Invasive caterpillars in upstate New York

They may look cute and furry, and seeing a few of them isn’t much of a problem, but these invasive caterpillars can be destructive and nasty, and an outbreak of them last summer caused noticeable damage to trees and leaves in parts of Upstate New York they have invaded. And this spring, they seem to be everywhere!

They’re called spongy moth caterpillars, and according to the DEC, “populations rise and fall in cycles of about 10 to 15 years.”

The DEC notes that in some years tree damage is minor, but large numbers of caterpillars (as many report in parts of upstate New York) can cause very noticeable damage to leaves and defoliation of trees trees.

They primarily feed on oak trees according to the DEC, but in New York, gypsy moth caterpillars are known to feed on the leaves of a wide variety of trees such as maple, apple, crabapple, hickory, basswood, aspen, willow, birch, pine, spruce, hemlock, etc.

Tree death can occur when other stresses such as disease or other insect outbreaks attack the trees in the same year. -NYS DEC

A Facebook post from a woman who lives in Saratoga County showed what appeared to be dozens (if not more) crawling over a fence and on the ground at a dog park she says is near SPAC .

Brianne Martino posted this image to the Facebook group “What’s Going on Saratoga?” a few days ago and the reaction was mostly unanimous; kill them before they destroy other trees.

The NYS DEC agrees and on their website they educate people on what to do during a seasonal infestation.

“When populations are low, or when you only have a few trees to protect, caterpillars and adult moths can be killed by crushing them,” according to the DEC. They add that some “egg masses can be destroyed by scraping them from trees or other structures and dropping them into a container of detergent.”

How to get rid of a large gathering of spongy moth caterpillars?

The DEC says that in mid-June, when the caterpillars are at their largest, a burlap trap can be placed around infested trees. For a tutorial on how to do this correctly, click here.