Domestication reduces caterpillar response to auditory predator cues

Domestication can lead to significant changes in the growth and behavior of organisms. While the threat of predation is a strong selective force in the wild, the relaxation or removal of this threat in captive-rearing environments selects for reduced sensitivity to biotic stressors. Previous work has documented such changes in other taxa, but no work has been done on domestication-related losses of predation risk sensitivity in insects. We exposed both wild and domesticated (>50 generations in captivity) Lymantria dispar dispar (Lepidoptera: Erebidae) larvae to recordings of predators (wasp buzzing), nonpredators (mosquito buzzing), or no sound to compare the effects of predation risk on the two stocks. Wasp buzzing, but not mosquito buzzing, decreased survival of wild caterpillars relative to the control; domesticated caterpillars showed no such response. Domesticated L. dispar larvae appear to have reduced sensitivity to predation risk cues, suggesting that captive-reared insects may not always be analogs to their wild counterparts for risk-related behavioral studies.