The Effect of Social Gregariousness on the Foraging and Consensus Decision Making Behavior of the German Cockroach (Blattella germanica)

Eliza Balch Earlham College, Laura Caldwell Earlham College, Andrea Ball Earlham College
Faculty Sponsor(s): Brent Smith Earlham College
Domiciliary cockroaches are among the well studied socially gregarious but non-eusocial organisms that give us insight into how sociality can benefit organisms. In order to examine the adaptive significance of this behavior, we studied a colony of captive bred German cockroaches and their foraging choices based on olfactory social and food detection cues. Prior to trials, we starved test individuals for several days. We set up two dual-choice trials in which we allowed the individual cockroaches five minutes to decide between I: Food Vs. No Food (F/NF) chambers with no conspecifics present, and II: Food and Conspecifics Vs. No Food and Conspecifics (FC/NFC) chambers, then recorded the amount of time and the number of visits to each chamber. Through one-way ANOVA and Chi-square analyses we determined that our cockroaches preferentially chose to visit the food chamber in both the presence and absence of conspecifics In addition, they spent more time exploring both choices and less time in the central chamber making no choice when conspecifics were present, regardless of food, which may provide evidence of gregarious behavior. Social gregariousness lends itself to consensus decisions and group foraging techniques which may allow individuals to select more favorable/nutritious choices more quickly and accurately than through searching alone.
Oral Presentation

When & Where

11:30 AM
Gallahue Hall 101