If you live in the Northeast, Midwest, or Middle Atlantic states, you may have noticed an unwelcome visitor in your garden this spring: Spongy moths (formerly called gypsy moths). These voracious pests hatch out as teeny caterpillars starting in mid-to late spring, depending on where you live. “They can defoliate thousands of acres of forest,” says entomologist Michael Skvarla, PhD, assistant research professor of arthropod identification at Penn State University. “They have only one generation per year, so they’re usually done hatching by early June.”
From the time they emerge, they’re eating your garden. They chow down on more than 500 different plants, though their favorites are trees such as oak, aspen, birch, cedar, willow and all kinds of fruit trees. “They avoid foods they don’t especially like, such as catalpa and dogwood, but once preferred foods are gone, they’ll switch to plants they don’t like. Once those are gone, they’ll eat plants they avoid in other situations, such as conifers,” says Skvarla.
While some years you barely notice these insects, a significant outbreak occurred in the summer of 2021 and has continued this year. So, is your garden doomed?