The Delaware Forest Service encourages Delawareans to keep their eyes out for spongy moth egg masses this spring.
Formerly known as gypsy moth, the spongy moth is an invasive insect that can be found in Sussex County.
Delaware Forest Service Forest Health Specialist Bill Seybold says in their caterpillar stage, these moths tend to eat all or most of the leaves on hardwood trees.
“It doesn’t kill the trees, it defoliates them. Takes their leaves off during an important time of year in June when they need their leaves to make food for the tree. But healthy trees don’t die from one or two years of defoliation,” Seybold explained.
And he adds that in their caterpillar stage, spongy moths can be a cause of concern for anyone.
“They’re typically a concern for the woodland owner who has a lot of oak trees in their forest who may be getting slower growth or some mortality from the defoliation of the leaves. And for the background homeowner it causes a lot of upset, and aesthetic concerns, of course,” he said.
Come late spring, decks can be covered in caterpillars. And for a small percentage of people, the bugs can cause skin irritation or allergy when touched
The best way to prevent these caterpillars from causing any damage is for residents to start going out on dry days between now and late April to look for egg masses on the trunks and undersides of main branches of hardwood trees.
Fresh egg masses are yellow-brown, intact, and firm to the touch.
Last year’s outbreak was largely in the Cypress Swamp and Nanticoke State Wildlife areas in Sussex County, but residents should also look in areas where spongy moth caterpillars or defoliation was seen during the growing season.
Any egg masses found should be scraped into soapy water.
If the masses are too high up in the tree or too abundant, residents should call the Forest Service at (302) 698-4553.
The number of spongy moths have not warranted intervention from the Forest Service in recent years, but Seybold says their population could continue to grow. In 2022 increased spongy moth activity was detected.
While residents should stay vigilant, Seybold says its his hope that natural viral and fungal pathogens, which have stopped past outbreaks, return before the issue progresses.
