species had high Cd tolerance by physiological adjustments such as up-regulating the antioxidant enzyme activities. The only exception was that the height of P. clematidea in the 60 mg kg-1 Cd treatment was less than that in the control. Within the tested Cd concentration range, the C. odorata exhibited high bioaccumulation characteristics that meet the recommended standards to identify as a hyperaccumulator (shoot Cd concentration > 100 mg kg-1 with bioconcentration and transfer factors > 1). The other two species had also the shoot bioconcentration factor and transfer factor greater than one, while the shoot Cd concentration was relatively lower. Our results highlight a potential applicability of the invasive species used in this study for remediation of the soil Cd contamination, which turns bane into a boon.

RevDate: 2018-09-12

Parm L, Štšepetova J, Eelmäe I, et al (2018)

Genetic relatedness of Gram-negative bacteria colonizing gut and skin of neonates and mother's own milk.

Journal of perinatology : official journal of the California Perinatal Association pii:10.1038/s41372-018-0220-x [Epub ahead of print].

OBJECTIVE: We described colonization of mother's own milk with Gram-negative bacteria and its relationship with neonatal colonization.

STUDY DESIGN: Gram-negative bacteria isolated from weekly collected stool, skin and mother's own milk of hospitalized preterm (n = 49) and healthy term neonates (n = 20) were genotyped. Colonization-related factors were determined by logistic regression.

RESULTS: Gram-negative bacteria were isolated from mother's own milk of 22.4% (n = 11) and 15% (n = 3) of mothers of preterm and term neonates, respectively. According to pulsed-field gel electrophoresis genetically similar strains were present in mother's own milk and gut of 8.2% (n = 4) of mother-preterm neonate, but none of mother-term neonate pairs. In three of four late-onset sepsis caused by Gram-negative bacteria, colonization of gut, but not mother's own milk, with invasive species preceded late-onset sepsis.

CONCLUSIONS: Colonization of mother's own milk with Gram-negative bacteria is uncommon and transmission to neonatal gut may occur in less than one-tenth of neonate-mother pairs.

RevDate: 2018-09-12
CmpDate: 2018-09-12

Oliveira-Silva LRB, Campêlo AC, Lima IMS, et al (2018)

Can a Non-Native Primate Be a Potential Seed Disperser? A Case Study on Saimiri sciureus in Pernambuco State, Brazil.

Folia primatologica; international journal of primatology, 89(2):138-149.

The interaction between native fleshy-fruit plants and introduced fruit consumers contributes to the dynamics of highly fragmented environments. Such interactions can occur through pollination and seed dispersal. Here, we investigated the potential of seed dispersing by a non-native primate, the squirrel monkey (Saimiri sciureus), in an urban Atlantic forest fragment in north-eastern Brazil. Fleshy fruits from non-native plants were preferentially exploited by the squirrel monkeys. We measured 147 seeds (width and length) from 20 of 106 faecal samples. The dispersed seeds were from five plant species (four families). We found a positive correlation between the size of seeds found in faecal samples with their availability in the habitat. Only one seed was found visually damaged after passage through the squirrel monkeys' guts. The defecated seeds were uniformly distributed (variance to mean ratio index) in the home range of squirrel monkeys, and there was a lack of specific latrines (i.e., habitat preference for defecation). Our data provide evidence that non-native S. sciureus may in be (i) acting as a potential seed disperser of native plants in the Atlantic forest fragment, (ii) contributing to the ecological role of native frugivores, and (iii) potentially contributing to the regeneration process of the highly degraded study site.

RevDate: 2018-09-11

Gantchoff MG, Wilton CM, JL Belant (2018)

Factors influencing exotic species richness in Argentina's national parks.

PeerJ, 6:e5514 pii:5514.

Exotic species introductions are a global phenomenon and protected areas are susceptible to them. Understanding the drivers of exotic species richness is vital for prioritizing natural resource management, particularly in developing countries with limited resources. We analyzed the influence of coarse resolution factors on exotic species richness (plants, mammals, and birds) in Argentina's National Parks System. We collected data on native species richness, year of park formation, park area, region, elevation range, number of rivers crossing area boundaries, roads entering area, mean annual rainfall, mean annual temperature, mean annual number of visitors, and Human Influence Index within and surrounding each park. We compiled 1,688 exotic records in 36 protected areas: 83% plants and 17% animals (9.5% mammals, 5.5% birds, 1.5% fishes, 0% amphibians, 0% reptiles). The five parks with the most exotic species (all taxa combined) were in north Patagonia. Exotic grasses were the most common exotic plants, and within animals, lagomorphs and feral ungulates were remarkably widespread. Exotic plant richness was mostly influenced by temperature and native plant richness, while exotic mammal and bird richness was driven mostly by anthropogenic variables, with models explaining 36-45% of data deviance. Most variables that positively influenced exotic taxa were indirectly related to an increase in spatial heterogeneity (natural or anthropogenic), suggesting greater niche space variability as facilitators of exotic richness increase. Additional data are needed to further investigate the patterns and mechanisms of exotic species richness in protected areas, which will help to prioritize the greatest needs of monitoring and management.

RevDate: 2018-09-11

Li K, Scott AM, Fissette SD, et al (2018)

Petromylidenes A⁻C: 2-Alkylidene Bile Salt Derivatives Isolated from Sea Lamprey (Petromyzon marinus).

Marine drugs, 16(9): pii:md16090308.

Three novel bile acid derivatives, petromylidenes A⁻C (1⁻3), featuring uncommon alkylidene adductive scaffolds, were isolated from water conditioned with sexually mature male sea lampreys (Petromyzon marinus). Their structures were elucidated by mass spectrometry and NMR spectroscopy, and by comparison to spectral data of related structures. The identification of compounds 1⁻3, further illustrates the structural diversity of the 5α bile salt family. Compounds 1⁻3 exhibited notable biological properties as well, including high olfactory potencies in adult sea lampreys and strong behavioral attraction of ovulated female sea lampreys. Electro-olfactogram recordings indicated that the limit of detection for 1 was 10-9 M, 2 was 10-11 M, and 3 was less than 10-13 M. These results suggested 1⁻3 were likely male pheromones, which guide reproductive behaviors in the sea lamprey.

RevDate: 2018-09-11
CmpDate: 2018-09-11

Anonymous (2018)

Bloody battles as birds maul European bats.

Nature, 557(7705):282.

RevDate: 2018-09-11
CmpDate: 2018-09-11

O'Loughlin LS, PT Green (2016)

Habitat augmentation drives secondary invasion: an experimental approach to determine the mechanism of invasion success.

Ecology, 97(9):2458-2469.

The entry of secondary invaders into, or their expansion within, native communities is contingent on the changes wrought by other (primary) invaders. When primary invaders have altered more than one property of the recipient community, standard descriptive and modeling approaches only provide a best guess of the mechanism permitting the secondary invasion. In rainforest on Christmas Island, we conducted a manipulative field experiment to determine the mechanism of invasion success for a community of land snails dominated by non-native species. The invasion of rainforest by the yellow crazy ant (Anoplolepis gracilipes) has facilitated these land snails, either by creating enemy-free space and/or increased habitat and resources (in the form of leaf litter) through the removal of the native omnivorous-detritivorous red land crab (Gecarcoidea natalis). We manipulated predator densities (high and low) and leaf litter (high and low) in replicated blocks of four treatment combinations at two sites. Over the course of one wet season (five months), we found that plots with high leaf litter biomass contained significantly more snails than those with low biomass, regardless of whether those plots had high or low predation pressure, at both the site where land crabs have always been abundant, and at the site where they have been absent for many years prior to the experiment. Each site was dominated by small snail species (<2 mm length), and through handling size and predation experiments we demonstrated that red crabs tend not to handle and eat snails of that size. These results suggest that secondary invasion by this community of non-native land snails is facilitated most strongly by habitat and resource augmentation, an indirect consequence of red land crab removal, and that the creation of enemy-free space is not important. By using a full-factorial experimental approach, we have confidently determined-rather than inferred-the mechanism by which primary invaders indirectly facilitate a community of secondary invaders.

RevDate: 2018-09-09

Kurucz K, Kiss V, Zana B, et al (2018)

Filarial nematode (order: Spirurida) surveillance in urban habitats, in the city of Pécs (Hungary).

Parasitology research pii:10.1007/s00436-018-6066-5 [Epub ahead of print].

As part of the seasonal mosquito control activities in the city of Pécs (Baranya County, Hungary), a total of 1123 adult female mosquitoes belonging to 18 species (including the invasive species Aedes koreicus) were collected from human-inhabited areas, using CO2-baited traps, during two consecutive years. To survey the presence and prevalence of filarial parasites in these mosquitoes, we performed a molecular survey for filarial DNA, attempted by PCR using generic primers (COI), and followed by DNA sequencing. Filaroid nematode DNA was detected in 4% of investigated mosquito pools. Out of 410 pools, 9 pools of mosquitoes were positive for Dirofilaria repens (Aedes vexans, Aedes koreicus, Coquillettidia richiardii), and/or Dirofilaria immitis (Ae. vexans, Cq. richiardii), and further 8 pools were positive for Setaria tundra (Ae. vexans, Cq. richiardii). Our study provides novel insight for prevalence of filaroid nematodes in mosquitoes occurring in close proximity to humans, thereby highlights the possible human and veterinary health importance of these mosquito species, including the recently introduced invasive mosquito Ae. koreicus.

RevDate: 2018-09-07

Bieńkowski AO, MJ Orlova-Bienkowskaja (2018)

Alien leaf beetles (Coleoptera, Chrysomelidae) of European Russia and some general tendencies of leaf beetle invasions.

PloS one, 13(9):e0203561 pii:PONE-D-18-04487.

Invasions of leaf beetles can cause tremendous economic consequences because some of these insects become major pests in invaded territories. We present the first inventory of alien Chrysomelidae of European Russia that appeared in the region in the 20th and 21st centuries (9 species) with analysis of the history of their invasions and detailed maps of distribution. This case study revealed some general tendencies of invasions of leaf beetles: (1) Recently, a dramatic increase in the rate of Chrysomelidae invasions is observed, which reflects the increase in international trade of living plants; (2) Alien leaf beetles can spread quickly, occupying almost all of Europe within several decades; (3) When the range of some leaf beetle species is quickly expanding, or when the species has been recorded established somewhere outside the native range, this species should be regarded as a potential invader worldwide. and (4) Alien leaf beetles usually occur on alien or cultivated plants, but some become naturalized in native communities. The specific information was the following. Two species native to the Mediterranean region, Chrysolina americana (feeds on Rosmarinus and Lavandula) and Leptomona erythrocephala (feeds on Lotus corniculatus) were recorded in European Russia for the first time. A polyphagous pest of floriculture Luperomorpha xanthodera native to China and Korea and a pest of soybeans Medythia nigrobilineata native to east Asia have been in the region since 2016. A pest of tobacco Epitrix hirtipennis native to North America has occurred since 2011. A pest of corn Diabrotica virgifera was intercepted at the border of Russia in 2011 but has not established. Three alien species have been in the region since the 20th century: Zygogramma suturalis introduced from North America for control of Ambrosia, Phyllotreta reitteri native to Afghanistan and Tajikistan and feeding on Lepidium latifolium, and the Colorado potato beetle Leptinotarsa decemlineata.

RevDate: 2018-09-07
CmpDate: 2018-09-07

Blaser S, Diem H, von Felten A, et al (2018)

From laboratory to point of entry: development and implementation of a loop-mediated isothermal amplification (LAMP)-based genetic identification system to prevent introduction of quarantine insect species.

Pest management science, 74(6):1504-1512.

BACKGROUND: Rapid genetic on-site identification methods at points of entry, such as seaports and airports, have the potential to become important tools to prevent the introduction and spread of economically harmful pest species that are unintentionally transported by the global trade of plant commodities. This paper reports the development and evaluation of a loop-mediated isothermal amplification (LAMP)-based identification system to prevent introduction of the three most frequently encountered regulated quarantine insect species groups at Swiss borders, Bemisia tabaci, Thrips palmi and several regulated fruit flies of the genera Bactrocera and Zeugodacus.

