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Abstract Adhesive ascidians have caused serious biofouling problems and huge economic losses in marine ecosystems. However, adhesion mechanisms, particularly on functional proteins involved in ascidian adhesion, remain largely unexplored. Here, we identified 26 representative stolon proteins from the highly invasive fouling ascidian Ciona robusta using the proteomics approach. The uncharacterized stolon proteins were rich in adhesion-related conserved domains. Real-time quantitative PCR further revealed specific expressions of these uncharacterized protein genes in stolon tissue, suggesting their potential roles in stolon adhesion.> A recombinant vWFA domain-containing uncharacterized protein, ascidian stolon protein 1 (ASP-1), was successfully expressed in a baculovirus-insect cell system and purified in vitro. Coating experiment showed that tyrosinase-modified ASP-1 could absorb to glass and organic glass stronger than unmodified ASP-1, while only modified ASP-1 could absorb to aluminum foil. Quartz crystal microbalance analysis also showed the increase in absorption ability of ASP-1 after modification. In addition, abundant 3,4-l-dihydroxyphenylalanine (DOPA) in modified protein was detected by nitroblue tetrazolium staining. These results suggest that ASP-1 be involved in ascidian DOPA-dependent and material-selective adhesion. Overall, this study provides insight into molecular mechanisms of C. robusta stolon adhesion, and findings here are expected to be conductive to develop strategies against biofouling caused by ascidians. Highlights • A variety of stolon proteins were obtained from the highly fouling ascidian. • Stolon proteins with conserved domains highly expressed in stolon tissue. • The stolon protein ASP-1 can selectively adhere to different material surfaces. • The adhesion of ASP-1 to materials was DOPA-dependent. [ABSTRACT FROM AUTHOR]

Biological invasions have far reaching effects on native plant and arthropod communities. This study evaluated the effect of natural enemies on eggs of the exotic invasive brown marmorated stink bug Halyomorpha halys (Stål) in experimental plots comprising species pairs of 16 ornamental trees and shrub genera from either Eurasia or North America and in wooded areas adjacent to the plots. Sentinel egg masses were placed on leaves of Acer , Cercis , Hydrangea , and Prunus in the plots and in seven genera of trees and shrubs in adjacent woods . Overall, rates of parasitism and predation in experimental plots were low, accounting for only 3.8% and 4.4% of egg mortality, respectively. There were no significant differences in parasitism and predation rates between native or exotic plots or between plants of different genera. In 2015, predation was significantly higher in the experimental plots than in the wooded sites, but parasitism was significantly higher in the wooded sites. In the experimental plots, seven native and one exotic parasitoid species attacked sentinel egg masses. Six native parasitoid species attacked sentinel egg masses in the wooded sites. Parasitoids in the genus Trissolcus were more likely to attack egg masses in exotic plots than in native plots. There is no evidence that native natural enemies attacking eggs of the exotic BMSB were more prevalent in landscapes with native ornamental trees and shrubs than those with exotic trees and shrubs. [ABSTRACT FROM AUTHOR]

Unintentional seed introduction mediated by visitor's clothing and footwear is a major source of biological invasion into natural areas. To effectively avert these unintentional introductions, we must understand the links that connect relevant knowledge and desired outcome (i.e., seeds not carried on visitor's belongings); however, until now, these links have not been examined. Here, we investigated the links among a visitor's knowledge about biological invasion, awareness of biological invasion, behavior to prevent introduction (cleaning footwear), and being a seed carrier to identify a potential bottleneck between visitor knowledge and ecological outcome. In order to achieve this, we conducted a questionnaire survey and soil sampling from the footwear of visitors to an alpine national park. Soil samples (n = 344) were subjected to a germination experiment, and the number of emerged seedlings was recorded for each sample. We observed seedlings emerging from 27 soil samples (7.8 % of visitors; 44 seedlings in total), comprising non-native species. The degree of a visitor's knowledge about biological invasion increased with the increase in the degree of awareness. However, the high degree of awareness was not linked with the actual behavior of cleaning their footwear before the visit, although footwear cleaning effectively reduced the number of emerged seedlings. We found the lack of a clear association between awareness and behavior (cleaning the footwear) to be the bottleneck. We also investigated the major sources of knowledge about human-mediated seed introduction from footwear and found that television was the most important information source. The key to effectively preventing negative impacts on ecosystems caused by the introduction of non-native species could be to revise methods for informing the community, which will help overcome the bottleneck between awareness and behavior. • Links between visitors' knowledge and biological invasion outcomes were explored. • Lack of association between awareness and actual behavior was the bottleneck. • Bridging the missing link is a key to prevent biological invasion into natural areas. [ABSTRACT FROM AUTHOR]

