Pest description and crop damage Adults are gray or off-white moths which are present in late fall and winter, hence the name. The larvae are pale green with a light stripe down their sides, up to 0.5 inch long. Larvae damage the buds, blooms, and leaves during the early season but are gone before fruit is large enough to damage. The defoliation can have a negative impact on fruit set and size. Symptoms of leaf feeding are distinct from leafroller larvae as the leaves are tied together with silken threads, but not rolled.
Biology and life history Flightless females deposit 100 to 200 eggs on stems of host plants in late fall and winter. Since the female cannot fly, populations of winter moth often are clumped, as all the eggs usually are deposited in one tree. The eggs hatch in early spring at the green tip stage, and larvae feed from then until petal fall. The larvae often drop on silken threads and are carried by the wind to new growth areas. They drop to the soil to pupate during the summer, and after the first severe frost, the adults emerge. There is one generation per year.
Pest monitoring Beginning in late March, inspect plants for evidence of feeding injury to buds, webbing of leaves, or larvae. Especially in coastal areas, this often will be the first caterpillar visible in the spring.
Home orchardists: Pick larvae when you find them and prune out infested growth.
Management-chemical control: HOME USE
There are no products registered for control of this pest in home gardens.