There are well over 1,000 species of moths in New England. Most of them are native and pose no threat; many are quite beautiful. Unfortunately the few bad actors, give the benign majority a bad image. Here are a some of the conspicuous moth species that defoliate trees–sometimes extensively.
(Operophtera brumata) This invasive insect can wreak havoc on our trees. Introduced into the United States from Europe via Canada, is most commonly observed in late fall, early winter as a white adult moth and in spring as a tiny green caterpillar. Learn More
Spring and Fall Cankerworms
(Paleacrita vernata and Alsophila pometaria). Though native, these two species are very similar to the winter moth (as well as to each other) in both appearance (caterpillars and adults) and in behavior. They are “irruptive” and in certain years can cause serious defoliation over large areas.
(Lymantria dispar). A Eurasian species accidentally introduced in Massachusetts in 1869, it defoliates hundreds of acres of forests from New England west to Michigan and south to Virginia, and also on the west coast from California to British Columbia. Feeding mainly at night, later stage caterpillars descend from the treetops to cluster on tree trunks by day where they are less vulnerable to predators. Learn More
Eastern Tent Caterpillar
(Malacosoma americanum). A native species, it makes a silken nest in the crotches of cherries, apples, and other trees in the rose family. Tent caterpillars hatch early (about mid-April) and become conspicuous by May when they begin spinning the silken “tents” for shelter. They feed on leaves outside the web and return for shelter from predators and warmth on cool days. Damage is mainly to ornamental trees, and these typically re-foliate once the caterpillars have abandoned the tent.
(Hyphantria cunea). Unlike the eastern tent caterpillar, this native species pitches its tent over entire branches –sometimes entire trees–rather than enveloping just the crotches. The caterpillars feed on the leaves inside the web, extending it as necessary. They are known to feed on over 400 species of woody plants. As the name implies, the webs appear in late summer and fall. The effect of an infestation is mainly aesthetic and limited in area with no lasting damage to healthy trees. Learn More