Studies of distribution, population ecology, and genetics of brown recluse spiders, Loxosceles reclusa (Araneae: Sicariidae), in urban habitats

I performed a series of ecological, demographic and genetic studies designed to examine attributes of urban populations of brown recluse spiders, Loxosceles reclusa Gertsch and Mulaik 1940. I first review historical documentation of L. reclusa and present a study of geographic distribution. I then present my studies on aspects of population ecology through trapping methods to sample insect and arthropod fauna in houses. Last I focused on the population genetic composition of L. reclusa in urban habitats.; I used sticky traps placed throughout houses and pitfall traps placed outside of houses to record the abundance, density, and phenology of L. reclusa during a two-year study. Trapping studies showed that populations of L. reclusa in urban habitats exhibit a seasonal cycle of abundance, with a peak of activity in July. Loxosceles reclusa was found inside and on the outside grounds of houses in relatively high numbers. Trapping studies also revealed information on several behavioral attributes of L. reclusa.; I used specimens of L. reclusa collected during ecological studies to examine genetic diversity and structure within and among houses in Lawrence, Kansas and asked the questions: (1) Do populations of L. reclusa from houses in close proximity share higher relatedness than populations from distant houses? (2) How much variation exists within and among local populations? and (3) Do populations of L. reclusa in urban habitats exhibit strong genetic differentiation among populations? The mean within-population expected heterozygosity under Hardy-Weinberg genotypic proportions was relatively high for L. reclusa, which is an indicator of significant population structuring. Populations also exhibited relatively high within-population genetic diversity.; In populations of L. reclusa from urban habitats, many factors had a significant relationship with increased abundance. The most important variables were roof type and home exterior. Many other characteristics and features of houses were not found to have a relationship with L. reclusa abundance.; The abundance, distribution, and genetic composition of urban populations of L. reclusa may result from interactions of complex processes and factors. Therefore, these factors should be addressed through the integration of ecological, behavioral, demographic and genetic studies, such as the studies presented here.