Chemical prey cues influence the urban microhabitat preferences of Western black widow spiders, Latrodectus hesperus

Spiders are important predators in terrestrial ecosystems, and several spider species have been shown to use chemical cues to locate prey. However, the extent to which chemical prey cues actually drive habitat use by individual spiders remains unclear. In this study we tested whether Western black widow spiders, Latrodectus hesperus Chamberlin & Ivie 1935, can detect chemical cues left by potential prey items and adjust their habitat preferences (i.e., web building behavior and refuge choice) accordingly. Using outdoor enclosures, we gave mature female widows the choice of microhabitat (rocks) previously housing cricket prey versus control rocks lacking cricket cues. Our results showed a significant preference by black widows to build their webs in areas that contain chemical prey cues. We discuss the implications of this finding for our understanding of urban black widow habitat use, population dynamics, and the potential for urban infestations.