Abstract: Background: Scientific literature on biological invasions in the developing world is currently scarce. India, a fast-globalizing country, faces a high risk of biological invasions. However, research and policy efforts on biological invasions in India are presently inadequate. Objectives: To propose an integrated research framework and policy agenda on biological invasions for India. Methods: The framework and agenda, drawn from research insights gained from plant invasion studies in the Kashmir Himalaya (India), adopts a stage-based model for characterization of invasive alien biota in India. Results: The research framework explicates crucial information on the origin, purpose and pathway of introduction, residence time, species invasiveness, invasiveness elsewhere, habitat invasibility, latitudinal and altitudinal ranges and ecological and economic impacts of invasive species. The policy agenda highlights an urgent need for regulation of introduction pathways, prioritization of the worst invasive species, shifting from species- to biota-centric approaches, looking beyond political borders, forging interdisciplinary collaboration, launching a national network, and generating public awareness. Conclusions: Adoption of such an integrated framework and agenda in India, and in other developing countries, can significantly fill the geographical knowledge gaps in invasion biology research—which is crucial in winning the global battle against harmful biological invasions. [Copyright &y& Elsevier]

Abstract: Plant genotypic effects can alter insects’ ability of utilizing their host plant. Alligator weed, Alternanthera philoxeroides, is a South American amphibious Amaranthaceae, which invades aquatic and terrestrial habitats. Populations with varying morphotypes and cytotypes were identified and further associated with a polyploid hybrids complex in Argentina, which probably is the centre of origin and diversification of alligator weed. The current model of the hybrid complex formation proposes that diploid ancestors gave rise to allotetraploids and allohexaploids. Agasicles hygrophila is a monophagous chrysomelid beetle which successfully controls A. philoxeroides in regions with mild winters and where the weed grows in aquatic habitats. However, plant genetic characteristics could constrain insect development and reproduction, providing an alternative explanation for the restricted success of biological control of alligator weed with A. hygrophila. We investigated the effect of four A. philoxeroides populations with varying cytogenetical characteristics on plant–insect interaction with A. hygrophila in the native range of the weed. The insect’s life cycle on each host population was studied. In addition, the genetic relationships among the weed populations was explored using dot blot analysis. Plant population affected insect survival and fecundity, but not life cycle length nor third larval instar mortality, pupal mortality or female proportion. Plant internode diameter was not a restriction for insect pupation. All hexaploid populations of A. philoxeroides, as well as the close related A. aquatica, hybridized with the tetraploid population probe with similar intensity, meaning that this population is a component of their polyploid genome. [Copyright &y& Elsevier]

Abstract: To address how the spatial configuration of habitat fragmentation influences the persistence and the rate of spread of an invasive species, we consider three simple periodically fragmented environments, a lattice-like corridor environment, an island-like environment and a striped environment. By numerically analyzing Fisher’s equation with a spatially varying diffusion coefficient and the intrinsic growth rate, we find the following. (1) When the scale of fragmentation is sufficiently large, the minimum favorable area needed for successful invasion reduces in the following order: lattice-like corridor, striped and island-like environments. (2) When the scale of fragmentation and the fraction of favorable area are sufficiently large, the spreading speeds along contiguous favorable habitats in the lattice-like corridor and striped environments are faster than the speeds across isolated favorable habitats in the island-like environment and the striped environment. (3) When the periodicity of fragmentation is relaxed by stochastically shifting the boundaries between favorable and unfavorable habitats, the average speed increases with increases in the irregularity of fragmentation. [ABSTRACT FROM AUTHOR]

