Aggression and Mating Behavior in Wild and Captive Populations of the House Cricket, Acheta domesticus

Animals in captivity experience drastically different selective pressures than their wild counterparts. This can cause evolutionary divergence in behavior between captive and wild populations. While most research on evolution under captivity has focused on vertebrates, we expect similar behavioral changes in insects that live and breed in commercial facilities. Using the common house cricket, Acheta domesticus, we tested how crickets reared in captivity for many generations differed from wild-caught counterparts in two aspects of social behavior: male aggression and female responsiveness to male calling song. Acheta domesticus is an important model organism for behavioral research and are often reared in dense, commercial facilities with ad-libitum access to food and no risk of mortality from predators— very different conditions from the wild. We predicted that commercially-derived males would exhibit less intrasexual aggression due to selection from living in dense conditions. We predicted that commercially-derived females would be less responsive to male calling song because they are more likely to encounter many males at random. Instead, we found that commercially-derived males were more aggressive than wild ones, and that commercially-derived and wild females did not differ in responsiveness to calling song. Insects serve as model systems for a great deal of research in evolutionary and behavioral biology. If these animals are evolving in captivity, they may not provide an accurate representation of the natural phenomena we aim to understand.