Meeting Abstract

P3.19  Wednesday, Jan. 6  The urban behavioral ecology of the Western black widow Latrodectus hesperus JOHNSON, JC*; TRUBL, P; MILES, L; Arizona State University at the West Campus jchadwick@asu.edu

The Western black widow spider spider Latrodectus hesperus is a pest species of medical importance. Black widow populations from urban habitats of Phoenix, AZ experience a drastically different environment than their counterparts from surrounding, undisturbed Sonoran desert habitats. Specifically, urban populations tend to be densely populated (e.g. infestations) and are characterized by high prey abundance, low prey diversity, and low enemy risk. In contrast, desert populations tend to be sparsely populated and are characterized by low prey abundance, high prey diversity and high enemy risk. Here we quantify a number of life history and behavioral variables across these populations to assess whether or not they are locally adapted to these ecological differences. In particular, we quantify the cannibalistic tendencies of these populations to test the two-tailed prediction that cannibalism may be heightened in urban populations due to high population densities and low prey diversity, or cannibalism may be reduced in urban populations due to relative food abundance and selection for increased social tolerance in dense congregations. Throughout we argue that an understanding of the impact urbanization has on local fauna is required if we wish to both reduce the impact we have on other organisms and reduce the risk that dangerous urban pests have on human populations.