Eastern Tent Caterpillar nest - picture by Bart Fusco

Eastern Tent Caterpillar nest – picture by Bart Fusco

Once again we’re seeing an outbreak of tent caterpillars in various areas of Long Island, including the east end. Their preferred hosts are cherry trees, but they will go after a variety of other trees, including crabapples, dogwoods and others You can see their “tent” webs in the crotches of affected trees. They feed on leaves and can defoliate areas of their hosts. Although not as voracious or dangerous as gypsy moth caterpillars (for which they are often mistaken) they can seriously harm the look of a tree for the rest of the growing season. We highly recommend early treatments of these insects, right now, to prevent damage. Early treatments can be made with reduced-risk “organic” treatments, such as bacillus thuringiensis based materials like Foray XG.

Eatern tent caterpillars overwinter as an egg mass which looks like shiny, dark foam and are found around pencil-sized twigs. Larvae come out and start feeding at the same time cherry leaves emerge in late spring to early summer and this is when damage begins. They can be differentiated from gypsy moth caterpillars a unique white stripe running across the length of the back. Gypsy moths and forest tent caterpillars don’t have a white stripe.

The caterpillars stay together after hatching, move to a branch crotch and spin a silk web in order to make a white tent. The tent shelters them from weather and heat and also hides them from predators. They don’t feed while in the tent, but then migrate from tent to tree to begin feeding, leaving a silk trail for other caterpillars to follow.

After pupating, adult moths emerge and mate, and females lay eggs in July and August which then overwinter. Adults do not feed. There is one one generation annually.

Fox Tree is out treating the emerging caterpillar right now, using reduced-risk treatments wherever possible. Contact us right away to arrange treatment to your trees and avoid damage now!