D3077: Effects of cold acclimation on movement patterns in the lesser grain borer, Rhyzopertha dominica F.

The lesser grain borer, Rhyzopertha dominica (Coleoptera: Bostrichidae), is a pest of stored products, causing millions of dollars in damage to raw grain each year. Beyond grain storage bins, R. dominica is found in various agroecosystems and natural habitats, navigating these landscapes for resources like food and shelter. While it is known that these insects move between native and agroecosystem habitats, feeding on both native flora and stored grain, their overwintering behavior is not well understood. Specifically, it remains unclear how these insects overwinter in either habitat type, or how climate change might affect this insect’s behavior, physiology, or survival. To address these questions, we will study the walking behavior of adult R. dominica to determine whether acclimation at 18°C for 24 hours affects movement patterns such as knockdown time, total distance walked, and average velocity at 20, 10, and 0°C. Differences between insects will be assessed in wild versus lab strains and control versus acclimated individuals. Movement will be quantified using EthoVision and analyzed with R. We hypothesize that acclimated insects will show increased time to knockdown, distance traveled, and velocity at colder temperatures compared to non-acclimated beetles. These findings will help in targeting the movement patterns of R. dominica, aiding in the prevention of infestations of stored grain and offer insights into this insect’s overwintering biology, such as the utilization of alternative habitats to overwinter in the natural environment and dispersal potential after both extreme and mild climatic events.