Flatheaded Appletree Borer
Hosts: all fruit trees
Biology: Overwinter as larvae inside tree, and emerge as adult beetles in June-August (northern Utah). This insect is usually only a problem on stressed trees (drought, wounding, etc.) or when populations are high in an area. All fruit tree varieties are susceptible.
Symptoms: Oval-shaped exit holes; frass; loose, dead bark. The larvae can eventually girdle trunks which will kill young trees and trees with multiple attacks.
Monitoring: Watch for adult beetles May-July.
Treatment Threshold: No threshold determined.
Degree Day Model: None
Management Considerations: The key to management is to maintain healthy trees. Preventive trunk sprays may be necessary to kill hatching larvae.