The Gypsy moth-caterpillar is one of the most destructive insect pests to trees in residential, urban and rural wooded areas in the USA. This species attacks more than 500 tree species, and according to the United States Department of Agriculture, the annual economic cost of destructive Gypsy moth-caterpillar activity amounts to a whopping 30 million dollars. The economic impact of Gypsy moth-caterpillar activity is most significant within forested areas, but multiple city-wide infestations have occurred throughout Massachusetts over the last three decades. Not only do Gypsy moth-caterpillars defoliate and ultimately kill trees in residential yards, but the caterpillars also pose a public health threat in residential neighborhoods.

As a Gypsy caterpillar develops, it sheds its skin, which is covered with venomous hair-fibers. The wind may then blow these detached fibers through residential areas where they can easily make contact with human skin. When this occurs, residents often develop rashes that they cannot explain. Making direct physical contact with a Gypsy caterpillar will almost certainly cause a person to develop dermatitis as a result. These needle-like fibers remain stuck within human skin, causing painful venom to continuously enter the bloodstream. Unfortunately, residents of many Massachusetts neighborhoods are already feeling the pain of Gypsy moth caterpillars, but experts are not yet sure if this year will see another large scale outbreak.

The recent bouts of rain have been keeping Gypsy moth-caterpillars at bay, but the moth larvae did not hesitate to emerge once a warm and rain-free day arrived. One Framingham resident, Justin Kapust, was conducting yard work around his Oak tree on the first warm day of the year when he noticed his skin breaking out in rashes. Justin knew that the rashes were caused by the Gypsy caterpillar, as he had sustained similar rashes last year. During a doctor visit in 2018, Justin was told that he was allergic to the caterpillars. Luckily, Justin did not develop a serious rash this year, but he believes that many of his neighbors will, as every tree in his neighborhood is “loaded” with the insect pests. Today, some residential areas of Massachusetts still contain Gypsy moth-caterpillar populations that became established during outbreaks that occurred over a decade ago.

Have you ever found a caterpillar’s venomous hair-fibers stuck within your skin?