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Flatheaded Appletree Borer

 

flatheaded 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.