RESULTS: The LAMP primers were designed to target a fragment of the mitochondrial cytochrome c oxidase subunit I gene and were generated based on publicly available DNA sequences. Laboratory evaluations analysing 282 insect specimens suspected to be quarantine organisms revealed an overall test efficiency of 99%. Additional on-site evaluation at a point of entry using 37 specimens performed by plant health inspectors with minimal laboratory training resulted in an overall test efficiency of 95%. During both evaluation rounds, there were no false-positives and the observed false-negatives were attributable to human-induced manipulation errors. To overcome the possibility of accidental introduction of pests as a result of rare false-negative results, samples yielding negative results in the LAMP method were also subjected to DNA barcoding.

CONCLUSION: Our LAMP assays reliably differentiated between the tested regulated and non-regulated insect species within <1 h. Hence, LAMP assays represent suitable tools for rapid on-site identification of harmful pests, which might facilitate an accelerated import control process for plant commodities. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

RevDate: 2018-09-07
CmpDate: 2018-09-07

Gaffke AM, Sing SE, Dudley TL, et al (2018)

Semiochemicals to enhance herbivory by Diorhabda carinulata aggregations in saltcedar (Tamarix spp.) infestations.

Pest management science, 74(6):1494-1503.

BACKGROUND: Semiochemicals for monitoring, attracting or repelling pest and beneficial organisms are increasingly deployed in agricultural and forest systems for pest management. However, the use of aggregation pheromones and host-plant attractants for the express purpose of increasing the efficacy of classical biological control agents of weeds has not been widely reported. Therefore, we conducted field-based assays to determine if a specialized wax-based matrix impregnated with an aggregation pheromone of the northern tamarisk beetle Diorhabda carinulata (Desbrochers) or host-plant volatiles could increase the efficacy of D. carinulata.

RESULTS: The aggregation pheromone and host-plant volatiles were formulated for field application using a wax-based matrix. Reported release rates suggest that this matrix is a viable formulation for enhancing D. carinulata aggregations under field conditions. Pheromone-treated saltcedar plants (Tamarix spp.) not only had higher densities of adult and larval D. carinulata, but also sustained greater levels of foliar damage than control plants. Increased damage from the focused feeding of D. carinulata caused an increase in foliar dieback and decrease in live canopy volume of semiochemical-treated plants.

CONCLUSION: Field deployment of these semiochemical formulations could be useful in directing populations of D. carinulata for increased impact on Tamarix spp. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

RevDate: 2018-09-07
CmpDate: 2018-09-07

Larson CD, Lehnhoff EA, LJ Rew (2017)

A warmer and drier climate in the northern sagebrush biome does not promote cheatgrass invasion or change its response to fire.

Oecologia, 185(4):763-774.

Dryland shrub communities have been degraded by a range of disturbances and now face additional stress from global climate change. The spring/summer growing season of the North American sagebrush biome is projected to become warmer and drier, which is expected to facilitate the expansion of the invasive annual grass Bromus tectorum (cheatgrass) and alter its response to fire in the northern extent of the biome. We tested these predictions with a factorial experiment with two levels of burning (spring burn and none) and three climate treatments (warming, warming + drying, and control) that was repeated over 3 years in a Montana sagebrush steppe. We expected the climate treatments to make B. tectorum more competitive with the native perennial grass community, especially Pseudoroegneria spicata, and alter its response to fire. Experimental warming and warming + drying reduced B. tectorum cover, biomass, and fecundity, but there was no response to fire except for fecundity, which increased; the native grass community was the most significant factor that affected B. tectorum metrics. The experimental climate treatments also negatively affected P. spicata, total native grass cover, and community biodiversity, while fire negatively affected total native grass cover, particularly when climate conditions were warmer and drier. Our short-term results indicate that without sufficient antecedent moisture and a significant disruption to the native perennial grass community, a change in climate to a warmer and drier spring/summer growing season in the northern sagebrush biome will not facilitate B. tectorum invasion or alter its response to fire.

RevDate: 2018-09-07
CmpDate: 2018-09-07

Chung M, Goulet CT, Michelangeli M, et al (2017)

Does personality influence learning? A case study in an invasive lizard.

Oecologia, 185(4):641-651.

Learning is a change in state resulting from new experiences enabling behavioural responses to be adjusted in alignment with external cues. Individuals differ in the speed and accuracy at which they learn. Personality has been postulated as being a major influence on learning ability in terms of attention and encounter rates of environmental cues. This link forms the basis of the cognitive style hypothesis (CSH), predicting that an individual's cognitive style will occur along a fast-slow behavioural gradient. Fast types are characterised as being active, neophilic, and bold individuals who sample their environment rapidly, yet superficially, enabling learning to occur at a higher speed, but at the cost of accuracy. Slow types have the opposite suite of personality traits resulting in them being more accurate flexible learners. Greater level of learning flexibility is thought to help promote invasions success. Here, we test the predictions of the CSH in an invasive lizard (Lampropholis delicata) to determine if personality dictates learning performance in a two-phase associative task. Results indicated that the delicate skink was capable of learning an associative task but only provided partial support for the CSH. Personality was found to influence learning accuracy, however, the direction of that relationship was opposite to that predicted. Instead, fast lizards made fewer mistakes when learning to associate a colour to a goal. These findings highlight the need to further investigate the CSH across taxa and consider its potential as an underlying mechanism of the invasion process.

RevDate: 2018-09-06

Mehmet MI, D'Alessandro S, Pawsey N, et al (2018)

The national, regional and city divide: Social media analysis of stakeholders views regarding biological controls. The public reaction to the carp control herpes virus in Australia.

Journal of environmental management, 227:181-188 pii:S0301-4797(18)30970-8 [Epub ahead of print].

Recent research and practice in environmental management suggest sentiment analysis of social media communication can be a useful tool in stakeholder analysis of environmental policy. This is certainly the case when it comes to the controversial use of biological controls in dealing with invasive species. Current numerical scored approaches of sentiment may not reveal the reasons for support or opposition to environmental policies in this and other areas. In this study, we examine how the use of more in-depth analysis based on what key stakeholders say about this issue in media at a national, city or regional geographic level. The analysis reveals quite different reasons for support and opposition to the biological control of carp in Australia, and that within each stakeholder group it is possible for individuals to hold conflicting views and attitudes on this issue. We find that there are concerns at the national and city level about the impact of the virus and mistrust of government and science and that the carp species may be viewed as a valuable resource. Those responding to regional media expressed hope that the virus may lead to the elimination of the carp problem, however, they were more interested in the possible impact on the local environment. The multi-scaled social media analysis of stakeholder views about the potential biological control of carp in Australia demonstrated how social media comments can be used to explore the nuanced and multidimensional nature of community attitudes and preferences.

RevDate: 2018-09-06

Skubel SA, Dushenkov V, Graf BL, et al (2018)

Rapid, field-deployable method for collecting and preserving plant metabolome for biochemical and functional characterization.

PloS one, 13(9):e0203569 pii:PONE-D-18-12401.

Study of plant metabolome is a growing field of science that catalogs vast biochemical and functional diversity of phytochemicals. However, collecting and storing samples of plant metabolome, sharing these samples across the scientific community and making them compatible with bioactivity assays presents significant challenges to the advancement of metabolome research. We have developed a RApid Metabolome Extraction and Storage (RAMES) technology that allows efficient, highly compact, field-deployable collection and storage of libraries of plant metabolome. RAMES technology combines rapid extraction with immobilization of extracts on glass microfiber filter discs. Two grams of plant tissue extracted in ethanol, using a specially adapted Dremel® rotary tool, produces 25-35 replicas of 10 mm glass fiber discs impregnated with phytochemicals. These discs can be either eluted with solvents (such as 70% ethanol) to study the metabolomic profiles or used directly in a variety of functional assays. We have developed simple, non-sterile, anti-fungal, anti-bacterial, and anti-oxidant assays formatted for 24-multiwell plates directly compatible with RAMES discs placed inside the wells. Using these methods we confirmed activity in 30 out of 32 randomly selected anti-microbial medicinal plants and spices. Seven species scored the highest activity (total kill) in the anti-bacterial (bacteria from human saliva) and two anti-fungal screens (Fusarium spp. and Saccharomyces cerevisiae), providing functional validation of RAMES technology. RAMES libraries showed limited degradation of compounds after 12 months of storage at -20°C, while others remained stable. Fifty-eight percent of structures characterized in the extracts loaded onto RAMES discs could be eluted from the discs without significant losses. Miniaturized RAMES technology, as described and validated in this manuscript offers a labor, cost, and time-effective alternative to conventional collection of phytochemicals. RAMES technology enables creation of comprehensive metabolomic libraries from various ecosystems and geographical regions in a format compatible with further biochemical and functional studies.

RevDate: 2018-09-06

Tang XT, Cai L, Shen Y, et al (2018)

Diversity and evolution of the endosymbionts of Bemisia tabaci in China.

PeerJ, 6:e5516 pii:5516.

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, including members that are pests of global importance. This study presents a screening of B. tabaci species in China for infection by the primary endosymbiont, Portiera aleyrodidarum, and two secondary endosymbionts, Arsenophonus and Cardinium. The results showed that P. aleyrodidarum was detected in all B. tabaci individuals, while Arsenophonus was abundant in indigenous species of B. tabaci Asia II 1, Asia II 3, and China 1 but absent in the invasive species, Middle East-Asia Minor 1 (MEAM1); Cardinium presented in the Mediterranean (MED), Asia II 1 and Asia II 3 species but was rarely detected in the MEAM1 and China 1 species. Moreover, phylogenetic analyses revealed that the P. aleyrodidarum and mitochondrial cytochrome oxidase 1 (mtCO1) phylograms were similar and corresponding with the five distinct cryptic species clades to some extent, probably indicating an ancient infection followed by vertical transmission and subsequent co-evolutionary diversification. In contrast, the phylogenetic trees of Arsenophonus and Cardinium were incongruent with the mtCO1 phylogram, potentially indicating horizontal transmission in B. tabaci cryptic species complex. Taken together, our study showed the distinct infection status of endosymbionts in invasive and indigenous whiteflies; we also most likely indicated the co-evolution of primary endosymbiont and its host as well as the potential horizontal transfer of secondary endosymbionts.

RevDate: 2018-09-06

Doizy A, Barter E, Memmott J, et al (2018)

Impact of cyber-invasive species on a large ecological network.

Scientific reports, 8(1):13245 pii:10.1038/s41598-018-31423-4.

As impacts of introduced species cascade through trophic levels, they can cause indirect and counter-intuitive effects. To investigate the impact of invasive species at the network scale, we use a generalized food web model, capable of propagating changes through networks with a series of ecologically realistic criteria. Using data from a small British offshore island, we quantify the impacts of four virtual invasive species (an insectivore, a herbivore, a carnivore and an omnivore whose diet is based on a rat) and explore which clusters of species react in similar ways. We find that the predictions for the impacts of invasive species are ecologically plausible, even in large networks. Species in the same taxonomic group are similarly impacted by a virtual invasive species. However, interesting differences within a given taxonomic group can occur. The results suggest that some native species may be at risk from a wider range of invasives than previously believed. The implications of these results for ecologists and land managers are discussed.

RevDate: 2018-09-05

Lopez-Vaamonde C, Sire L, Rasmussen B, et al (2018)

DNA barcodes reveal deeply neglected diversity and numerous invasions of micromoths in Madagascar.

Genome [Epub ahead of print].

Madagascar is a prime evolutionary hotspot globally, but its unique biodiversity is under threat, essentially from anthropogenic disturbance. There is a race against time to describe and protect the Madagascan endangered biota. Here we present a first molecular characterization of the micromoth fauna of Madagascar. We collected 1572 micromoths mainly using light traps in both natural and anthropogenically disturbed habitats in 24 localities across eastern and northwest Madagascar. We also collected 1384 specimens using a Malaise trap in a primary rain forest at Andasibe. In total, we DNA barcoded 2956 specimens belonging to 1537 BINs, 88.4% of which are new to BOLD. Only 1.7% of new BINs were assigned to species. Of 48 different families found, Dryadaulidae, Bucculatricidae, Bedelliidae, Batrachedridae and Blastobasidae are newly reported for Madagascar. The studied fauna shows highest affinity with the Afrotropics (146 BINs also occur in the African continent). We found 23 recognised pests or invasive species, mostly occurring in disturbed habitats. Malaise trap samples show high temporal turnover and alpha diversity with as many as 507 BINs collected; of these, astonishingly, 499 (98.4%) were novel to BOLD and 292 (57.6%) were singletons. Our results provide a baseline for future surveys across the island.

