Eastern Tent Caterpillars Are Not Gypsy Moth Caterpillars.

ANNAPOLIS, Md.--(BUSINESS WIRE)--May 12, 1999--

Maryland Secretary of Agriculture Henry A. Virts, D.V.M., announced today that the weblike nests, or tents, that are appearing in Maryland's trees are eastern tent caterpillar nests and are not gypsy moths.

"Maryland Department of Agriculture personnel have received a number of calls from citizens concerned that the tents in their trees might signal an infestation with gypsy moths. We have reassured them that the white nests are actually the tents made by eastern tent caterpillars, which are not a serious pest," said Virts.

"Webs of the eastern tent caterpillar are a common sight in early spring throughout Maryland wherever wild cherry trees are abundant. The caterpillars make the unsightly webs in the forks of trees and hide in the webs at night. They feed on the leaves of the tree during the day," said Dr. Robert Rabaglia of the Forest Pest Management Section of the Maryland Department of Agriculture.

"Leaves of wild cherry trees are the caterpillars' favorite food, but they will feed on crabapple, hawthorne, peach, plum, beech, birch and willow leaves. In severe outbreaks, the caterpillars can defoliate one or several trees, but usually the trees fully recover," said Rabaglia.

"People often see the tents in their trees and think they have gypsy moth caterpillars, but the two species are very different. Gypsy moth caterpillars prefer the leaves of hardwood trees like oaks. They hatch two to three weeks later than eastern tent caterpillars and feed much longer, usually until the end of June or early July, before they pupate. The gypsy moth caterpillars' longer feeding season is one reason trees have trouble recovering from defoliation due to an infestation. The trees have much less time to put out new leaves and to replenish food supplies they expend when making new leaves," Rabaglia said.

Eastern tent caterpillars hatch very early in the spring, usually around the first of April in Eastern and Central Maryland. The caterpillars feed on leaves until May when they leave the nest and search for a place to pupate.

The small, brown adult moths emerge from the pale yellow cocoons in early summer to mate and lay eggs. The eggs are laid in a shiny black mass around the twigs of host trees and overwinter on the twig. There is only one generation each year, with about nine months being spent in the egg stage.

Eastern tent caterpillars are dark grey or black, have a white stripe down the middle of their backs and a row of light blue dots along each side. When people first begin noticing them, the caterpillars are about one and one half inches long. They may grow to about two inches long before they pupate.

For further information, contact Dr. Robert Rabaglia of the Maryland Department of Agriculture, 50 Harry S Truman Parkway, Annapolis MD 21401, 410/841-5922.