Grapholita prunivora
Pest description and crop damage This is a tortricid pest similar in habit to Oriental fruit moth. The larvae feed inside the fruit; often entering through the calyx end. It is an internal fruit feeder. Lesser appleworm is not currently a problem in commercial orchards. It is a moth native to the northeastern US that was first discovered in the Pacific Northwest in the 1940s in the Milton-Freewater area, where it has been most problematic. Insecticides applied for fruittree leafroller control should help control lesser appleworm.
Biology and life history The lesser appleworm prefers host plants in the rose family, including crabapples, hawthorn, wild rose and others. This caterpillar overwinters as mature larvae within a cocoon at the base of host plants under debris. The adults begin to emerge in April, and females lay eggs on leaves or the fruit surface. The larvae feed on the fruit for about three weeks, and then pupate at the base of the tree or under bark scales. Second-generation adults appear in late spring. These also lay eggs on the fruit. Late in the season, mature larvae spin cocoons to overwinter.
Adults and larvae are similar to the codling moth, but all stages are smaller.
Management-chemical control: HOME USE
Warning: Many pesticides are hazardous to bees. Look for bee precautionary statements on product labels and do not use these products during bloom or if bees are foraging in the orchard.
- carbaryl-Highly toxic to bees.
- esfenvalerate-Highly toxic to bees.
- gamma-cyhalothrin-Highly toxic to bees.
- kaolin clay (Surround at Home)-Repels some insect pests when applied as a spray to leaves, stems, and fruit. OMRI-listed for organic use.
- lambda-cyhalothrin-Highly toxic to bees.
- zeta-cypermethrin-Highly toxic to bees.
Management-chemical control: COMMERCIAL USE
Growing-season sprays
- spinosad (Entrust SC) at 0.06 to 0.12 lb ai/A (4 to 8 fl oz/A). REI 4 hr. PHI 7 days. Results are best when applied at petal fall. OMRI-listed for organic use. May act slowly. Do not exceed 0.45 lb ai/A spinosad or 29 fl oz/A per year.