Officials from the Massachusetts Department of Conservation and Recreation say the invasive gypsy moth species ate away at foliage in some pockets of the state, but the loss of acreage will not be as large as last year.
While in the caterpillar phase, the gypsy moths made the largest impacts in the city of Worcester, in the Pioneer Valley and on the North Shore, according to Ken Gooch, the forest health program director at DCR.
"Worcester proper, the whole city of Worcester, got hit pretty hard this year," Gooch said.
Damage by the gypsy moths is not drastically different than last year, Gooch said, but the impacts can be seen more in areas that have been defoliated multiple seasons in a row.
The gypsy moth is native to Europe and Asia. French artist, astronomer and amateur entomologist Leopold Trouvelot imported some eggs of the species to Medford in 1869, hoping to breed it to spin silk. But the caterpillars escaped into his backyard and have spread across the state since.
The species grows from egg to caterpillar, to pupa and finally to an adult moth.
As moths, the gypsies mate in July or August and each female deposits masses of between 75 to 1,000 eggs, according to Mass Audobon. They die after mating.
While damage from the gypsy moths does not appear to be as widespread this year, there were some parts of the state that have trees going through a second season of defoliation.
Sturbridge has suffered, Gooch said, and the South Shore is also seeing some of those effects.
Defoliation on top of three years of drought from 2014 to 2016 has proved harmful to the trees.
Last year, there was a severe outbreak of gypsy moths that caused 930,000 acres of defoliation. DCR has not finished its calculation for damage this year but expects that the number of acres will be smaller.
But despite the thinning of leaves, Gooch says the gypsy moths will not have an overly negative impact on leaf-peeping come fall.
The trees that provide the bright foliage New England is known for are mostly maple trees, and gypsy moths more typically feed on oak trees.
In fall, the leaves of oak trees turn a more purple-red hue, Gooch said. As long as trees that have been eaten by gypsy moths re-foliate, their leaves will still turn come fall.
But the trees attacked by gypsy moths can only re-foliate if they are healthy enough, Gooch explained. Pushing out new leaves after being annihilated by caterpillars uses a lot of the plant's preserves.
One thing that has helped to control the gypsy moth population is the Entomophaga maimaiga fungus, which infects the skin of the gypsy moth when in caterpillar form. Last year, the fungus killed off a massive amount of the species.
However, experts are surprised to see that the fungus has not had much of an impact this season.
"It's a little bit disturbing that the gypsy moth has made it to the moth stage and that the female is laying eggs," Gooch said.
Come the fall, DCR will do an egg mass survey to predict how the gypsy moths will be next year.