Green Peach Aphid
Biology: Overwinter as eggs at the base of buds in peach/nectarine trees. Migrate to alternate hosts during summer.
Symptoms/Damage: Curled leaves; honeydew; feeding on nectarine fruit results in deformities; reduced tree vigor; aborted fruit.
Monitoring: Beginning at petal fall, inspect the undersides of leaves for new colonies. For faster inspection, shake limbs over a cloth tray (“beating tray”) to observe the dislodged insects.
Treatment Threshold: Treat peaches with 2+ colonies/tree before shuck split or 6+ colonies/tree after shuck split; treat nectarines at 1 colony/tree at any time.
Degree Day Model:
- Upper threshold: 82°F
- Lower threshold: 39°F
- Degree days required for one generation: 274
Management Considerations: Numerous beneficial insects including lady beetle, lacewing larvae, and syrphid fly larvae help suppress aphid populations.