RevDate: 2018-09-05
CmpDate: 2018-09-05

Reilly SB, Wogan GOU, Stubbs AL, et al (2017)

Toxic toad invasion of Wallacea: A biodiversity hotspot characterized by extraordinary endemism.

Global change biology, 23(12):5029-5031.

(a) A map of Wallacea showing islands invaded by Duttaphrynus melanostictus in red, islands inhabited by Varanus komodoensis in blue, and localities of genetic samples in yellow points. (b) A D. melanostictus from Lombok Island. (c) Environmental niche model for the Sunda Islands clade of D. melanostictus projected into Wallacea. Green color indicates very high suitability, yellow color indicates high suitability, and orange color indicates moderate suitability.

RevDate: 2018-09-04

Meira A, Lopes-Lima M, Varandas S, et al (2018)

Invasive crayfishes as a threat to freshwater bivalves: Interspecific differences and conservation implications.

The Science of the total environment, 649:938-948 pii:S0048-9697(18)33312-6 [Epub ahead of print].

Freshwater bivalves have suffered major global declines, being the introduction of invasive alien species (IAS) an important, but not well studied, mechanism of threat. This study assessed the predator-prey relationship between two non-native crayfish species (Procambarus clarkii and Pacifastacus leniusculus) and three native (Anodonta anatina, Potomida littoralis and Unio delphinus) and one non-native (Corbicula fluminea) freshwater bivalve species through experiments in laboratory and validation under natural conditions (Sabor River basin, Portugal). All native bivalve species were preyed both in laboratory and in the field; however, both crayfish species were unable to prey C. fluminea. Predation was dependent on crayfish and bivalve species but was not affected neither by crayfish nor bivalve sizes. In the laboratory, the most preyed species by both crayfishes was A. anatina. On average, this species was preyed at least 12% more than other species, when crayfishes had a choice. Similar results were found in the field. We also found signs of competition between both crayfishes, being P. clarkii more dominant and aggressive as this species, on average, manipulated the bivalves 63.6% more times and 24:33 min longer than P. leniusculus, and initiated 55.8% more agnostic bouts. Our results support the idea that P. clarkii and P. leniusculus can affect native freshwater bivalves, but clear interspecific differences were detected. Both crayfishes may have direct and indirect impacts on bivalve populations by increasing mortality or by reducing their fitness. In addition, since both crayfishes do not prey C. fluminea, they offer this IAS another advantage over native bivalves. Given the widespread distribution of both P. clarkii and P. leniusculus and the threatened status of many freshwater bivalves, the dynamics and impacts of this relationship should be taken in account in the implementation of management measures devoted to the conservation of native freshwater bivalves.

RevDate: 2018-09-04

Leihy RI, Duffy GA, Nortje E, et al (2018)

High resolution temperature data for ecological research and management on the Southern Ocean Islands.

Scientific data, 5:180177 pii:sdata2018177.

Southern Ocean Islands are globally significant conservation areas. Predicting how their terrestrial ecosystems will respond to current and forecast climate change is essential for their management and requires high-quality temperature data at fine spatial resolutions. Existing datasets are inadequate for this purpose. Remote-sensed land surface temperature (LST) observations, such as those collected by satellite-mounted spectroradiometers, can provide high-resolution, spatially-continuous data for isolated locations. These methods require a clear sightline to measure surface conditions, however, which can leave large data-gaps in temperature time series. Using a spatio-temporal gap-filling method applied to high-resolution (~1 km) LST observations for 20 Southern Ocean Islands, we compiled a complete monthly temperature dataset for a 15-year period (2001-2015). We validated results using in situ measurements of microclimate temperature. Gap-filled temperature observations described the thermal heterogeneity of the region better than existing climatology datasets, particularly for islands with steep elevational gradients and strong prevailing winds. This dataset will be especially useful for terrestrial ecologists, conservation biologists, and for developing island-specific management and mitigation strategies for environmental change.

RevDate: 2018-09-04

Gollasch S, Hewitt CL, Bailey S, et al (2018)

Introductions and transfers of species by ballast water in the Adriatic Sea.

Marine pollution bulletin pii:S0025-326X(18)30626-X [Epub ahead of print].

Following the Editorial addressing the BALMAS project, we open the ballast water management special issue for the Adriatic Sea by providing background information on non-indigenous species and the mechanisms (vectors) of transport. Problems allocating introduction mechanisms for various species with certainty are described; in general, key introduction mechanisms are shipping, with ballast water and biofouling as dominant vectors, and aquaculture activities. The dominant mechanisms for introduction may differ through time, between regions and across species. We highlight ballast water as the focus of an international convention to prevent future introductions, reviewing management options and suggesting future research needs. This assessment is not restricted in application to the Adriatic Sea, but is applicable to other coastal waters. Results of such future work may contribute to the experience building phase planned by the International Maritime Organization for a harmonised implementation of the Ballast Water Management Convention.

RevDate: 2018-09-04
CmpDate: 2018-09-04

Arfin-Khan MAS, Vetter VMS, Reshi ZA, et al (2018)

Factors influencing seedling emergence of three global invaders in greenhouses representing major eco-regions of the world.

Plant biology (Stuttgart, Germany), 20(3):610-618.

Successful germination and seedling emergence in new environments are crucial first steps in the life history of global plant invaders and thus play a key role in processes of range expansion. We examined the germination and seedling emergence success of three global plant invaders - Lupinus polyphyllus, Senecio inaequidens and Verbascum thapsus - in greenhouses and climate chambers under climate regimes corresponding to seven eco-regions. Seed materials were collected from one non-native population for L. polyphyllus and S. inaequidens, and from 12 populations for V. thapsus (six natives and six non-natives). Experimental climates had significant effects on species responses. No species germinated in the dry (humidity ≤ 50%) and cool (≤ 5 °C) experimental climates. But all species germinated and emerged in two moderately cool (12-19 °C) and in three warm (24-27 °C) experimental climates. In general, V. thapsus showed higher fitness than S. inaequidens and L. polyphyllus. The climate of the seed source region influenced responses of native and non-native populations of V. thapsus. Non-native populations of V. thapsus, originating from the warmer seed source, showed higher performance in warm experimental climates and lower performance in moderately cool experimental climates compared to native populations. Responses of V. thapsus populations were also related to precipitation of the seed source region in moderately dry experimental climates. The warm, semi-arid and humid experimental climates are suitable for the crucial first steps of invasion success for L. polyphyllus, S. inaequidens and V. thapsus. The species adaptation to its source region modified the responses of our studied plants under different experimental climates representing major eco-regions of the world.

RevDate: 2018-09-04
CmpDate: 2018-09-04

Qi Y, Yan B, Fu G, et al (2017)

Germination of Seeds and Seedling Growth of Amaranthus retroflexus L. Following Sublethal Exposure of Parent Plants to Herbicides.

Scientific reports, 7(1):157 pii:10.1038/s41598-017-00153-4.

Herbicides have long-term effects on the vegetative parts and reproduction of plants; however, the carry-over effects of herbicides on the F1 generation of invasive plants remain unclear. The objectives of this work were to investigate the germination and growth of the F1 generation of A. retroflexus, an invasion plant, treated by sublethal herbicides. The results demonstrated that atrazine or tribenuron-methyl had carry-over effects on the F1 generation of A. retroflexus. Atrazine or tribenuron-methyl exposure during the vegetative and reproductive periods significantly inhibited the germination and growth of the F1 generation; a lower sublethal dose of atrazine or tribenuron-methyl did not weaken the inhibition of germination or growth of the F1 generation. Our results suggest that although herbicides have a carry-over inhibition effect on the F1 generation of invasive plants, they may have a more serious carry-over effect on native plants and cause changes in weed species composition and weed diversity.

RevDate: 2018-09-03

Kamgang B, Wilson-Bahun TA, Irving H, et al (2018)

Geographical distribution of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) and genetic diversity of invading population of Ae. albopictus in the Republic of the Congo.

Wellcome open research, 3:79.

Background: The arbovirus vector, Aedes albopictus, originating from Asia, has recently invaded African countries, including the Republic of the Congo, where it was associated with a chikungunya outbreak. Up until now, little was known about its distribution in relation to the native Aedes aegypti and how the invasion will modify the epidemiology of arboviral diseases. Here, we assessed the current distribution of Ae. albopictus and Ae. aegypti in the Republic of the Congo and explored the genetic diversity of the invading species, Ae. albopictus. Methods: Immature stages of Aedes were collected in nine locations in the Republic of the Congo in 2017 following a north-south transect and reared to adult stage. Adults were morphologically identified, counted and grouped according to species and location. Genetic diversity of Ae. albopictus was assessed by analyzing the cytochrome oxidase I (COI) gene. Results:Ae.albopictus and Ae. aegypti were found together across the country in all the locations investigated. The invasive species is predominant over the native species in all locations except Brazzaville, suggesting that Ae. albopictus is displacing Ae. aegypti across Congo. When comparing the species distributions across the two largest cities, Brazzaville and Pointe Noire, Ae. albopictus was more prevalent than Ae. aegypti in the suburbs whereas the opposite situation was reported in the city centre. Mitochondrial DNA analysis revealed very low genetic diversity of Ae. albopictus with only three haplotypes recorded across the country supporting the recent introduction of this species in the Republic of the Congo. Phylogenetic tree analysis revealed that Ae. albopictus from Congo originated from other tropical Asian countries such as China, likely as a result of increasing trade links. Conclusion: These findings are important for the implementation of vector control strategies and can serve as a foundation for further research on these vectors in the country.

RevDate: 2018-09-03
CmpDate: 2018-09-03

Robakowski P, Bielinis E, K Sendall (2018)

Light energy partitioning, photosynthetic efficiency and biomass allocation in invasive Prunus serotina and native Quercus petraea in relation to light environment, competition and allelopathy.

Journal of plant research, 131(3):505-523.

This study addressed whether competition under different light environments was reflected by changes in leaf absorbed light energy partitioning, photosynthetic efficiency, relative growth rate and biomass allocation in invasive and native competitors. Additionally, a potential allelopathic effect of mulching with invasive Prunus serotina leaves on native Quercus petraea growth and photosynthesis was tested. The effect of light environment on leaf absorbed light energy partitioning and photosynthetic characteristics was more pronounced than the effects of interspecific competition and allelopathy. The quantum yield of PSII of invasive P. serotina increased in the presence of a competitor, indicating a higher plasticity in energy partitioning for the invasive over the native Q. petraea, giving it a competitive advantage. The most striking difference between the two study species was the higher crown-level net CO2 assimilation rates (Acrown) of P. serotina compared with Q. petraea. At the juvenile life stage, higher relative growth rate and higher biomass allocation to foliage allowed P. serotina to absorb and use light energy for photosynthesis more efficiently than Q. petraea. Species-specific strategies of growth, biomass allocation, light energy partitioning and photosynthetic efficiency varied with the light environment and gave an advantage to the invader over its native competitor in competition for light. However, higher biomass allocation to roots in Q. petraea allows for greater belowground competition for water and nutrients as compared to P. serotina. This niche differentiation may compensate for the lower aboveground competitiveness of the native species and explain its ability to co-occur with the invasive competitor in natural forest settings.

RevDate: 2018-09-02

Shackleton RT, Larson BMH, Novoa A, et al (2018)

The human and social dimensions of invasion science and management.

Journal of environmental management pii:S0301-4797(18)30912-5 [Epub ahead of print].

Biological invasions are a leading cause of global environmental change given their effects on both humans and biodiversity. Humans introduce invasive alien species and may facilitate their establishment and spread, which can alter ecosystem services, livelihoods, and human well-being. People perceive the benefits and costs of these species through the lens of diverse value systems; these perspectives influence decisions about when and where to manage them. Despite the entanglement of humans with invasive alien species, most research on the topic has focused on their ecological aspects. Only relatively recently have the human and social dimensions of invasions started to receive sustained attention in light of their importance for understanding and governing biological invasions. This editorial draws on contributions to a special issue on the "Human and Social Dimensions of Invasion Science" and other literature to elucidate major trends and current contributions in this research area. We examine the relation between humans and biological invasions in terms of four crosscutting themes: (1) how people cause biological invasions; (2) how people conceptualise and perceive them; (3) how people are affected - both positively and negatively - by them; and (4) how people respond to them. We also highlight several ways in which research on the human and social dimensions of invasion science improves understanding, stakeholder engagement, and management.

