Lesser appleworm
Grapholita prunivora
2 host plants
Last updated
Lesser appleworm caterpillars tunnel into developing stone fruits like Prunus cerasifera, creating holes with reddish-brown stained edges in affected fruit during May and June. The small caterpillars are pale and grow to about 0.5 inch long. Early infestations cause fruit drop or create tunneling damage that renders fruit unmarketable. You detect damage by examining young fruit in late April.
Scout fruit clusters in late April and early May for evidence of small caterpillars or entry punctures. Remove infested fruit by hand during early detection. For heavy populations, apply spinosad or biological insecticides targeting larvae before damage progresses. Time applications to late April. Monitor for additional generations if temperatures remain cool.
Quick Reference
This is a tortricid pest similar in habit to the 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...