A boring presentation: Ambrosia beetles in Michigan apple orchards

Black stem borer (Xylosandrus germanus) is a long-known pest of apple orchards, particularly those with trees experiencing stress. Newly discovered in Michigan is a second species of ambrosia beetle, Anisandrus maiche, now also abundant and attacking apple trees. As stressors on trees increase from high density plantings, erratic climate, and other factors, these beetles are becoming more problematic in apple orchards with few options available. In 2023 and 2024, we studied phenology and abundance of these two beetle species, optimized trapping, their spatial distribution in apple orchards, and evaluated known repellents at different densities for reducing infestations. By unraveling the complexities of ambrosia beetle ecology and behavior in apple orchards, we aim to equip growers with knowledge to safeguard their trees and provide insecticide alternatives to their management.