Abstract: Characteristic flora and fauna that are highly sensitive to disturbances colonize coastal detritic bottoms in the Mediterranean Sea. In the present study, a comparison of the assemblage composition and colonization by invasive macroalgae was made between two coastal detritic macrophyte assemblages, one dominated by rhodoliths (free-living non-geniculate Corallinales) and the other dominated by fleshy algae, in an area that has been exposed to important levels of anthropogenic disturbance, mainly pollution (including changed sedimentation regimes) in the recent past (bay of Marseilles, France). In comparison with less strongly impacted Mediterranean regions, the macrophyte assemblages in the bay of Marseilles were characteristic in terms of species identity and richness of coastal detritic macrophyte assemblages. However, extremely low species abundance (cover) was observed. As far as invasive species were concerned, Caulerpa racemosa var. cylindracea was only abundant in the rhodolith assemblage whereas the two invasive Rhodophyta Asparagopsis armata and Womersleyella setacea were mainly found in the fleshy algae assemblage. The seasonality observed in the Rhodolith assemblage seemed to be related to the development of C. racemosa var. cylindracea and did not follow the typical pattern of other Mediterranean assemblages. This study represents the first study of coastal detritic assemblages invaded by C. racemosa var. cylindracea. [Copyright &y& Elsevier]

Abstract: Spartina alterniflora is a salt marsh halophyte introduced to the Pacific Coast of the United States that has become a noxious weed in Willapa Bay, Washington. A sap-feeding insect has been released as part of a biological control program, which has established at multiple sites. A useful complement to this program would be a biological agent that attacks seed, to reduce expansion of the infestation by seedling recruitment. One possibility is the floral-infecting, fungal pathogen Claviceps purpurea, which causes the ergot disease. This species is comprised of three intraspecific groups, of which one is specific to salt marsh habitats, G3. Based on random amplified polymorphic DNA markers, all three intraspecific groups of C. purpurea were found on grasses in Willapa Bay. The incidence of ergot on Spartina was very low over the three-year sampling period. Genetic diversity was low among G3 isolates, suggesting it may have been recently introduced to the region. Greenhouse tests showed S. alterniflora from Washington to be as susceptible to C. purpurea as S. alterniflora from the Atlantic Coast, where ergot has reached epidemic levels. Neighbor-joining analysis of amplified fragment length polymorphism markers suggests that G3 C. purpurea in Washington is most closely related to Southeastern USA G3 C. purpurea. Pairwise comparisons as part of AMOVA showed that Willapa Bay isolates are different from those of all other geographic regions except Argentina. The low intensity of disease in Washington may be due, in part, to a G3 ergot population that is not well adapted to conditions in this area. [Copyright &y& Elsevier]

Land-use changes and biological invasions have converted the vegetation of California''s Central Valley and surrounding foothills from a mixture of perennial forbs and grasses and spring- and summer-flowering annuals to vegetation dominated by Eurasian spring-flowering annual grasses. The exotic annual grass communities are now rapidly being invaded by a Eurasian summer-flowering annual thistle that has caused losses of soil moisture resources on invaded sites of 15–25% of mean annual precipitation. A rough preliminary estimate indicates that the value of the lost water may range from 16 to 75 million dollars per year in the Sacramento River watershed alone. [Copyright &y& Elsevier]

Range expansion of a single species in a regularly striped environment is studied by using an extended Fisher model, in which the rates of diffusion and reproduction periodically fluctuate between favorable and unfavorable habitats. The model is analyzed for two initial conditions: the initial population density is concentrated on a straight line or at the origin. For each case, we derive a mathematical formula which characterizes the spatio-temporal pattern of range expansion. When initial distribution starts from a straight line, it evolves to a traveling periodic wave (TPW), whose frontal speed is analytically determinable. When the range starts from the origin, it tends to expand radially at a constant average speed in each direction (ray speed) keeping its frontal envelope in a similar shape. By examining the relation between the ray speed and the TPW speed, we derive the ray speed in a parametric form, from which the envelope of the expanding range can be predicted. Thus we analyze how the pattern and speed of the range expansion are affected by the pattern and scale of fragmentation, and the qualities of favorable and unfavorable habitats. The major results include: (1) The envelope of the expanding range show a variety of patterns, nearly circular, oval-like, spindle-like, depending on parameter values; (2) All these patterns are elongated in the direction of stripes; (3) When the scale of fragmentation is enlarged without changing the relative spatial pattern, the ray speed in any direction increases, i.e., the rate of range expansion increases. [Copyright &y& Elsevier]

