Areas across the state are in the midst of a gypsy moth caterpillar outbreak. The hardest hit areas are dotted from Western New York to the Adirondacks, and especially clustering around the shores of Oneida Lake.
Concerned citizens have contacted the New York State Department of Conservation (DEC) to report problems with the invasive insect, which eats the leaves of a variety of trees including oak, maple, apple, crabapple, aspen, willow, birch, mountain ash, pine, and spruce.
DEC Forester Robert Cole said that gypsy moth populations naturally spike every 10-15 years, but this year’s plague is unusually severe and spreading. Each gypsy moth outbreak typically lasts two to three years. These outbreaks generally cycle out through natural factors such as viruses and funguses. These factors kill off excessive numbers of the gypsy moths, keeping populations in check. Currently, the DEC has no plans for reactive action against the infestation.
According to Cole, the most effective time window for action has passed. The caterpillars will begin to disappear in July as they become moths, he said. He does, however, recommend that homeowners take precautions to protect their properties against further damage from the gypsy moth caterpillars.
“Currently DEC does not have any sort of eradication program,” Cole said. “Typically this would be an aerial spray of large forested tracks. Private landowners are encouraged to survey their property and contact a private sprayer to treat their property. This works very well when the caterpillars are small. Unfortunately right now, the caterpillars have grown too large and the effectiveness of treatment has gone down.”
DEC suggests that at home, property owners can check trees for signs of damage. Check the newest leaves, as the caterpillars prefer to eat the softest, most tender leaves first. If gypsy moth caterpillars are a problem, the homeowner can create a sticky trap on the base of trees with duct tape, sticky side out, or a burlap trap for the insects to get trapped inside. Dispatch trapped caterpillars in soapy water. Use caution when handling traps because the caterpillars have prickly hairs that can irritate the skin on contact.
DEC reported that oak and apple trees are suffering the most damage this year due to the infestation.
Deciduous trees, meaning trees that annually lose their leaves, will generally produce second set of leaves in mid-summer and will survive, according to Cole. However, multiple years of defoliation can weaken trees and make them susceptible to disease and environment. Evergreen trees do not produce a second flush and are more susceptible to the gypsy moth’s attack.
Cole believes that New York’s deciduous trees, such as oak, will still produce enough in the second flush to sustain the wildlife that depends on the foliage for food.