Greater Peachtree (Crown) Borer
Hosts: apricot, nectarine, peach
Biology: Adult clearwing moths begin activity in late June and females lay their eggs on the base of tree trunks (apricot, peach/nectarine, plum) or on upper roots through September. Young or stressed trees can be killed.
Symptoms: Tree decline or dieback; oozing gummosis mixed with frass at the soil-line of the tree.
Monitoring: Look for holes near the soil line and oozing gum mixed with frass. To determine when adults emerge, hang pheromone traps starting in mid June or 400 degree days after March 1. Leave traps up and check weekly to monitor pest population throughout the season.
Treatment Threshold: If peak trap catch is greater than 10/week, treatment may be needed, especially if you find an average of more than 1 empty pupal case per tree. For greater peachtree borer under mating disruption: average of 3 moths/trap.
Degree Day Model:
- Upper threshold: 87°F
- Lower threshold: 50°F
|adults begin flight (UT)||575-650|
|50% moths have flown||1290|
Management Considerations: Peachtree borer can be difficult to control because of the protection given them once they have entered the tree. Mating disruption (1+ acres) or preventive trunk sprays covering the upper roots and 12-18” of lower trunk are the main control tactic.