RevDate: 2018-09-01

Gillings MR, Westoby M, TM Ghaly (2018)

Pollutants That Replicate: Xenogenetic DNAs.

Trends in microbiology pii:S0966-842X(18)30175-6 [Epub ahead of print].

Pollution is the dissemination of material that has harmful effects. Mobile DNA elements and antibiotic-resistance genes are being disseminated into the environment via human activity, and are increasingly being viewed as serious pollutants. These pollutants differ from conventional contaminants in important ways: they can replicate, and they can evolve.

RevDate: 2018-08-31

Rahel FJ, RL McLaughlin (2018)

Selective fragmentation and the management of fish movement across anthropogenic barriers.

Ecological applications : a publication of the Ecological Society of America [Epub ahead of print].

Disruption of movement patterns due to alterations in habitat connectivity is a pervasive effect of humans on animal populations. In many terrestrial and aquatic systems there is increasing tension between the need to simultaneously allow passage of some species while blocking the passage of other species. We explore the ecological basis for selective fragmentation of riverine systems where the need to restrict movements of invasive species conflicts with the need to allow passage of species of commercial, recreational, or conservation concern. We develop a trait-based framework for selective fish passage based on understanding the types of movements displayed by fishes and the role of ecological filters in determining the spatial distributions of fishes. We then synthesize information on trait-based mechanisms involved with these filters to create a multi-dimensional niche space based on attributes such as physical capabilities, body morphology, sensory capabilities, behavior, and movement phenology. Following this, we review how these mechanisms have been applied to achieve selective fish passage across anthropogenic barriers. To date, trap-and-sort or capture-translocation efforts provide the best options for movement filters that are completely species selective, but these methods are hampered by the continual, high cost of manual sorting. Other less effective methods of selective passage risk collateral damage in the form of lower or higher than desired levels of passage. Fruitful areas for future work include using combinations of ecological and behavioral traits to passively segregate species; using taxon-specific chemical or auditory cues to direct unwanted species away from passageways and into physical or ecological traps while attracting desirable species to passageways; and developing automated sorting mechanisms based on fish recognition systems. The trait-based approach proposed for fish could serve as a template for selective fragmentation in other ecological systems. This article is protected by copyright. All rights reserved.

RevDate: 2018-08-31

Hill MP, Binns M, Umina PA, et al (2018)

Climate, human influence and the distribution limits of the invasive European earwig, Forficula auricularia, in Australia.

Pest management science [Epub ahead of print].

BACKGROUND: By modelling species-environment relationships of pest species, it is possible to understand potential limits to their distributions when they invade new regions, and their likely continued spread. The European earwig, Forficula auricularia, is a non-native invasive species in Australia that has been in the country for over 170 years. However, in the last few decades it has invaded new areas. Unlike in other countries, F. auricularia is a pest species of grains production in Australia. In this study we detail the Australian distribution of this species, adding new samples focussed around grain-growing regions. Using this information, we build global species distribution models for F. auricularia to better understand species-environment relationships.

RESULTS: Our models indicate the distribution of F. auricularia is strongly associated with temperate through to semi-arid environments, a high winter rainfall and pronounced temperature seasonality. We identified regions that hold suitable, but as yet vacant, niche space for Australian populations, suggesting further potential for range expansion. Beyond climate, an index describing human influence on the landscape was important to understand the distribution limits of this pest. We identified regions where there was suitable climate space, but which F. auricularia has not occupied likely due to low levels of human impact.

CONCLUSION: Modelling the global distribution of a non-native pest species aided understanding of the regional distribution limits within Australia and highlighted the usefulness of human impact measures for modelling globally invasive insect species. This article is protected by copyright. All rights reserved.

RevDate: 2018-08-31

Eastwood G, Cunningham AA, Kramer LD, et al (2018)

The vector ecology of introduced Culex quinquefasciatus populations, and implications for future risk of West Nile virus emergence in the Galápagos archipelago.

Medical and veterinary entomology [Epub ahead of print].

Culex quinquefasciatus Say (Diptera: Culicidae), an important vector of West Nile virus (WNV) in the U.S.A., was first detected on the Galápagos Islands (Ecuador) in the 1980s. However, little is known of its ecology, distribution or capacity for arbovirus transmission in the Galápagos. We characterize details of lifecycle (including gonotrophic period), temporal abundance, spatial distribution, vector competence and host-feeding behaviour. Culex quinquefasciatus was detected on five islands of the Galápagos during 2006-2011. A period of 7-14 days was required for egg-adult emergence; water salinity above 5 ppt was demonstrated to hinder larval development. Blood-meal analysis indicated feeding on reptiles, birds and mammals. Assessment of WNV vector competency of Galápagos C. quinquefasciatus showed a median infectious dose of 7.41 log10 plaque-forming units per millilitre and evidence of vertical transmission (minimal filial infection rate of 3.7 per 1000 progeny). The distribution of C. quinquefasciatus across the archipelago could be limited by salt intolerance, and its abundance constrained by high temperatures. Feeding behaviour indicates potential to act as a bridge vector for transmission of pathogens across multiple taxa. Vertical transmission is a potential persistence mechanism for WNV on Galápagos. Together, our results can be used for epidemiological assessments of WNV and target vector control, should this pathogen reach the Galápagos Islands.

RevDate: 2018-08-31

Ancillotto L, Studer V, Howard T, et al (2018)

Environmental drivers of parasite load and species richness in introduced parakeets in an urban landscape.

Parasitology research pii:10.1007/s00436-018-6058-5 [Epub ahead of print].

Introduced species represent a threat to native wildlife worldwide, due to predation, competition, and disease transmission. Concurrent introduction of parasites may also add a new dimension of competition, i.e. parasite-mediated competition, through spillover and spillback dynamics. Urban areas are major hotspots of introduced species, but little is known about the effects of urban habitat structure on the parasite load and diversity of introduced species. Here, we investigated such environmental effects on the ectoparasite load, richness, and occurrence of spillback in two widespread invasive parakeets, Psittacula krameri and Myiopsitta monachus, in the metropolitan area of Rome, central Italy. We tested 231 parakeets and found that in both species parasite load was positively influenced by host abundance at local scale, while environmental features such as the amount of natural or urban habitats, as well as richness of native birds, influenced parasite occurrence, load, and richness differently in the two host species. Therefore, we highlight the importance of host population density and habitat composition in shaping the role of introduced parakeets in the spread of both native and introduced parasites, recommending the monitoring of urban populations of birds and their parasites to assess and manage the potential occurrence of parasite-mediated competition dynamics as well as potential spread of vector-borne diseases.

RevDate: 2018-08-31

Potgieter LJ, Gaertner M, Irlich UM, et al (2018)

Correction to: Managing Urban Plant Invasions: a Multi-Criteria Prioritization Approach.

The original version of the article unfortunately contained an error with the figure captions. The appropriate captions for Fig. 3-6 are published accordingly. The original article has been corrected.

RevDate: 2018-08-31

Carmosini N, Gillis R, Ismail A, et al (2018)

A Pilot Evaluation of the Toxicity of EarthTec® QZ on Invasive (Bithynia tentaculata) and Native (Physa gyrina) Snail Species from the Upper Mississippi River.

Bulletin of environmental contamination and toxicology pii:10.1007/s00128-018-2427-0 [Epub ahead of print].

We used a comparative approach to investigate the effects of a copper-based pesticide (EarthTec® QZ) on embryos of an invasive snail (Bithynia tentaculata) and a native snail (Physa gyrina). Embryos were exposed to one of three treatments: control (0 mg/L Cu2+), low-dose (0.1 mg/L Cu2+), or high-dose (0.6 mg/L Cu2+), which reflect manufacturer-recommended low and medium 4-day molluscicide treatment concentrations. Exposure to 0.6 mg/L Cu2+ over 4 days generated 100% mortality in both invasive and native snail embryos; however, reducing the exposure time from 4 to 1 day resulted in 100% mortality in B. tentaculata but some hatching (7%) in P. gyrina. In contrast, embryos of both species exposed to 0.1 mg/L Cu2+ treatment for 4 days showed almost 100% survivorship. Further manipulations of Cu2+ concentrations and exposure times may yield regimes that maximize mortality in B. tentaculata while minimizing negative impacts on native species.

RevDate: 2018-08-31

Jiang D, Chen S, Hao M, et al (2018)

Mapping the Potential Global Codling Moth (Cydia pomonella L.) Distribution Based on a Machine Learning Method.

Scientific reports, 8(1):13093 pii:10.1038/s41598-018-31478-3.

The spread of invasive species may pose great threats to the economy and ecology of a region. The codling moth (Cydia pomonella L.) is one of the 100 worst invasive alien species in the world and is the most destructive apple pest. The economic losses caused by codling moths are immeasurable. It is essential to understand the potential distribution of codling moths to reduce the risks of codling moth establishment. In this study, we adopted the Maxent (Maximum Entropy Model), a machine learning method to predict the potential global distribution of codling moths with global accessibility data, apple yield data, elevation data and 19 bioclimatic variables, considering the ecological characteristics and the spread channels that cover the processes from growth and survival to the dispersion of the codling moth. The results show that the areas that are suitable for codling moth are mainly distributed in Europe, Asia and North America, and these results strongly conformed with the currently known occurrence regions. In addition, global accessibility, mean temperature of the coldest quarter, precipitation of the driest month, annual mean temperature and apple yield were the most important environmental predictors associated with the global distribution of codling moths.

RevDate: 2018-08-30

Corlett RT (2016)

Plant diversity in a changing world: Status, trends, and conservation needs.

Plant diversity, 38(1):10-16 pii:S2468-2659(16)30030-0.

The conservation of plants has not generated the sense of urgency-or the funding-that drives the conservation of animals, although plants are far more important for us. There are an estimated 500,000 species of land plants (angiosperms, gymnosperms, ferns, lycophytes, and bryophytes), with diversity strongly concentrated in the humid tropics. Many species are still unknown to science. Perhaps a third of all land plants are at risk of extinction, including many that are undescribed, or are described but otherwise data deficient. There have been few known global extinctions so far, but many additional species have not been recorded recently and may be extinct. Although only a minority of plant species have a specific human use, many more play important roles in natural ecosystems and the services they provide, and rare species are more likely to have unusual traits that could be useful in the future. The major threats to plant diversity include habitat loss, fragmentation, and degradation, overexploitation, invasive species, pollution, and anthropogenic climate change. Conservation of plant diversity is a massive task if viewed globally, but the combination of a well-designed and well-managed protected area system and ex situ gap-filling and back-up should work anywhere. The most urgent needs are for the completion of the global botanical inventory and an assessment of the conservation status of the 94% of plant species not yet evaluated, so that both in and ex situ conservation can be targeted efficiently. Globally, the biggest conservation gap is in the hyperdiverse lowland tropics and this is where attention needs to be focused.

RevDate: 2018-08-30

Turkington R, WL Harrower (2016)

An experimental approach to addressing ecological questions related to the conservation of plant biodiversity in China.

Plant diversity, 38(1):2-9 pii:S2468-2659(16)30028-2.

We briefly introduce and describe seven questions related to community structure and biodiversity conservation that can be addressed using field experiments, and provide the context for using the vast geographic diversity, biodiversity, and network of Nature Reserves in China to perform these experiments. China is the world's third largest country, has a diverse topography, covers five climatic zones from cold-temperate to tropical, has 18 vegetation biomes ranging from Arctic/alpine tundra and desert to Tropical rain forest, and supports the richest biodiversity in the temperate northern hemisphere (>10% of the world total). But this tremendous natural resource is under relentless assault that threatens to destroy biodiversity and negatively impact the services ecosystems provide. In an attempt to prevent the loss of biodiversity, China has established 2729 nature reserves which cover 14.84% of the nation's area. Unfortunately underfunding, mismanagement, illegal activities, invasive species and global climate change threaten the effectiveness of these protected areas. Attention has focused on protecting species and their habitats before degradation and loss of either species or habitats occur. Here we argue that we must move beyond the simple protection of ecosystems, beyond their description, and by using experiments, try to understand how ecosystems work. This new understanding will allow us to design conservation programs, perform restoration of damaged or degraded areas, and address resource management concerns (e.g., agriculture, logging, mining, hunting) more effectively than with the current approach of ad hoc reactions to ecological and environmental problems. We argue that improving our understanding of nature can best be done using well designed, replicated, and typically manipulative field experiments.

