Defoliator (Caterpillars and Winter Moth)

Pest Alert

According to University of Massachusetts Extension Specialists and other experts, tree defoliating caterpillars could cause extensive damage to trees in a few weeks especially along the coastal areas of Massachusetts, most notably, Southeastern parts, including the Cape, and as far west as Wellesley.

During the past several years, populations of native caterpillar pests such as cankerworm, gypsy, forest tent, eastern tent and the newly discovered Winter Moth (Operophtera brumata) have exploded causing serious defoliation of trees and puzzling experts.

The Winter Moth is an introduced pest from England and as such has no natural biological controls here to limit it population density. With no natural controls at this time (research is anticipated to establish natural controls in the near future), applications of pesticides are the only meaningful remedy to protect trees from defoliation.

Those trees that have been defoliated in the past several years may not be able to withstand further defoliation if not protected.


To learn more about the winter moth visit the following links.

Winter moth overview- Umass (.pdf)
http://www.umassgreeninfo.org/fact_sheets/defoliators/wm_overview_06.pdf