Managing flatheaded borers in nursery production without insecticides

Flatheaded borers in the genus Chrysobothris are native pests of tree crops across North America. In Tennessee, they are of special concern in field grown nursery production. Females lay eggs at the base of newly transplanted trees and larvae tunnel through the cambium tissue. Larval feeding can result in culled trees due to aesthetic damage or tree death if the plant is sufficiently girdled. Current management recommendations include basal drenches of imidacloprid, which protects trees from borers for up to 3 years. This treatment program is not without concerns, both from pollinator health and consumer acceptance perspectives. Alternative management practices for borer control may include the use of cover crops and barrier products. Previous research has shown that borer management can be achieved using winter cover crops. Barrier products may also present options for borer control. Updated recommendations for Chrysobothris management and proposals for future investigations will be discussed.