Terrestrial invasive species threaten the integrity of diverse and highly-valued ecosystems. The Minnesota Invasive Terrestrial Plants and Pests Center (MITPPC) was established by the state of Minnesota to fund research projects aimed at minimizing harms posed by the most threatening terrestrial invasive species to the state's prairies, wetlands, forests, and agriculture. MITPPC used the Analytic Hierarchy Process (AHP) to identify and prioritize diverse invasive species threats. We describe how MITPPC tailored AHP to establish its research priorities and highlight major outcomes and challenges with our approach. We found that subject matter experts considered factors associated with the severity of impact from invasion, rather than the potential for invasion, to be the greatest contributors in identifying the most threatening species. Specifically, out of the 17 total criteria identified by the experts to rank species, negative environmental impact was the most influential threat criterion. Currently, narrowleaf cattail, mountain pine beetle, and the causative agent of Dutch elm disease are top threats to Minnesota terrestrial ecosystems. AHP does not handle data-poor situations well; however, it allows for easy incorporation of new information over time for a species without undoing the original framework. The MITPPC prioritization has encouraged interdisciplinary, cross-project synergy among its research projects. Such outcomes, coupled with the transparent and evidence-based decision structure, strengthen the credibility of MITPPC activities with many stakeholders. • Expert opinions differ about the threat posed by terrestrial invasive species. • The Analytic Hierarchy Process organized expert opinions into decision-support criteria. • Threat level was driven by impact of invasion more than the potential for invasion. • Environmental impacts were more important than economic impacts for ranking threats. • Decision transparency and consistency increase credibility with stakeholders. [ABSTRACT FROM AUTHOR]

• Various spatial patterns of biological invasion are compared to each other based on several topological indices. • A small change in the model parameters results in random fluctuations of topological indices when patchy spatial patterns are analysed. • The transition time required to establish topological properties of a spatial pattern must be taken into account in pattern recognition and analysis. We address the problem of pattern recognition and comparison when spatial patterns of biological invasions are studied. A model of biological invasion is employed to simulate spatio-temporal dynamics of invasive species and generate a variety of spatial patterns including so called 'no front' patchy spatial distributions. We introduce several topological indices to understand whether various spatial distributions of invasive species can be compared to each other based on information about their topology. We also investigate how topological indices used to make conclusions about the spatial pattern are related to controlling parameters in the underlying process of biological invasion. Our analysis reveals that a small increment in the model parameters results in a small increment in topological indices when the topology of continuous front spatial pattern with no patches behind the front is considered. Meanwhile, 'no front' patchy spatial distributions present a different case where a small change in the model parameters results in random fluctuations of topological indices. The 'random' behaviour of patchy patterns is further studied to understand whether a patchy spatial structure can transform itself into a continuous front spatial distribution over time. In the paper it will be argued that apart from the topological quantities used to classify spatial distributions, the transition time required to establish topological properties of the spatial pattern must be taken into account in pattern recognition and analysis. Furthermore, it will be demonstrated that for some parameter values it is impossible to conclude about the topological type of spatial pattern, i.e. continuous front spatial distributions cannot be distinguished from 'no front' patchy distributions of invasive species, no matter what their topological indices are. [ABSTRACT FROM AUTHOR]

Stakeholders are critical environmental managers in human-dominated landscapes. In some contexts, stakeholders can be forced to personally act following their own observations and risk perception instead of science recommendation. In particular, biological invasions need rapid control actions to reduce potential socio-ecological impacts, while science-based risk assessments are rather complex and time-delayed. Although they can lead to important detrimental effects on biodiversity, potential time-delayed disconnections between stakeholders' action and science recommendations are rarely studied. Using the case study of western European beekeepers controlling the invasive Asian hornet Vespa velutina nigrithorax for its suspected impact on honey bee colonies, we analysed mechanisms underlying personal actions of stakeholders and how they evolved in science disconnection. Personal actions of stakeholders were causal-effect linked with their risk observation but disconnected to time-delayed science predictions and recommendations. Unfortunately, these science-disconnected actions also led to dramatic impacts on numerous species of the local entomofauna. These results highlight the need to improve mutual risk communication between science and action in the early-stages of management plans to improve the sustainably of stakeholders' practices. • Current global changes can lead to time lags between science and action. • We analyse stakeholder actions and how they evolved in science disconnection. • Stakeholder actions are disconnected to time-delayed science recommendations. • Science-disconnected actions impact local biodiversity. • Improving risk communication to biological invasion is urgently required. [ABSTRACT FROM AUTHOR]