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2013 Winter Moth Survey

It’s that time of year again: winter moths and other related species have started to show up at porch lights across the state. The winter moth (Operophtera brumata) is an invasive species first discovered in Massachusetts in the 1990s. Winter moth caterpillars are highly efficient tree defoliators, often stripping the leaves of oaks, maples and other hardwood trees down to lacy skeletons.

In mid-to-late fall, at a time of year where insect activity is practically at a standstill, these small brown winter moths will be seen across the eastern half of the state, sometimes congregating at porch lights by the hundreds. There are other similar-looking native moths active at this time of year, such as the Bruce spanworm moth and the fall cankerworm moth, but they are typically not seen in such large numbers. While the state does not regulate winter moth, some towns/cities do tree treatments, and the Elkinton Lab at University of Massachusetts Amherst currently has a biological control program underway.

Male and female winter moth. Females have tiny, vestigial wings and are flightless.

If you see winter moths this November or December, we’d like to hear from you using the survey below. The information you share will help assess the distribution of this invasive pest in our state.

Helpful links:

  • For more information on winter moth biology and management, see this fact sheet from UMass Extension.
  • For more examples of male and female winter moths and related species, see this photo gallery.
  • If you would like to email a photo, please use our Pest Reporting Form.

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