RevDate: 2018-08-31
CmpDate: 2018-08-31

Brabec J, Scholz T, J Štefka (2018)

Development of polymorphic microsatellites for the invasive Asian fish tapeworm Schyzocotyle acheilognathi.

Parasitology international, 67(3):341-343.

We describe the development of ready-to-use set of fifteen polymorphic microsatellite markers to benefit future population biology and phylogeographic studies on the invasive Asian fish tapeworm Schyzocotyle acheilognathi. The microsatellite loci were selected from partial Illumina shotgun genome sequences of three parasite specimens and their universality tested on a set of 12 geographically distant populations of the parasite. Particularly low levels of heterozygosity have been detected in the Chinese population pointing towards possible hidden population structure that deserves further attention in future population genetic studies.

RevDate: 2018-08-30

Urakova N, Hall R, Strive T, et al (2018)

Restricted Host Specificity of Rabbit Hemorrhagic Disease Virus Is Supported by Challenge Experiments in Immune-compromised Mice (Mus musculus).

Journal of wildlife diseases [Epub ahead of print].

Rabbit hemorrhagic disease virus (RHDV) is a highly contagious calicivirus that causes peracute hemorrhagic fever and frequently kills rabbits before an effective adaptive immune response can be developed. In Australia and New Zealand, RHDV is employed to manage wild European rabbit (Oryctolagus cuniculus) populations. Although there is no evidence that RHDV replicates in animals other than lagomorphs, the detection of RHDV-specific antibodies and RHDV RNA in mice and other species has raised concerns about the host specificity of the virus. To investigate the replication potential of RHDV in mice (Mus musculus), standard laboratory mice and knockout animals that lack a functional interferon type I receptor were challenged with high doses of RHDV. None of the animals developed clinical signs of illness, and temporal quantification of the viral RNA by real-time PCR did not reveal signs of virus amplification. These data suggest that RHDV cannot replicate in mice-not even in animals with a severely compromised innate immune system.

RevDate: 2018-08-30

Lang PLM, Willems FM, Scheepens JF, et al (2018)

Using herbaria to study global environmental change.

The New phytologist [Epub ahead of print].

During the last centuries, humans have transformed global ecosystems. With their temporal dimension, herbaria provide the otherwise scarce long-term data crucial for tracking ecological and evolutionary changes over this period of intense global change. The sheer size of herbaria, together with their increasing digitization and the possibility of sequencing DNA from the preserved plant material, makes them invaluable resources for understanding ecological and evolutionary species' responses to global environmental change. Following the chronology of global change, we highlight how herbaria can inform about long-term effects on plants of at least four of the main drivers of global change: pollution, habitat change, climate change and invasive species. We summarize how herbarium specimens so far have been used in global change research, discuss future opportunities and challenges posed by the nature of these data, and advocate for an intensified use of these 'windows into the past' for global change research and beyond.

RevDate: 2018-08-30

Loureiro TG, Anastácio PM, Bueno SLS, et al (2018)

Management of invasive populations of the freshwater crayfish Procambarus clarkii (Decapoda, Cambaridae): test of a population-control method and proposal of a standard monitoring approach.

Environmental monitoring and assessment, 190(9):559 pii:10.1007/s10661-018-6942-6.

Invasive species are one of the main threats to biodiversity. When an alien species is introduced into a new environment, fast identification and definition of management strategies may avoid or minimize impacts. When an invasive species is already established, the most adopted approaches are population control and monitoring. In order to perform such strategies, assessment of characteristics of the invasive population is imperative. This study tested a new method of population size estimation and monitoring in an invasive population of crayfish Procambarus clarkii in a conservation area in the Atlantic Rain Forest (Southeastern Brazil). The population dynamics was studied for 1 year to examine the efficacy of the selected method and to evaluate if the population is stable. Later, the effect of periodical removal of animals on the population size was tested. The method of population estimation used in this study proved to be very effective. We recommend using it to monitor invasive populations of P. clarkii. The population size varied discretely over the year with variable but low growth rate, indicating that the population is already established which introduce a notable threat to native species. The continuous removal of specimens proved to be inefficient since the growth rate was higher after the removal. One intensive removal event might be more effective than a continuous moderate removal as the one applied in this study.

RevDate: 2018-08-30

Broadhurst L, D Coates (2017)

Plant conservation in Australia: Current directions and future challenges.

Plant diversity, 39(6):348-356 pii:S2468-2659(17)30078-1.

Australia is a large, old and flat island continent that became isolated following the breakup of the Gondwanan super continent. After more than 40-50 M years of independent evolution, approx. 600,000-700,000 species now call Australia home. More than 21,000 of these species are plants, with at least 84% of these being endemic. Plant taxa are protected, conserved and managed under a range of legislation at the State- and Territory-level as well as Federally for matters of national significance. This can create issues of misalignment among threatened species lists but generally there is co-operation among conservation agencies to reduce misalignments and to manage species irrespective of jurisdictional borders. Despite significant investment in programs designed to assist the recovery of Australian biodiversity, threatened plants in particular appear to be continuing to decline. This can be attributed to a range of factors including major threatening processes associated with habitat loss and invasive species, lack of public awareness of the cultural and socio-economic value of plant conservation, and our relatively poor understanding of basic species taxonomy and biology, especially for those species that have specific interactions with pollinators, symbionts and herbivores. A recent shift in Federally-based conservation programs has been to identify 30 key plant species for recovery through the setting of measurable targets, improving the support provided to recovery teams and encouraging industry, business and philanthropy to support conservation actions.

RevDate: 2018-08-30

Moser D, Lenzner B, Weigelt P, et al (2018)

Remoteness promotes biological invasions on islands worldwide.

Proceedings of the National Academy of Sciences of the United States of America pii:1804179115 [Epub ahead of print].

One of the best-known general patterns in island biogeography is the species-isolation relationship (SIR), a decrease in the number of native species with increasing island isolation that is linked to lower rates of natural dispersal and colonization on remote oceanic islands. However, during recent centuries, the anthropogenic introduction of alien species has increasingly gained importance and altered the composition and richness of island species pools. We analyzed a large dataset for alien and native plants, ants, reptiles, mammals, and birds on 257 (sub) tropical islands, and showed that, except for birds, the number of naturalized alien species increases with isolation for all taxa, a pattern that is opposite to the negative SIR of native species. We argue that the reversal of the SIR for alien species is driven by an increase in island invasibility due to reduced diversity and increased ecological naiveté of native biota on the more remote islands.

RevDate: 2018-08-30
CmpDate: 2018-08-30

Gruber J, Whiting MJ, Brown G, et al (2017)

The loneliness of the long-distance toad: invasion history and social attraction in cane toads (Rhinella marina).

Biology letters, 13(11):.

Individuals at the leading edge of a biological invasion constantly encounter novel environments. These pioneers may benefit from increased social attraction, because low population densities reduce competition and risks of pathogen transfer, and increase benefits of information transfer. In standardized trials, cane toads (Rhinella marina) from invasion-front populations approached conspecifics more often, and spent more time close to them, than did conspecifics from high-density, long-colonized populations.

RevDate: 2018-08-30
CmpDate: 2018-08-30

Miller AJ, Page RA, XE Bernal (2018)

Exploratory behavior of a native anuran species with high invasive potential.

Animal cognition, 21(1):55-65.

Exploratory behavior can be a key component of survival in novel or changing environments, ultimately determining population establishment. While many studies have investigated the behavior of wild animals in response to novel food items or objects, our understanding of how they explore novel environments is limited. Here, we examine how experience affects the foraging behavior of a species with high invasive potential. In particular, we investigate the movement and behavior of cane toads as a function of experience in a novel environment, and how the presence of food modulates exploration. Cane toads, from a population in their native range, were repeatedly tested in a large, naturalistic arena with or without food present. Both groups exhibited significant but different changes in exploratory behavior. While toads in an environment without food reduced exploratory behavior over trials, those with food present increased both food intake per trial and the directness of their paths to food, resulting in fewer approaches to food patches over time. Our results suggest that cane toads learn patch location and provide preliminary evidence suggesting toads use spatial memory, not associative learning, to locate food. In sum, we show that with experience, cane toads alter their behavior to increase foraging efficiency. This study emphasizes the role of learning in foraging in cane toads, a characteristic that may have facilitated their success as invaders.

RevDate: 2018-08-30
CmpDate: 2018-08-30

Hoyer IJ, Blosser EM, Acevedo C, et al (2017)

Mammal decline, linked to invasive Burmese python, shifts host use of vector mosquito towards reservoir hosts of a zoonotic disease.

Biology letters, 13(10):.

Invasive apex predators have profound impacts on natural communities, yet the consequences of these impacts on the transmission of zoonotic pathogens are unexplored. Collapse of large- and medium-sized mammal populations in the Florida Everglades has been linked to the invasive Burmese python, Python bivittatus Kuhl. We used historic and current data to investigate potential impacts of these community effects on contact between the reservoir hosts (certain rodents) and vectors of Everglades virus, a zoonotic mosquito-borne pathogen that circulates in southern Florida. The percentage of blood meals taken from the primary reservoir host, the hispid cotton rat, Sigmodon hispidus Say and Ord, increased dramatically (422.2%) from 1979 (14.7%) to 2016 (76.8%), while blood meals from deer, raccoons and opossums decreased by 98.2%, reflecting precipitous declines in relative abundance of these larger mammals, attributed to python predation. Overall species diversity of hosts detected in Culex cedecei blood meals from the Everglades declined by 40.2% over the same period (H(1979) = 1.68, H(2016) = 1.01). Predictions based upon the dilution effect theory suggest that increased relative feedings upon reservoir hosts translate into increased abundance of infectious vectors, and a corresponding upsurge of Everglades virus occurrence and risk of human exposure, although this was not tested in the current study. This work constitutes the first indication that an invasive predator can increase contact between vectors and reservoirs of a human pathogen and highlights unrecognized indirect impacts of invasive predators.

RevDate: 2018-08-30
CmpDate: 2018-08-30

Yang WY, Tang XT, Ju RT, et al (2017)

The population genetic structure of Corythucha ciliata (Say) (Hemiptera: Tingidae) provides insights into its distribution and invasiveness.

Scientific reports, 7(1):635 pii:10.1038/s41598-017-00279-5.

Corythucha ciliata (Say), an invasive pest originating from North America, causes severe damage on sycamore trees. However, little is known about the population genetics and evolutionary forces underlying the invasiveness of this important pest. In the present study, we use three mitochondrial genes (COI, ND1 and ND5) and nine microsatellite markers to investigate the population genetics of C. ciliata and retrace its spread through China. The results suggest a low level of genetic diversity in Chinese and European populations of C. ciliata. Our results indicate that populations of C. ciliata have obvious genetic structure, and genetic differentiation is not caused by geographic isolation. In median-joining networks, we observed a higher frequency of shared haplotypes in groups 1 and 3. Based on gene flow and approximate Bayesian computation analyses, we discovered that C. ciliata first invaded the east coast of China and subsequently moved inland. Demographic analysis suggested that populations of C. ciliata in China may have undergone a recent bottleneck effect. Finally, our results suggest that population structure, high gene flow and environmental conditions have favored the broad invasiveness of this important pest.

RevDate: 2018-08-29

Mahon AR, Horton DJ, Learman DR, et al (2018)

Investigating diversity of pathogenic microbes in commercial bait trade water.

PeerJ, 6:e5468 pii:5468.

The recreational bait trade is a potential pathway for pathogen introduction and spread when anglers dump bait shop sourced water into aquatic systems. Despite this possibility, and previous recognition of the importance of the bait trade in the spread of aquatic invasive species (AIS), to date there has been no region wide survey documenting pathogens in retail bait shops. In this study, we analyzed 96 environmental DNA samples from retail bait shops around the Great Lakes region to identify pathogens, targeting the V4 hypervariable region of the 16S rRNA gene. Additionally, we used samples from one site in Lake Michigan as a comparison to pathogen diversity and abundance in natural aquatic systems. Our results identified nine different groups of pathogens in the bait shop samples, including those that pose risks to both humans and fish species. Compared to wild sourced samples, the bait shops had higher relative abundance and greater taxonomic diversity. These findings suggest that the bait trade represents a potentially important pathway that could introduce and spread pathogens throughout the Great Lakes region. Improving pathogen screening and angler outreach should be used in combination to aid in preventing the future spread of high risk pathogens.

