Winter moth mix

Male winter moth	Female winter moth

With nighttime temperatures about to rise above freezing again over the next few days, expect to see even more winter moths hovering around your porch lights. Entomologists are saying that winter moth populations are on the rebound this year, with populations larger than we've seen for a while. The insects you'll see fluttering about are all males. The females are practically wingless and spend their days on tree trunks or other surfaces, waiting for a male to mate with. Adult moths are mainly a nuisance right now - they do all of their damage in the caterpillar stage, as tiny green larvae that can be found munching on the leaf buds of cherry, crabapple and other trees in early spring.

True winter moths (Operophtera brumata) are thought to have been introduced to the USA from Europe around 2000. As with most invasive species, the winter moth situation is not a simple one. The Elkinton Lab at UMass Amherst has found evidence that the introduced moths have been hybridizing with a similar-looking but less common native species, the Bruce spanworm moth (Operophtera bruceata). The lab continues to study this phenomenon and the impact it could have on the native species as well as on efforts to establish a biological control for winter moths in our state.

Winter moth resources:

• Our winter moth fact sheet
  
• Recommended treatments from UMass Extension