Educated, Experienced & Excited About What We Do!

Learn / Ask The Landscape Professional

I have these moths all over my house. What in the world are they? Help! Gerald


I have these moths all over my house. What in the world are they? Help! Gerald Gerald, what you are seeing is called a Winter Moth, Operophtera brumata. These moths are an invasive insect pest prevalent throughout Europe that first showed up in Nova Scotia after World War II. Since then, they have emerged in western Canada, Oregon and the state of Washington. Over the last ten to fifteen years, parts of eastern New England have become infested with them. The hardest hit areas are Massachusetts east of Route 495, especially Cape Cod and Martha's Vineyard. They have also been observed in Rhode Island, southeastern New Hampshire, Maine and steadily moving into Southeastern Connecticut.

The moth, which is the adult stage of the Winter Moth, first shows up around Thanksgiving and will be seen into January if the temperatures remain above freezing. The male Winter Moth will often be seen in large numbers flying around outside lights. The female Winter Moth has stubby wings and cannot fly. Once the eggs are laid, both male and female moths die but the eggs survive the winter. Each female lays ~150 eggs, often in the bark of trees. In April, when the temperature averages around 55 degrees, the eggs hatch into caterpillars that eventually grow to about an inch long. The caterpillars can show up in incredible numbers. The caterpillars feed on buds of leaves and flowers as well as on developed leaves of apple trees, crabapples, beech, cherries, blueberries, oaks, maples and a wide range of other trees and plants. After several years of complete defoliation, trees are seriously stressed to the point they can eventually die.

Help is already on the way in the form of a small fly called Cyzenis albicans, which has shown to be an effective biological control of Winter Moths in Nova Scotia and British Columbia. This fly is a parasite that infests the Winter Moth by laying its eggs on leaves eaten by the Winter Moth caterpillars and the fly eggs hatch inside the caterpillar. This fly is a specific control for the Winter Moths; when the Winter Moth disappears, so does the Cyzenis albicans fly. This control method is being led locally by UMASS Amherst. It is expected within a decade the Winter Moth will be no more of a nuisance than the Gypsy Moth.

View As PDF



About Linda Lillie



Lecture Series


Submit Your Question


The Official Landscape Company of Mystic Seaport and Mystic Aquarium
