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An integral part to understanding the biology of an invasive species is determining its origin, particularly in pest species. As one of the oldest known invasive species, the goals of this study were to evaluate the evidence of a westward expansion of Hessian fly into North America, from a potential singular introduction event, and the population genetic structure of current populations. Levels of genetic diversity and population structure in the Hessian fly were compared across North America, Europe, North Africa, Western Asia, and New Zealand. Furthermore, Old World populations were evaluated as possible sources of introduction. We tested diversity and population structure by examining 18 microsatellite loci with coverage across all four Hessian fly chromosomes. Neither genetic diversity nor population genetic structure provided evidence of a westward movement from a single introduction in North America. Introduced populations in North America did not show identity or assignment to any Old World population, likely indicating a multiple introduction scenario with subsequent gene flow between populations. Diversity and selection were assessed on a chromosomal level, with no differences in diversity or selection between chromosomes or between native and introduced populations. [ABSTRACT FROM AUTHOR]

The western corn rootworm (Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) is a major coin insect pest in North America and is spreading in Europe. Seven polymorphic microsatellite loci were surveyed to characterize genetic structuring of D v. virgifera populations, based on 595 individuals sampled from 10 locations across nine U.S. states (western Texas and Kansas to New York and Delaware). All populations showed high levels of genetic diversity, with mean allefic diversity ranging from 7.3 to 8.6, and mean expected heterozygosity ranging from 0.600 to 0.670, D v. virgifera populations exhibited little genetic differentiation as a whole across the geographic range sampled, with a global FST of only 0.006. Pairwise FST estimates also revealed little genetic differentiation among populations. Most pairwise FST values were nonsignificant, except for those estimated between the Texas population and all others. There was a positive correlation between genetic distance and geographic distance as a whole, but no significant correlation for populations from Kansas to the east coast. There was no evidence for a genetic bottleneck in any D. v. virgifera population sampled. Phylogenetic and principal component analyses support the picture of high genetic similarity over much of the United States. Although high migration rates could produce the same pattern and cannot be ruled out, it seems more likely that the D v. virgifera populations sampled have had insufficient time for substantial genetic structuring to develop since its recent eastward range expansion from the Great Plains that began ≈50 yr ago. [ABSTRACT FROM AUTHOR]

Soybean aphid, Aphis glycines Matsumura, a native of eastern Asia, was first discovered in North America in July 2000 in Wisconsin and subsequently in a total of 10 North Central U.S. states by September 2000. Currently, soybean aphid has spread to 20 U.S. states and three Canadian provinces, putting >60 million acres of soybean at risk to crop injury caused by this exotic insect. The life history of this species has been studied by a number of entomologists and crop protection specialists, and here we provide a summary of the observations made by ourselves and our colleagues. The soybean aphid has been observed at all stages of a heterecious holocyclic life cycle and seems to be adapting to a large geographic area of the North Central United States. Soybean aphid uses native and exotic primary hosts found in North America, specifically Rhamnus cathartics L. and Rhamnus alnifolia L'Hér. The aphid's principal secondary host is soybean, Glycine max (L.) Men., but there seems to be a lengthy gap in early spring between the production of alatae on buckthorn (Rhamnus spp,) and the occurrence of soybean. In the fall when soybean is senescing, a biological bottleneck is created as the aphid must develop sexual morphs on soybean that emigrate back to the primary host to complete the sexual phase of its life cycle. During the summer, A. glycines is prone to develop winged morphs during any generation on soybean, which puts much of the soybean crop at risk of invasion by this exotic species, even if the insect does not overwinter locally. The integrated pest management challenges presented by the aphid require a deeper understanding of its biology as it adapts to North America. [ABSTRACT FROM AUTHOR]

Specimen identification keys are still the most commonly created tools used by systematic biologists to access biodiversity information. Creating identification keys requires analyzing and synthesizing large amounts of information from specimens and their descriptions and is a very labor-intensive and time-consuming activity. Automating the generation of identification keys from text descriptions becomes a highly attractive text mining application in the biodiversity domain. Fine-grained semantic annotation of morphological descriptions of organisms is a necessary first step in generating keys from text. Machine-readable ontologies are needed in this process because most biological characters are only implied (i.e., not stated) in descriptions. The immediate question to ask is “How well do existing ontologies support semantic annotation and automated key generation?” With the intention to either select an existing ontology or develop a unified ontology based on existing ones, this paper evaluates the coverage, semantic consistency, and inter-ontology agreement of a biodiversity character ontology and three plant glossaries that may be turned into ontologies. The coverage and semantic consistency of the ontology/glossaries are checked against the authoritative domain literature, namely, Flora of North America and Flora of China. The evaluation results suggest that more work is needed to improve the coverage and interoperability of the ontology/glossaries. More concepts need to be added to the ontology/glossaries and careful work is needed to improve the semantic consistency. The method used in this paper to evaluate the ontology/glossaries can be used to propose new candidate concepts from the domain literature and suggest appropriate definitions. [ABSTRACT FROM AUTHOR]

• To better understand invasion dynamics, it is essential to determine the influence of genetics and ecology in species persistence in both native and nonnative habitats. One approach is to assess patterns of selection on floral and growth traits of individuals in both habitats. • Mimulus guttatus (Phrymaceae) has a mixed mating system and grows under variable water conditions across its native and nonnative range in North America. Field investigations of patterns of selection of floral and plant size traits were conducted in two native and two nonnative populations. Field-collected seed was grown and crossed in the glasshouse using a paternal half-sib design. The resulting offspring were grown in saturated and dry-down low-water conditions and the same traits were measured in both environments. • Patterns of selection varied across years in the native range. Nonnative populations exhibited selection for increased floral size, consistent with the hypothesis that selection favors larger size in nonnative habitats. In the glasshouse, we detected genetic variation for traits across population/treatment combinations. However, size hierarchy in the glasshouse was dependent on water conditions. • Our results suggest that both variable selection pressures and local adaptation probably influence the persistence of both native and nonnative populations. [ABSTRACT FROM AUTHOR]