The browntail moth caterpillar is an invasive insect pest that you do not want to encounter. This caterpillar’s barbed hairs contain histamines that cause a poison ivy-like rash on human skin. Brushing against one of these caterpillars will certainly cause these rashes, but their hair fibers become airborne when the caterpillars molt. The wind can blow these hair fibers onto people’s skin and clothes, even when the caterpillars themselves are not located anywhere near a human. These hair fibers are especially dangerous to asthmatics who may inhale the fibers unwittingly. For the time being, browntail moth caterpillars in Massachusetts are limited to Cape Cod, but many experts believe that it is only a matter of time before the potentially dangerous insect larvae spread to new areas of the state.

The browntail moth was first introduced into the United States after the insect was accidentally transported to Somerville from Europe back in 1897. During the early 1900s, browntail moth populations exploded across New England and southern Canada, causing panic among the populace. Eventually, the caterpillar’s population retreated into Portland, Maine and Cape Cod during the 1960s. The caterpillars are still largely limited to these regions, but they have recently spread to new areas of Maine where they are being considered a public health threat, and researchers in Massachusetts are worried that the same might happen in their state. One entomologist from the University of Massachusetts, Joseph Elkington, believes that the caterpillars pose a threat to the entire country, and he claims that officials in Massachusetts should be working harder to eradicate this species entirely before another population explosion takes place. Elkington has even put forth several eradication methods, one of which involves releasing a disease that only infects the caterpillars, but so far, Cape Cod health officials have prevented such measures from being taken. Several residents of Maine have developed rashes after making contact with this species’ hair fibers, and Massachusetts may be just as vulnerable to browntail population expansion. Only time will tell whether these caterpillars become a public health threat throughout the state, but for now, residents and tourists in Cape Cod should be mindful of this caterpillar’s invasive presence in the area.

Have you ever heard of the browntail moth? Are you worried about its possible spread into residential areas of Massachusetts?