RevDate: 2018-08-28

Fogell DJ, Martin RO, Bunbury N, et al (2018)

Trade and conservation implications of new Beak and feather disease virus detection in native and introduced parrots.

Conservation biology : the journal of the Society for Conservation Biology [Epub ahead of print].

Psittacine beak and feather disease (PBFD), caused by Beak and feather disease virus (BFDV), has spread rapidly around the world, raising concerns for threatened species conservation and biosecurity associated with the global pet bird trade. The virus has been reported in several wild parrot populations, but data are lacking for many taxa and geographical areas with high parrot endemism. We aimed to advance understanding of BFDV distribution in many data-deficient areas and determine phylogenetic and biogeographic associations of the virus in 5 parrot species across Africa, the Indian Ocean islands, Asia, and Europe and focused specifically on the highly traded and invasive Psittacula krameri. Blood, feather, and tissue samples were screened for BFDV through standard polymerase chain reaction. Isolates obtained from positive individuals were then analyzed in a maximum likelihood phylogeny along with all other publically available global BFDV sequences. We detected BFDV in 8 countries where it was not known to occur previously, indicating the virus is more widely distributed than currently recognized. We documented for the first time the presence of BFDV in wild populations of P. krameri within its native range in Asia and Africa. We detected BFDV among introduced P. krameri on Mauritius and the Seychelles, raising concerns for island endemic species in the region. Phylogenetic relationships between viral sequences showed likely pathways of transmission between populations in southern Asia and western Africa, as well as between Seychelles and the United Kingdom. A high degree of phylogenetic relatedness between viral variants from geographically distant populations suggests recent introductions, likely driven by global trade. These findings highlight the need for effective regulation of international trade in live parrots, particularly in regions with high parrot endemism or vulnerable taxa where P. krameri could act as a reservoir host. This article is protected by copyright. All rights reserved.

RevDate: 2018-08-28

Heberling JM, Cassidy ST, Fridley JD, et al (2018)

Carbon gain phenologies of spring-flowering perennials in a deciduous forest indicate a novel niche for a widespread invader.

The New phytologist [Epub ahead of print].

Strategies of herbaceous species in deciduous forests are often characterized by the timing of life history phases (e.g. emergence, flowering, leaf senescence) relative to overstory tree canopy closure. Although springtime photosynthesis is assumed to account for the majority of their annual carbon budgets, the 12-month photosynthetic trajectories of forest herbs have not been quantified. We measured the temporal dynamics of carbon assimilation for seven native herbaceous perennials and the biennial Alliaria petiolata, a widespread invader in eastern North American forests. We assessed the relative importance of spring, summer, and autumn to species-level annual carbon budgets. Spring-emerging species showed significant variation in carbon assimilation patterns. High spring irradiance before canopy closure accounted for 39-100% of species-level annual carbon assimilation, but summer and autumn accounted for large proportions of some species' carbon budgets (up to 58% and 19%, respectively). Alliaria was phenologically unique, taking advantage both autumn and spring irradiance. Although spring-emerging understory species are often expected to rely on early-season irradiance, our results highlight interspecific differences and the importance of mid-late season carbon gain. Phenological strategies of forest herbs are a continuum rather than discrete categories, and invasive species may follow strategies that are underrepresented in the native flora.

RevDate: 2018-08-28

Poidatz J, Monceau K, Bonnard O, et al (2018)

Activity rhythm and action range of workers of the invasive hornet predator of honeybees Vespa velutina, measured by radio frequency identification tags.

Ecology and evolution, 8(15):7588-7598 pii:ECE34182.

In social insects, the activity rhythm of foragers and their action range determinate the activity of the colony. In vespids, which are mostly predators, the foraging range of workers determines their maximum predation pressure round the nest. One of these species, Vespa velutina, a recently invasive species introduced into Europe, exerts a strong predation on honeybees at the hive. Therefore, the definition of its activity rhythm and spatial range of predation is of primary importance. Using radio frequency identification tags (RFID), two experiments were carried out to (a) determine their return ability (called homing) in releasing 318 individuals at different distance from their colony and (b) monitor their foraging activity rhythm and the duration of their flights based on 71 individuals followed 24 hr/24 during 2 months. The homing ability of V. velutina was evaluated to be up to 5,000 m and was not affected by the cardinal orientation of release point. The lag time to return to the nest increased with the distance of release. Most of the flight activity took place between 07:00 a.m. and 08:00 p.m., hornets doing principally short flights of less than an hour. Foraging range was thus estimated ca. 1,000 m around the nest. This study of V. velutina assisted by RFID tags provides for the first time a baseline for its potential foraging distance that increase our knowledge of this species to (a) refine more accurately models for risk assessment and (b) define security perimeter for early detection of predation on invasion front.

RevDate: 2018-08-28

Montesinos D, RM Callaway (2018)

Traits correlate with invasive success more than plasticity: A comparison of three Centaurea congeners.

Ecology and evolution, 8(15):7378-7385 pii:ECE34080.

The importance of phenotypic plasticity for successful invasion by exotic plant species has been well studied, but with contradictory and inconclusive results. However, many previous studies focused on comparisons of native and invasive species that co-occur in a single invaded region, and thus on species with potentially very different evolutionary histories. We took a different approach by comparing three closely related Centaurea species: the highly invasive C. solstitialis, and the noninvasive but exotic C. calcitrapa and C. sulphurea. These species have overlapping distributions both in their native range of Spain and in their non-native range of California. We collected seeds from 3 to 10 populations from each region and species and grew them in common garden greenhouse conditions to obtain an F1 generation in order to reduce maternal effects. Then, F1 seeds were grown subjected to simulated herbivory, variation in nutrient availability, and competition, to explore plasticity in the responses to these conditions. We found little variation in phenotypic plasticity among species and regions, but C. solstitialis plants from California produced more biomass in competition than their Spanish conspecifics. This species also had the highest relative growth rates when in competition and when grown under low nutrient availability. Noninvasive congeners produced intermediate or opposite patterns.

RevDate: 2018-08-28

Carnegie AJ, GS Pegg (2018)

Lessons from the Incursion of Myrtle Rust in Australia.

Annual review of phytopathology, 56:457-478.

Austropuccinia psidii (myrtle rust) is a globally invasive neotropical rust of the Myrtaceae that came into international prominence following extensive damage to exotic Eucalyptus plantations in Brazil in the 1970s and 1980s. In 2005, myrtle rust established in Hawaii (USA), and over the past 12 years has spread from the Americas into Asia, the Pacific, and South Africa. Myrtle rust was detected in Australia in 2010, and the response and ultimately unsuccessful eradication attempt was a lesson to those concerned about the threat of exotic pests and diseases to Australia's environment. Seven years following establishment, we are already observing the decline of many myrtaceous species and severe impacts to native plant communities. However, the recently developed Myrtle rust in Australia draft action plan identified that there is no nationally coordinated response strategy for the environmental dimensions of this threat. Recent reviews have identified a greater need for involvement from environmental agencies in biosecurity preparedness, response, and resourcing, and we believe this approach needs to extend to the management of invasive environmental pathogens once they establish.

RevDate: 2018-08-27

de Oliveira Santos F, Rodrigues Teixeira B, Passos Cordeiro JL, et al (2018)

Expansion of the range of Necromys lasiurus (Lund, 1841) into open areas of the Atlantic Forest biome in Rio de Janeiro state, Brazil, and the role of the species as a host of the hantavirus.

Acta tropica pii:S0001-706X(18)30562-X [Epub ahead of print].

Necromys lasiurus is a generalist rodent that is thought to be the main reservoir of the Araraquara hantavirus, which causes Hantavirus Pulmonary Syndrome, in the Brazilian Cerrado savanna. This species occurs naturally in the open habitats of the Cerrado, Pantanal and Caatinga biomes, where it often occurs at high densities, although the distribution of the species has recently been observed expanding into the Brazilian state of Rio de Janeiro. This study aimed to map the occurrence of N. lasiurus within the Atlantic Forest of Rio de Janeiro state and discuss the potential role of the species as a reservoir of the Araraquara hantavirus in these areas. The study was based on a comprehensive literature search and four expeditions for the collection of specimens in the state of Rio de Janeiro. The data were used to predict the distribution of N. lasiurus, confirm the distribution of the species in the state, and detect the rates of hantavirus infection in these rodents. Necromys lasiurus has been recorded at 16 localities in 10 municipalities of Rio de Janeiro state. The relative abundance of N. lasiurus was low at all localities, except for the REBIO Poço das Antas and APA-BRSJ, two protected areas. Necromys lasiurus was associated primarily with landscapes dominated by farmland (plantations or pasture) at relatively low altitudes in the vicinity of bodies of water. A total of 204 serum samples were collected, but none were reactive for hantavirus. The distribution of N. lasiurus is expanding into many areas of the anthropogenic matrix, but it is not usually either abundant or dominant in these areas. The relatively reduced abundance of N. lasiurus in Rio de Janeiro and the lack of infection in all the areas investigated indicate that it is unlikely to be a reservoir of hantavirus in this region in the near future.

RevDate: 2018-08-27
CmpDate: 2018-08-27

Vasil'ev AG, Bol'shakov VN, Vasil'eva IA, et al (2018)

Morphogenetic Effects of Resettlement of Mole Voles (Ellobius talpinus Pall., 1770) from the Southern Population to the Northern Boundary of the Species Range.

Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 478(1):26-28.

Geometric morphometry has been used to reveal transformations of mandible morphogenesis in the offspring of mole voles resettled to the northern part of the species range from a southern population. The transformations were new compared to both the original (southern) and the aboriginal (northern) populations. A significant increase in the intragroup morphological disparity estimated by the mean nearest neighbor distance (MNND) in the resettled animals compared to both aboriginal populations is an indirect indication of an increased developmental instability in the resettled animals exposed to new climatic conditions.

RevDate: 2018-08-27
CmpDate: 2018-08-27

McCreless EE, Huff DD, Croll DA, et al (2016)

Past and estimated future impact of invasive alien mammals on insular threatened vertebrate populations.

Nature communications, 7:12488 pii:ncomms12488.

Invasive mammals on islands pose severe, ongoing threats to global biodiversity. However, the severity of threats from different mammals, and the role of interacting biotic and abiotic factors in driving extinctions, remain poorly understood at a global scale. Here we model global extirpation patterns for island populations of threatened and extinct vertebrates. Extirpations are driven by interacting factors including invasive rats, cats, pigs, mustelids and mongooses, native species taxonomic class and volancy, island size, precipitation and human presence. We show that controlling or eradicating the relevant invasive mammals could prevent 41-75% of predicted future extirpations. The magnitude of benefits varies across species and environments; for example, managing invasive mammals on small, dry islands could halve the extirpation risk for highly threatened birds and mammals, while doing so on large, wet islands may have little benefit. Our results provide quantitative estimates of conservation benefits and, when combined with costs in a return-on-investment framework, can guide efficient conservation strategies.

RevDate: 2018-08-26

Kuhlisch C, Kampen H, D Walther (2018)

The Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) in Central Germany: Surveillance in its northernmost distribution area.

Acta tropica pii:S0001-706X(18)30649-1 [Epub ahead of print].

The invasive Asian tiger mosquito Aedes albopictus has recently been observed in southern Germany for the first time to reproduce and even overwinter north of the Alps. After the accidental capture of adult specimens in Jena, German federal state of Thuringia, in mid-2015, regular inspections brought forth developmental stages until autumn 2015, indicating local reproduction. Surveillance activities implemented in 2016 showed larvae already in early May, suggesting overwintering, and throughout the season until late October, although population densities remained low. Further sporadic specimens found in 2017 argue for establishment. Jena is located in Central Germany, north of all known distribution areas of Ae. albopictus, with the area of the municipality affected by the tiger mosquito characterised by a relatively mild climate. To check the suitability of the local climate for Ae. albopictus, winter temperatures, measured in a cemetery of Jena where larvae had regularly been found in 2015 and 2016, were analysed and compared with two sites of establishment in southern Germany. The conditions were similar at all three locations, suggesting that the Jena population might also be able to survive in the long term. While the municipality authorities have been informed and education of the Jena citizens to avoid producing potential breeding places has started, insecticidal control has not yet been implemented.

