You shouldn’t see much of the gypsy moth in Northeastern Pennsylvania this summer, or anywhere in the state for that matter.
Last week, the Department of Conservation and Natural Resources finished spraying pesticides combating the moth, which, in its larval stage, is known to cause tremendous damage.
According to DCNR Deputy Press Secretary Terry Brady, the state only sprayed private land in Clarion, Clearfield and Venango counties, all in western Pennsylvania. He said the state sprayed about 1,400 acres of land — much less than they expected — at the request of the landowners.
“We were bracing for widespread spraying,” Brady said, citing heavy defoliation in 2013, but this year’s wet, cold spring, promoted growth of a certain naturally recurring fungus.
The DCNR said the fungus, called entomophaga maimaiga, is toxic to the caterpillars, and alleviated the need for pesticides.
“The weather was our ally,” Brady said. “The population just collapsed.”
Gypsy moth populations grow exponentially, he explained. For example, he said a single moth might lay six eggs, which will each grow to lay six more and so on.
Once they hatch, the caterpillars begin feasting on the forest.
“Sometimes it sounds like rain when they’re eating and defecating,” he said. “It’s gross.”
According to figures released by the DCNR, the caterpillars defoliated more than 148,000 acres of forest in 2013.
Usually, Brady said, a tree can survive one defoliation and still thrive the same year, but subsequent defoliations leave plants susceptible to disease and death.
Brady said the lack of a “viable, large-scale population” of gypsy moths this year should curb damage, but pockets of infestation may still appear. As populations rise and fall, spraying will surely happen again next spring, but for now, he said, the state will adopt a wait-and-see attitude.
“Next year,” Brady said, “what we do will be based on defoliation this spring.”
But entomologists believe, he stressed, “the gypsy moth is here to stay.” He said eradicating the pest is not an option, as such heavy spraying would be not only cost prohibitive, but nearly impossible.
The pesticide used to fight the gypsy moths, he added, while deadly to the caterpillars, is safe for humans and plants.