Numbers
This is the only Nearctic species in the genus.
Size
Males typically have a wingspan of 38 mm, while for females the wingspan is somewhat larger.
Identification
"The larval stage (caterpillar) is hairy, and a mature larva is 50-65 mm long with a yellow and black head. Behind the head on the thorax and abdomen are five pairs of blue spots (tubercles) followed by six pairs of brick red spots."(from Penn State website) Please note: earlier instars (under about 12mm) do not exhibit the characteristic blue and brick red pairs of tubercles, nor the yellow and black head. Look instead for "first thoracic segment with prominent subdorsal warts bearing numerous long setae that makes face look "eared." "(Caterpillars of Eastern Forests)
Range
Michigan, Pennsylvania, and all states to the north and east of these. Also much of Wisconsin. Also the northern parts of Illinois, Indiana, and Ohio. Most of West Virginia is included in the insect's range, as well as parts of Virginia and North Carolina. The United States Forest Service estimates the moth's range is spreading south and west at a rate of about 21 kilometers per year. In Canada, the Gypsy Moth is present in British Columbia and in much of eastern Canada.
Food
Many hardwood species. A very partial list includes Red Oak, Cherries, Willows, Hickories, and Pines. Over 500 spp. of plants are known hosts.
Life Cycle
In late summer females lay up to 1,000 eggs per egg mass. The eggs overwinter and hatch in the Spring. Larvae feed heavily and do considerable damage to forests. Pupation typically occurs in mid-Summer.
Remarks
The female is mostly light-colored and is too heavy to fly. The males are slightly smaller and dark with wavy lines.
Etienne Leopold Trouvelot, an amateur entomologist, brought Gypsy Moths into the United States to see if they could be successfully reared for silk culture. Around 1869 some of Trouvelot's charges escaped from his home near Boston. Realizing the potential magnitude of the problem, he reported the escape but no action was taken until the infestation grew serious several years later. Trouvelot later became interested in astronomy and astronomical illustration, and eventually became a Harvard professor of Astronomy.
