A Technical Report from The Bartlett Tree Research Laboratories
Winter moth is primarily a pest of deciduous plants. Common hosts include, but are not limited to oak, maple, basswood, ash, apple, and crabapple. Winter moth causes injury to trees when larvae (caterpillars) tunnel into buds to feed. Larvae continue feeding as they move from bud to bud. Defoliation occurs as older larvae feed in the expanding leaf clusters. Delayed leaf expansion due to cool springs can increase injury. An effective pest management programme that consists of cultural and product treatments is necessary to promote tree vigor while suppressing populations of the insect.