Green fruitworm

Green fruitworm caterpillars tunnel into developing apples and stone fruits during May and June in Western Washington. The larvae are smooth, pale green, and grow to about 1 inch long. Damage appears as deep, irregular holes in young fruit or calyx tissue; larvae feed internally, making them difficult to detect until serious damage occurs. Early detection requires examining developing fruit in late April and early May.

Scout fruit clusters during late April and early May for feeding punctures or small larvae. Remove infested fruit by hand when populations are light. For heavy populations, apply spinosad or biological insecticides targeting larvae before fruit damage progresses. Time applications to late April. In organic systems, monitor using traps and apply botanical insecticides at petal fall.