AMHERST, Mass. — The browntail moth (Euproctis chrysorrhoea) is an insect that was accidentally introduced to Massachusetts from Europe in 1897. By the early 1900s, it spread into all of New England and parts of Canada. The caterpillars of this species feed on oak, shadbush, cherry, beach plum, apple, rugosa rose, and other trees and shrubs.
While the feeding damage from the caterpillars on landscape specimens may be problematic, the primary cause for concern with regard to browntail moth is medical: the caterpillars of this species possess poisonous hairs that cause a rash similar to poison ivy, and in some sensitive individuals may cause trouble breathing or sometimes a more severe allergic reaction.
UMass Extension was recently made aware of reports of adult browntail moths coming to lights in Essex and Plymouth counties, as well as the Boston area (Chestnut Hill). While the presence of adult browntail moth in locations outside of Cape Cod represents a change in the recent historical distribution of this insect in Massachusetts, we do not believe browntail moth populations are elevated or widespread in MA at this time.
However, due to the medical concerns associated with this insect, we are recommending that green industry professionals working in Massachusetts, particularly in coastal areas of Barnstable, Essex, Norfolk, Plymouth, and Suffolk Counties, should review the information we provide below and be able to accurately identify this insect in all life stages. Key in this information is the note that they should avoid touching the caterpillars, pupae/cocoons, or the nests/webbing produced by this pest without protective eyewear, gloves, long sleeves, pants, and other protective clothing. (The adult moths themselves do not seem to produce highly irritating hairs, yet the hairs from the caterpillar and pupal stages may remain on the adults after they emerge.)
To report suspected browntail moth adults (at present, it is the adult stage of this insect that is active at this time of year) in Massachusetts, visit: https://massnrc.org/pests/
Landscape, Nursery and Urban Forestry Program
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