Effects of Dehydration on Burrowing Behavior in Darkling Beetles in Broiler Chicken Litter

• Bukola Molake, Biological Sciences, University of Maryland: Baltimore County

• Michael Crossley, epartment of Entomology and Wildlife Ecology, University of Delaware

Chickens are the second most consumed protein in the world, but the farms that grow them are plagued by a ubiquitous insect pest, the darkling beetle, Alphitobius diaperinus. Darkling beetles live buried in the chicken litter of broiler houses. This burrowing behavior helps them evade predation and insecticide sprays, but the specific drivers are unknown. Here, we assessed the effects of dehydration on darkling beetle burrowing behavior using experimental models that simulate the floor of a chicken house. Darkling beetles readily burrow into the litter, particularly when exposed to light. However, beetles that had been dehydrated with a desiccant, over several days, tended to move along the litter surface instead of burrowing, even when exposed to light. These findings suggest that darkling beetles will seek shelter in their substrate by burrowing unless foraging for resources, such as water. While other factors remain to be explored, our results suggest that maintaining low moisture in chicken houses can increase surface movement among beetles. This will enhance management interventions dependent on direct contact.