The insect overwinters as an egg which hatches in the spring about the time amelanchier blossoms. The larvae move up the tree then suspend themselves from a thread that allows them to be carried by the wind to other trees. The larvae feed for about 7 weeks then pupate in a sheltered place. The moths emerge in mid-summer. The females do not fly but give off a chemical that attracts males that can fly. After mating the female lays eggs and the adults die without feeding.
The young larvae are dark colored and hairy. The older larvae can be 2 1/2 inches long, dark colored with faint white stripes running the length of the body. There will be a series of blue or red spots at the base of tufts of hair. The adult moths are quite different in appearance. The female is white with tan stripes across the wings and small V shaped brown marking. The male is mottled brown.
The insects injure plants by eating the leaves. The preferred hosts are apple, linden or basswood, hawthorn, oaks, poplar and willow. Plants rarely attacked are ash, balsam fir, butternut, black walnut, catalpa, red cedar, dogwood, holly, locust, sycamore and yellow poplar.
Control is difficult since the insects are so numerous. The insects are often spread when egg masses are laid on cars or trucks and then carried some distance. Spraying may protect individual plants but it will have to be done each year. Repeated defoliation will kill the favored hosts.
Pesticides labeled for gypsy moth are methoxychlor, Sevin, Orthene, or Bacillus thuringiensis.
|Visual title - Visual size||Visual title - Visual size|
|Gypsy moth egg mass - 53K||Gypsy moth larvae - 40K|