Field Identification
A small moth whose larvae bore into tender peach, nectarine, almond, and apricot shoots, causing flagged tips and dieback, and later generations may enter fruit near the stem. Damage is often confused with bacterial canker or shot hole until you split the twig and find tunneling. Present in stone-fruit belts of North America, southern South America where Prunus is grown, and matching climates in between—roughly zones 5–10—with multiple generations where summers are long.
Adults are slender gray moths; larvae are pinkish brown with a dark head and longitudinal stripes. First hits show as wilting shoot tips in spring; summer larvae can scar fruit shoulders. Frass at tunnel openings confirms borer rather than fungal dieback.
How to Deal With It
Organic Control Methods
Bacillus thuringiensis kurstaki or aizawai applied during egg hatch and small larval windows on flagged shoots can be effective if thorough. Spinosad follows stone-fruit labels where available for lepidopteran larvae. Timing beats material choice—use degree-day models or pheromone trap biofix if offered locally.
Trichogramma spp. egg parasitoids are used in some integrated programs; braconid and ichneumonid wasps attack larvae. Ants climbing trees to tend other insects can disrupt parasitism—manage honeydew producers nearby.
Prune and destroy flagged shoots during spring and early summer before larvae move to fruit. Remove wild Prunus near orchards that harbor flights. Thin fruit clusters to reduce tight pockets where larvae hide from sprays and predators.
Snap wilted tips below the tunnel and burn or solarize in sealed bags—feasible on backyard trees and small plots. Fine netting on dwarf trees is impractical at scale but helps demonstration plantings.
Hang pheromone traps for monitoring, not magic control. Record first catch dates yearly. Combine trap data with shoot walks every 10–14 days during rapid growth.
Let Nature Handle It
Natural Enemies
- Trichogramma spp.
- Braconid Wasps
- Ichneumonid Wasps
- Lacewing larvae (Chrysopidae)
Threat Map