RevDate: 2018-08-25

Villatoro FJ, Naughton-Treves L, Sepúlveda MA, et al (2018)

When free-ranging dogs threaten wildlife: Public attitudes toward management strategies in southern Chile.

Journal of environmental management pii:S0301-4797(18)30677-7 [Epub ahead of print].

Free-ranging dogs (Canis familiaris) significantly threaten wildlife, including endangered species. Although this problem resembles threats from other invasive animals, managing roaming dogs is even more fraught due to their close association with humans. Here we use interviews (n = 166) to document patterns of dog ownership and care and to measure public attitudes toward management strategies to control free-roaming dogs that threaten wildlife in rural areas of southern Chile. We compare attitudes toward lethal control and fines in scenarios where dogs attack livestock, children or wild animals or enter protected areas. We also test for variation in attitudes according to gender, age, education and proximity to urban areas. Most respondents (98.1%) opposed lethal control for at least one scenario and they were more likely to accept killing dogs that attacked sheep than those attacking wildlife. Similarly, support for fines was higher when dogs attacked livestock or people versus wild animals. Respondents consistently favored fining the owner over eliminating the problem dog. When asked about their management preferences, many respondents indicated that the movement of problem dogs-including to a lesser extent those threatening wildlife-should be restricted. However, in practice most dog-owners allowed one or more of their dogs to move freely at least part of the time. Finally, the wildlife species of concern mattered, e.g. 40% thought no action was necessary when dogs attack foxes, but this dropped to 12% for pudu (a small deer). In sum, participants had significantly more concern for livestock and human safety than for wildlife protection. We close by discussing management and policy implications.

RevDate: 2018-08-25

Martínez-Sanz M, Erboz E, Fontes C, et al (2018)

Valorization of Arundo donax for the production of high performance lignocellulosic films.

Carbohydrate polymers, 199:276-285.

This work reports on the valorization of the biomass from the aquatic invasive species Arundo donax for the extraction of lignocellulosic fractions and the development of films with interest in food packaging. Stems and leaves were separately evaluated, with the stems producing higher yields and better properties for the extracted fractions. The purification of cellulose by removing hemicelluloses led to more crystalline and thermally stable fractions, which were more homogeneously dispersed in water and produced films with enhanced transparency, mechanical and water barrier properties. The application of a simplified extraction protocol, avoiding the use of organic solvents, led to the presence of minor amounts of lipidic impurities in the fractions, which, surprisingly, had a positive impact in the properties of the films. In particular, the film obtained from the purified cellulose without Soxhlet treatment (F3A) outperforms biopolymeric materials such as starch and PLA in terms of mechanical and water barrier performance.

RevDate: 2018-08-24

Koske RE, JN Gemma (1990)


American journal of botany, 77(4):466-474.

Vesicular-arbuscular mycorrhizal fungi (VAMF) were a nearly constant component of the coastal strand of the Hawaiian Islands, occurring in beach sand, driftline debris, in roots of 23 of 31 species of vascular plants examined, and in association with rhizomes of two native species, Sporobolus virginicus and Jacquemontia sandwicensis. Mycorrhizae were most frequent and intensity of VAM development was greatest in endemic plants, less in indigenous species, and least in alien species. Spores of VAMF were produced in abundance between the rhizome and the leaf sheaths of Sporobolus. Roots of two strand species, including roots of Sporobolus that were immersed in seawater for 7 days, functioned as inocula of VAMF in pot-culture studies. The close association between propagules of VAMF and vegetative fragments of indigenous plants found in the present study suggests a mechanism of codispersal that appears to ensure the maintenance of the symbiosis in nutrient-deficient sites where it is most beneficial. The codispersal of fungus and plant may explain the high frequency of mycotrophy in strand species in the tropical Pacific.

RevDate: 2018-08-24

Andersen MC (1992)


American journal of botany, 79(10):1087-1091.

Dispersal is an important life history component. Seed settling velocity may be a useful surrogate for the measurement of dispersal ability in wind-dispersed plants, particularly those whose seeds have plumose dispersal structures. I measured settling velocities on seeds of eight species of Asteraceae, including annuals, biennials, and perennials, and including both native and introduced species. The species are Aster exilis, Picris echioides, Chrysopsis villosa, Heterotheca grandiflora, Conyza bonariensis, Sonchus oleraceous, Senecio vulgaris, and Taraxacum officinale. From these data I estimated components of total variation in seed settling velocities due to differences among species, among plants within species, and among inflorescences and seeds within plants. Significant amounts of variability were found at all levels. Contrasts among mean settling velocities showed that the five introduced species have lower settling velocities than the three native species; this result continues to be true when annuals are considered separately from biennials and perennials. Also, over all eight species, annuals have lower settling velocities than biennials and perennials. Variability among species apparently reflects different dispersal "strategies" employed by the species; these different strategies may be correlated with other life-history traits and with ecological characteristics. Variability within species also may have ecological consequences in that such variability may represent an example of risk-spreading.

RevDate: 2018-08-24

Chen S, Chen H, Y Xu (2018)

Safe Chemical Repellents to Prevent the Spread of Invasive Ants.

Pest management science [Epub ahead of print].

BACKGROUND: The red imported fire ant, Solenopsis invicta, is one of the most dangerous invasive species in the world. Fire ants can spread by hiding among plant materials and soil that are transported from infested areas in vehicles and vessels. Therefore, efficient repellents may be used to prevent fire ants from infesting transported goods. Though some fire ant repellants have been identified, novel, cost-effective, and environmentally friendly materials for fire ant control are still needed. Recent studies with other model insects have suggested readily available, non-toxic alternatives (e.g., anthranilates) to commercial repellents.

RESULTS: In the present study, we measured the repellent effects of the food additives ethyl anthranilate and butyl anthranilate against nesting by fire ant workers, and the results demonstrated that extremely low concentrations of these compounds can prevent fire ant nesting in pots. The tested compounds remained active at concentrations below 100 μl/L, which is many times lower than the minimum active concentration of any other proposed compound, including the established insect repellent DEET.

CONCLUSION: These inexpensive chemicals are safely used by the food and cosmetics industries, and their high efficiency differentiated them as the most promising chemicals for use in preventing the spread of fire ants; thus, these chemicals should be evaluated for further potential applications. This article is protected by copyright. All rights reserved.

RevDate: 2018-08-23

Kumar A, Pandeya A, Malik G, et al (2018)

---A web resource for nutrient use efficiency-related genes, quantitative trait loci and microRNAs in important cereals and model plants.

F1000Research, 7:.

Cereals are key contributors to global food security. Genes involved in the uptake (transport), assimilation and utilization of macro- and micronutrients are responsible for the presence of these nutrients in grain and straw. Although many genomic databases for cereals are available, there is currently no cohesive web resource of manually curated nutrient use efficiency (NtUE)-related genes and quantitative trait loci (QTLs). In this study, we present a web-resource containing information on NtUE-related genes/QTLs and the corresponding available microRNAs for some of these genes in four major cereal crops (wheat (Triticum aestivum), rice (Oryza sativa), maize (Zea mays), barley (Hordeum vulgare)), two alien species related to wheat (Triticum urartu and Aegilops tauschii), and two model species (Brachypodium distachyon and Arabidopsis thaliana). Gene annotations integrated in the current web resource were manually curated from the existing databases and the available literature. The primary goal of developing this web resource is to provide descriptions of the NtUE-related genes and their functional annotation. MicroRNAs targeting some of the NtUE related genes and the QTLs for NtUE-related traits are also included. The genomic information embedded in the web resource should help users to search for the desired information.

RevDate: 2018-08-23

Banks PB, Carthey AJR, JP Bytheway (2018)

Australian native mammals recognize and respond to alien predators: a meta-analysis.

Proceedings. Biological sciences, 285(1885): pii:rspb.2018.0857.

Prey naiveté is a failure to recognize novel predators and thought to cause exaggerated impacts of alien predators on native wildlife. Yet there is equivocal evidence in the literature for native prey naiveté towards aliens. To address this, we conducted a meta-analysis of Australian mammal responses to native and alien predators. Australia has the world's worst record of extinction and declines of native mammals, largely owing to two alien predators introduced more than 150 years ago: the feral cat, Felis catus, and European red fox, Vulpes vulpes Analysis of 94 responses to predator cues shows that Australian mammals consistently recognize alien foxes as a predation threat, possibly because of thousands of years of experience with another canid predator, the dingo, Canis lupus dingo We also found recognition responses towards cats; however, in four of the seven studies available, these responses were of risk-taking behaviour rather than antipredator behaviour. Our results suggest that a simple failure to recognize alien predators is not behind the ongoing exaggerated impacts of alien predators in Australia. Instead, our results highlight an urgent need to better understand the appropriateness of antipredator responses in prey towards alien predators in order to understand native prey vulnerability.

RevDate: 2018-08-22

Wells K, Fordham DA, Brook BW, et al (2018)

Disentangling synergistic disease dynamics: Implications for the viral biocontrol of rabbits.

The Journal of animal ecology, 87(5):1418-1428.

European rabbits (Oryctolagus cuniculus) have been exposed to rabbit haemorrhagic disease virus (RHDV) and myxoma virus (MYXV) in their native and invasive ranges for decades. Yet, the long-term effects of these viruses on rabbit population dynamics remain poorly understood. In this context, we analysed 17 years of detailed capture-mark-recapture data (2000-2016) from Turretfield, South Australia, using a probabilistic state-space hierarchical modelling framework to estimate rabbit survival and epidemiological dynamics. While RHDV infection and disease-induced death were most prominent during annual epidemics in winter and spring, we found evidence for continuous infection of susceptible individuals with RHDV throughout the year. RHDV-susceptible rabbits had, on average, 25% lower monthly survival rates compared to immune individuals, while the average monthly force of infection in winter and spring was ~38%. These combined to result in an average infection-induced mortality rate of 69% in winter and spring. Individuals susceptible to MYXV and immune to RHDV had similar survival probabilities to those having survived infections from both viruses, whereas individuals susceptible to both RHDV and MYXV had higher survival probabilities than those susceptible to RHDV and immune to MYXV. This suggests that MYXV may reduce the future survival rates of individuals that endure initial MYXV infection. There was no evidence for long-term changes in disease-induced mortality and infection rates for either RHDV or MYXV. We conclude that continuous, year-round virus perpetuation (and perhaps heterogeneity in modes of transmission and infectious doses during and after epidemics) acts to reduce the efficiency of RHDV and MYXV as biocontrol agents of rabbits in their invasive range. However, if virulence can be maintained as relatively constant through time, RHDV and MYXV will likely continue realizing strong benefits as biocontrol agents.

RevDate: 2018-08-22

Junaedi DI, McCarthy MA, Guillera-Arroita G, et al (2018)

Traits influence detection of exotic plant species in tropical forests.

PloS one, 13(8):e0202254 pii:PONE-D-17-24228.

Detecting exotic plant species is essential for invasive species management. By accounting for factors likely to affect species' detection rates (e.g. survey conditions, observer experience), detectability models can help choose search methods and allocate search effort. Integrating information on species' traits can refine detectability models, and might be particularly valuable if these traits can help improve estimates of detectability where data on particular species are rare. Analysing data collected during line transect distance sampling surveys in Indonesia, we used a multi-species hierarchical distance sampling model to evaluate how plant height, leaf size, leaf shape, and survey location influenced plant species detectability in secondary tropical rainforests. Detectability of the exotic plant species increased with plant height and leaf size. Detectability varied among the different survey locations. We failed to detect a clear effect of leaf shape on detectability. This study indicates that information on traits might improve predictions about exotic species detection, which can then be used to optimise the allocation of search effort for efficient species management. The innovation of the study lies in the multi-species distance sampling model, where the distance-detection function depends on leaf traits and height. The method can be applied elsewhere, including for different traits that may be relevant in other contexts. Trait-based multispecies distance sampling can be a practical approach for sampling exotic shrubs, herbs, or grasses species in the understorey of tropical forests.

