ROCHESTER, N.Y. (WROC) — The infamous return of the spongy moth, previously known as gypsy moths, is expected to occur across the state again this summer with concerns about more damage being done to trees and local foliage.

The spongy moth, previously known as the gypsy moth, is an invasive species we all became especially familiar with back in 2021 when high populations of the caterpillars were causing damage to leaves and foliage across the state and creating a nuisance to local parks’ backyards. As DEC Forester Rob Cole explains, we’re not quite done seeing the moths.

Last year, we had about 730,000 acres of defoliation that were mapped. This year, based on the reports we’re getting from the public, and egg mass surveys that we completed over the winter, we’re expecting this year to be another big year of defoliation,” DEC Forester Rob Cole said.

Places with especially high leaf damage to trees included right here in Monroe County, but also included places like Orleans Yates, Livingston, Yates, and Ontario counties.

Trees favored by the moths can usually withstand two to three successive years of defoliation without being killed. But the damage being done during the caterpillar stage still reduces the resistance of the tree making it more susceptible to pests and diseases.

“Right now the caterpillars are very small, dark color, about a quarter-inch long… in the next couple of weeks, they’ll molt into the later instars where they get those characteristic red or blue dots on their back and as they age and feed more, they’ll get larger and the actual moth we’ll see probably later in July,” Rob said.

Although spongy moths don’t currently pose a major threat to New York forests, there are ways to easily trap them in hopes of preventing more damage.

“A homeowner, if they have a spongy moth on their property, there are a few things they can do such as using sticky bands or burlap bags wrapped around the trunk of their trees to catch the spongy moth as they crawl up and down the tree,” Rob said.

Trees most favored by the insect to watch include oak, maple, willow, and other hardwood trees.

The broadleaf trees’ spongy moths favor can produce a new set of leaves after they’ve been defoliated such as oak trees, but other trees such as evergreens like pine, spruce, and hemlock do not regrow leaves as easily and can die as a result of complete defoliation. Since the species is expected to show up again this year, the concern lies in the areas that have already seen the damage.

Spongy moth outbreaks are cyclical and occur every 10-15 years with the highest outbreaks lasting around two to three, so while populations will likely go down in the next couple of years the DEC has already taken action in the most hard-hit areas with aerial treatments where the most damage has been done, primarily in state parks outside of Western New York to hopefully prevent any permanent tree damage.

Squishing and scraping tactics work with low populations of insects. Spongy moth caterpillars and adults can be killed by squishing them. Egg masses can be destroyed by scraping them off trees or other structures and dropping them in a container of detergent.

Using bands, barriers, and traps is another effective method. In late April, sticky/barrier bands may be placed around the tree’s trunk to catch caterpillars when they hatch and crawl.

These bands can be bought or made at home using common household materials.

More info about spongy moths in New York State here.