Millions of hungry gypsy moth caterpillars have returned to some parts of Eastern Massachusetts’ woodlands. The outbreak has already taken over more than 100,000 acres of land between Quabbin Reservoir and Cape Cod.

Authorities say this is the worst outbreak in the area since 1981 when the insects consumed almost all of the leaves of cherry, pine and oak trees, destroying more than 200,000 acres of land.  Residents of Massachusetts liken the current state of the woodlands to a scene out of a horror movie.

The outbreak usually starts in May. The insects were not originally from the US, as they were brought from Europe.

moth caterpillars

Gypsy moth caterpillar. Credit: Wikimedia/ Materialscientist

A French scientist tried to mass produce silkworms by experimenting with gypsy moths in 1869. A wind blew the caterpillars out of the scientist’s window, and two decades later, the first outbreak took place.  Since 1980, the caterpillars have defoliated nearly 1 million acres of forest in the eastern US every year.

However, authorities have learned to control the caterpillar population with the intentional release of Entomophaga maimaiga, a fungus that eats the gypsy moth caterpillars from the inside. Entomophaga maimaiga is endemic to the eastern US, so it is not difficult to procure and its spores can still live even if the population of caterpillars is lower than normal.

Still, this year’s outbreak could be blamed to the dry weather that was not conducive to the fungi’s survival, according to officials in the Bay State. On the other hand, experts believe that the invasion could be due to the cyclical changes in the moth populations that happen in different locations.

Moreover, experts warn that the outbreak could be worse next year. The Connecticut Agricultural Experiment Station says the fungi may not be good enough in controlling the infestation as they used to.

“Connecticut is potentially facing a huge gypsy moth infestation next summer,” chief CAES scientist Kirby Stafford told Hartford Courant. “If you already have trees that have been defoliated and stripped, you may need to go ahead and think about doing some control on the caterpillars next year. You probably will not be able to rely on fungus. Homeowners may have to spray to protect trees early next summer.”