Cherry-Lesser appleworm

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.

It overwinters as a 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

  • acetamiprid
  • carbaryl
  • esfenvalerate
  • gamma-cyhalothrin
  • 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
  • pyrethrins-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

Dormant-season and delayed-dormant sprays

  • chlorpyrifos (Lorsban 75WG) at 2 lb/a. REI 4 days. Do not exceed one application of chlorpyrifos as a dormant or delayed-dormant per season. Avoid contact with foliage in sweet cherries as premature leaf drop may result. Extremely toxic to fish and aquatic invertebrates; avoid spray drift and runoff to surface waters.

Growing-season sprays

  • spinosad-
    • Entrust SC at 1.25 to 2.5 oz/a. REI 4 hr. PHI 7 days. OMRI-listed for organic use.
    • Success 2F at 4 to 8 fl oz/a. REI 4 hr. PHI 7 days. Do not exceed 29 fl oz/a per year. Results are best when applied at petal fall. May act slowly.