While spiders are predators, they are themselves heavily preyed upon by mud-dauber wasps. Different mud-dauber species preferentially capture particular groups of spiders, but the bases for these preferences are not well understood. Spider web architecture has been considered to be a defensive behavior against wasp predation, with three- dimensional webs thought to provide more effective physical barriers than their two-dimensional counterparts. Surprisingly, initial results from our experiments indicate that the mud-dauber wasp, Sceliphron caementarium, does not base its foraging decisions on web characteristics. Rather, it uses chemical cues present on spiders and /or their webs to recognize its prey. The proposed study will address chemical mediation of prey preferences by wasps within an evolutionary framework. The results of this work will provide insights into whether other mud-dauber wasps use chemical cues to recognize spider prey, and whether all spider taxa taken by Sceliphron will share similar chemical profiles. This research will also help us to understand whether changes in chemical profiles of spider families may have allowed spider diversification via escape from wasp predation. The demonstration that prey preferences of spider-hunting wasps are mediated by spider chemicals is a significant contribution to our understanding of predator-prey interactions. This study will have broader impacts by providing educational and research opportunities to elementary school and undergraduate students through development of lesson plans designed to teach ecological concepts using mud-dauber nests.