RevDate: 2018-08-22

Weickardt I, Zehnsdorf A, W Durka (2018)

Development and characterization of simple sequence repeat markers for the invasive tetraploid waterweed Elodea nuttallii (Hydrocharitaceae).

Applications in plant sciences, 6(4):e1146 pii:APS31146.

Premise of the Study: To enhance the understanding of the recent invasion process of the clonal waterweed Elodea nuttallii (Hydrocharitaceae), analyses of population structure and genotypic diversity need to be undertaken, for which genetic markers are needed.

Methods and Results: High-throughput sequencing of DNA enriched for microsatellites was used to develop 24 loci that were characterized in E. nuttallii, 21 of which were polymorphic, with the number of alleles ranging from two to 10. In two populations, expected heterozygosity ranged among loci between zero and 0.796. In the congener E. canadensis, all markers yielded PCR products, 19 of which were polymorphic, with two to nine alleles and expected heterozygosity ranging from zero to 0.690 in two populations.

Conclusions: The markers described should be useful for future studies of population structure and clonal diversity of E. nuttallii as well as E. canadensis in their native and invasive range.

RevDate: 2018-08-21

Coetzee BWT, SL Chown (2016)

Land-use change promotes avian diversity at the expense of species with unique traits.

Ecology and evolution, 6(21):7610-7622 pii:ECE32389.

Land-use change may alter both species diversity and species functional diversity patterns. To test the idea that species diversity and functional diversity changes respond in differing ways to land-use changes, we characterize the form of the change in bird assemblages and species functional traits along an intensifying gradient of land use in the savanna biome in a historically homogeneous vegetation type in Phalaborwa, South Africa. A section of this vegetation type has been untransformed, and the remainder is now mainly characterized by urban and subsistence agricultural areas. Using morphometric, foraging and breeding functional traits of birds, we estimate functional diversity changes. Bird species richness and abundance are generally higher in urban and subsistence agricultural land uses, as well as in the habitat matrix connecting these regions, than in the untransformed area, a pattern mainly driven through species replacement. Functionally unique species, particularly ground nesters of large body size, were, however, less abundant in more utilized land uses. For a previously homogenous vegetation type, declines in the seasonality of energy availability under land-use change have led to an increase in local avian diversity, promoting the turnover of species, but reduced the abundance of functionally unique species. Although there is no simple relationship between land-use and diversity change, land-use change may suit some species, but such change may also involve functional homogenization.

RevDate: 2018-08-21

Xu M, Lu Z, Lu YY, et al (2018)

Cuticular hydrocarbon chemistry, an important factor shaping the current distribution pattern of the imported fire ants in the USA.

Journal of insect physiology pii:S0022-1910(18)30160-4 [Epub ahead of print].

Two sibling species, Solenopsis richteri and S. invicta, were both introduced into the southern USA from South America in the early 20th century. Today, S. richteri occupies higher latitudes and colder areas, while S. invicta occupies lower latitudes. Between the distributions of the two species, there is a large area of viable hybrid (S. richteri × S. invicta) populations. This study aimed to characterize the forces driving this distribution pattern and the underlying mechanisms. Cuticular hydrocarbons (CHCs) of freshly killed workers of S. invicta, hybrids, and S. richteri were removed using hexane. Both intact and CHCs-extracted workers were subjected to a constant rate of increasing temperature from 10 to 60 °C to obtain relative water loss and the water loss transition temperature (Tc-ant). Mass loss and Tc-ant were both significantly increased with CHCs removal. We then examined the CHC composition of three species. CHC profiles of S. richteri are characterized by significant amounts of short-chain (C23-C27) saturated and unsaturated hydrocarbons. In contrast, profiles of S. invicta consist primarily of long-chain (C27-C29) saturated hydrocarbons; unsaturated alkenes are completely lacking. Hybrid fire ants show intermediate profiles of the two parent species. We measured the melting point (Tm) and water-loss transition temperature of CHC blends (Tc-CHC) of different ant species colonies using differential scanning calorimetry (DSC) and an artificial membrane system, respectively. There were 3-5 Tms of each CHCs sample of different ant colonies due to their complex chemistry. The highest Tms (Tm-maxs) of CHCs samples from S. invicta and the hybrid were significantly higher than that from S. richteri. The correlation between Tc-CHC and Tm-max obtained from the same CHCs sample was highly significant. These results reveal that species having higher Tc and Tm-max retain more water under relatively higher temperature, and consequently are able to occupy warmer environments. We conclude that CHC chemistry plays a role in shaping current distribution patterns of S. richteri, S. invicta and their hybrid in the United States.

RevDate: 2018-08-21

Grupe AC, Sulzbacher MA, Grebenc T, et al (2018)

Tuber brennemanii and Tuber floridanum: Two new Tuber species are among the most commonly detected ectomycorrhizal taxa within commercial pecan (Carya illinoinensis) orchards.

Mycologia [Epub ahead of print].

Truffles are sequestrate hypogeous fungi, and most form ectomycorrhizal (ECM) associations with trees. Truffles belonging to the genus Tuber (Pezizales, Ascomycota), "true truffles," associate with diverse plant hosts, including economically important species such as pecan (Carya illinoinensis). Morphological and phylogenetic studies delimited several major lineages of Tuber, which include many cryptic and undescribed species. One of these, the Maculatum clade, is a speciose group characterized by relatively small, light-colored ascomata that have alveolate-reticulate spores. Here, we describe two new species in the Maculatum clade, Tuber brennemanii and T. floridanum (previously identified as Tuber sp. 36 and Tuber sp. 47). We delineate these two species by phylogenetic analyses of nuc ITS1-5.8S-ITS2 (= ITS) and partial 28S rDNA (= LSU), and through morphological analysis. A recent collection of T. floridanum from a pecan orchard in Brazil indicates that this species was introduced there on the roots of pecan seedlings. Systematic studies of ascomata and ECM fungal communities indicate that these species are geographically widespread and common ECM symbionts of pecans and other members of the Fagales, particularly in sites with disturbed soils and nutrient enrichment.

RevDate: 2018-08-21

Hudson DM, Sexton DJ, Wint D, et al (2018)

Physiological and behavioral response of the Asian shore crab, Hemigrapsus sanguineus, to salinity: implications for estuarine distribution and invasion.

PeerJ, 6:e5446 pii:5446.

The invasive Asian shore crab, Hemigrapsus sanguineus, is ubiquitous in the rocky intertidal zone of the western North Atlantic. A likely contributor to this colonization is that H. sanguineus is able to handle a wide range of salinities, and is thus more likely to spread through a greater geographic area of estuaries. This study investigated the salinity effects on this animal by observing survival across a range of salinities, the maintenance of hemolymph osmolality under different salinities, and behavioral preference for and avoidance of salinities. H. sanguineus showed high survival across a broad range of salinities, had little change in hemolymph osmolality over a short-term salinity shock, and behaviorally distinguished between salinities when presented with a choice, under both acclimation salinities of 5 PSU or 35 PSU. Such results suggest H. sanguineus has a hardiness for the rapid changes in salinity that happen in the intertidal zone, yet is capable of physically moving to a more optimal salinity. This enhances their competitiveness as an invader, particularly surviving lower salinities that present challenges during high-precipitation events in rocky intertidal areas, and partially explains this species' dominance in this habitat type.

RevDate: 2018-08-21

Sánchez-Blanco J, Vega-Peña EV, FJ Espinosa-García (2018)

Darwin's naturalization hypothesis does not explain the spread of nonnative weed species naturalized in México.

PeerJ, 6:e5444 pii:5444.

Background: Despite numerous tests of Darwin's naturalization hypothesis (DNH) evidence for its support or rejection is still contradictory. We tested a DNH derived prediction stating that nonnative species (NNS) without native congeneric relatives (NCR) will spread to a greater number of localities than species with close relatives in the new range. This test controlled the effect of residence time (Rt) on the spread of NNS and used naturalized species beyond their lag phase to avoid the effect of stochastic events in the establishment and the lag phases that could obscure the NCR effects on NNS.

Methods: We compared the number of localities (spread) occupied by NNS with and without NCR using 13,977 herbarium records for 305 NNS of weeds. We regressed the number of localities occupied by NNS versus Rt to determine the effect of time on the spread of NNS. Then, we selected the species with Rt greater than the expected span of the lag phase, whose residuals were above and below the regression confidence limits; these NNS were classified as widespread (those occupying more localities than expected by Rt) and limited-spread (those occupying fewer localities than expected). These sets were again subclassified into two groups: NNS with and without NCR at the genus level. The number of NNS with and without NCR was compared using χ2 tests and Spearman correlations between the residuals and the number of relatives. Then, we grouped the NNS using 34 biological attributes and five usages to identify the groups' possible associations with spread and to test DNH. To identify species groups, we performed a nonmetric multidimensional scaling (NMDS) analysis and evaluated the influences of the number of relatives, localities, herbarium specimens, Rt, and residuals of regression. The Spearman correlation and the Mann-Whitney U test were used to determine if the DNH prediction was met. Additionally, we used the clustering objects on subsets of attributes (COSA) method to identify possible syndromes (sets of biological attributes and usages) associated to four groups of NNS useful to test DNH (those with and without NCR and those in more and fewer localities than expected by Rt).

Results: Residence time explained 33% of the variation in localities occupied by nonnative trees and shrubs and 46% of the variation for herbs and subshrubs. The residuals of the regression for NNS were not associated with the number or presence of NCR. In each of the NMDS groups, the number of localities occupied by NNS with and without NCR did not significantly differ. The COSA analysis detected that only NNS with NCR in more and fewer localities than expected share biological attributes and usages, but they differ in their relative importance.

Discussion: Our results suggest that DNH does not explain the spread of naturalized species in a highly heterogeneous country. Thus, the presence of NCR is not a useful characteristic in risk analyses for naturalized NNS.

RevDate: 2018-08-21

Potocka M, E Krzemińska (2018)

Trichocera maculipennis (Diptera)-an invasive species in Maritime Antarctica.

PeerJ, 6:e5408 pii:5408.

Antarctica, with its severe conditions, is poor in terrestrial fauna species. However, an increase in human presence together with climate change may cause an influx of non-native species. Here we report a significant increase in colonized area of one of the few known invasive species to date in Antarctica. Non-native flies of Trichocera maculipennis have been recently observed in the Admiralty Bay area on King George Island, South Shetlands Islands, West Antarctica, 10 years after its first record in Maritime Antarctica (Maxwell Bay, King George Island). Its rapid spread across the island, despite geographic barriers such as glaciers, indicates successful adaptation to local environmental conditions and suggests this species is invasive. The mode of life of T. maculipennis, observed in natural and anthropogenous habitat and in laboratory conditions, is reported. The following adaptations enabled its invasion and existence within the sewage system in Antarctic scientific stations: the ability to survive in complete darkness, male ability to mate on the substrate surface without prior swarming in flight, and adaptation of terrestrial larvae to survive in semi-liquid food. Possible routes of introduction to Antarctica and between two bays on King George Island are discussed, as well as further research leading to the containment and eradication of this species.

RevDate: 2018-08-21

Bower DS, Yasumiba K, Trumbo DR, et al (2018)

Spinal arthritis in cane toads across the Australian landscape.

Scientific reports, 8(1):12458 pii:10.1038/s41598-018-30099-0.

Loss of fitness can be a consequence of selection for rapid dispersal ability in invasive species. Increased prevalence of spinal arthritis may occur in cane toad populations at the invasion front as a cost of increased invasiveness, but our knowledge of the ecological drivers of this condition is lacking. We aimed to determine the factors explaining the prevalence of spinal arthritis in populations across the Australian landscape. We studied populations across a gradient of invasion histories. We collected 2415 toads over five years and determined the presence and size of spondylosis for each individual. We examined the effect of host size, leg length and invasion history on the prevalence of spondylosis. Host size was a significant predictor of spondylosis across populations. Contrary to our expectation, the overall prevalence of spondylosis was not positively related to invasion history and did not correlate with toad relative leg length. Rather than invasion age, the latitude at which populations were sampled provided an alternate explanation for the prevalence of spondylosis in cane toad populations and suggested that the incidence of this condition did not increase as a physiological cost of invasion, but is instead related to physical variables, such as climate.


ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.


Order from Amazon

This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

Electronic Scholarly Publishing
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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).


ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.


Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )