Gypsy moth caterpillar invasion: ‘It’s a plague’

DEC fields reports from residents across Adirondacks about infestation of gypsy moth caterpillars

By Megan Plete Postol

Portions of the Adirondacks are among the numerous locations across the state affected by an increase in gypsy moth caterpillars this year. 

Representatives from the New York State Department of Conservation reported that they have had numerous concerned citizens contact them about the invasive insect. The damage occurs when the caterpillar (larva) eats the leaves of many trees including oak, maple, apple, crabapple, aspen, willow, birch, mountain ash, pine and spruce.

DEC Forester Robert Cole said that although gypsy moth populations naturally spike every 10-15 years, this year’s infestation is uncharacteristic. 

“The outbreak started very heavily last year,” Cole said. “New this year is the infestation moving throughout the southern Adirondacks. We did not see that last year.”

He said the hardest hit areas of the Adirondacks were the southern region, including portions of Saratoga and Fulton counties, north in Clinton County and west of the Adirondacks clustering around Oneida Lake. 

In the above video recorded Tuesday, Cole gave a presentation about gypsy moth caterpillars.

Waiting it through

Each gypsy moth outbreak typically lasts two to three years. These outbreaks generally cycle out through natural factors such as viruses and funguses that kill off excessive numbers of the gypsy moths. DEC has no plans in place for action against the infestation, as the most effective time window to deal with the gypsy moth caterpillars has passed.

“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 the treatment has gone down.”

For the past week, Diane Parmeter Wills has been picking caterpillars by the hundreds off her two apple trees at her home in Peru (Clinton County), in the northeastern part of the park.

Wills estimates she pulled 2,000 the first day, (easily sliding bunches of them into a pail), 1,000 the second, 600 the third, and 250 on the fourth day, with still more to do.

“All of the pines, oaks and shade bushes have them, as well. I have never seen so many gypsy moth caterpillars,” she said. Wills, who is retired, spent hours one day on her eradication attempts. “They are everywhere.  It’s a plague.”

Concerns about lasting tree damage

Some of the concerns that have been expressed to DEC include the heavy damage to acorn-producing oak trees across the southern Adirondacks. Cole believes the oak trees will produce a new flush of foliage in July. He predicts that the trees will still be able to produce acorns, and that the wildlife that feed off of those acorns will be affected minimally, if at all.

Keith Wiggand of Forestport has seen these pests come and go and is not concerned. 

“Around 25 years ago they predicted all the forests would be destroyed in the Adirondacks by these guys and the trees eventually made their own protective toxins and the caterpillars disappeared,” he said.

What to do about it

DEC suggests two home remedies to combat the invasion on personal property:

CREATE A STICKY SITUATION: The first is to cover the base of the tree trunk with a sticky material, such as duct tape, to trap the caterpillars as they crawl up the tree. The sticky side should be faced outward, not inward, because placing a sticky substance directly on the bark could damage the tree.

IF YOU CAN’T BEAT THEM, TRAP THEM: The second is to trap the caterpillars during the pupae stage by creating a burlap trap. To make a trap, wrap a 12-18 inch-wide section of burlap around the tree and overlap it a few inches. Tie a string around the center of the burlap and allow the top six inches to flop over to make a two-layered skirt. The gypsy moths will nestle into the trap. Check the trap frequently and remove the caterpillars. Use rubber gloves while checking the traps because gypsy moth caterpillars have hairs that can potentially irritate the skin. Place the collected caterpillars in a container of soapy water to kill them. Burlap traps can be removed in August.

For more information, go to DEC’s webpage about gypsy moths.

Note: Explorer’s digital editor Melissa Hart contributed to this article.