Meeting Abstract

P1-7   -   Wolf Spider Predation: Foraging with a chance of meatballs Frauenheim, KP*; Adams, OR; Dell, AI; Jones, KS; Rhee, RS; Sahai, A; Seymoure, BM; Washington University in St Louis, St Louis, MO; Edward Waters University, Jacksonville, FL; Washington University in St Louis, St Louis, MO and The National Great Rivers Research and Education Center, Alton, IL; Washington University in St Louis, St Louis, MO; Washington University in St Louis, St Louis, MO; Saint Louis University, St Louis, MO; Living Earth Collaborative, Washington University in St Louis, St Louis, MO k.frauenheim@wustl.edu

Prey is not homogeneously distributed across space and time. Thus, adaptations that enable for multiple prey capture and/or handling will enable predators to monopolize prey capture during high prey abundance. Wolf spiders (Lycosidae) are one organism that has exhibited this adaptation. Instead of catching and eating one prey item at a time, these spiders have the ability to catch a multitude of prey at once and lump them together into a “meatball”. This behavior, called simultaneous handling, prepares them for times of prey scarcity. In this experiment, we studied how many flies a wolf spider can collect in their meatball in 30 minutes, paying specific attention to how this was affected by spider size and starvation. We predicted that as spider size increased, the number of flies in a spider’s meatball would also increase. We also predicted that spiders starved for a longer period of time would have more flies in their meatballs at the end of the experiment than those starved for a shorter period of time. To study these predictions, sixteen female Rabidosa rabida were collected during the day. Spider size was measured using prosoma width and ImageJ software. The spiders were starved for either one or seven days, and then each individual was placed into an arena with 30 flies (Drosophila hydei). We observed and conducted ethograms of foraging behavior for 30 minutes, tracking when spiders caught and dropped flies. We found that although the number of flies in a meatball varied across the different individuals, it was not significantly related to either spider size or starvation. We also analyzed the speed at which spiders added flies to their meatballs. It is imperative to understand the foraging behavior of wolf spiders as they provide an integral ecosystem service of depredating insect pests.