Species Lymantria dispar - Spongy Moth - Hodges#8318

8318

Gypsy Moth - formally discontinued by ESA as inappropriate, officially replaced in March 2020

Lymantria dispar (Linnaeus, 1758)

Phylogenetic sequence # 930141

This is the only Nearctic species in the genus, an introduction from the Old World.

Males typically have a wingspan of 38 mm, while for females the wingspan is somewhat larger.

"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)

The female is mostly light-colored and is too heavy to fly. The males are slightly smaller and dark with wavy lines.

Native to Eurasia, introduced to North America at Boston, Massachusetts circa 1869 and has been spreading ever since (US Forest Service). 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, Lymantria dispar is present in British Columbia and in much of eastern Canada.

Many hardwood species. A very partial list includes Red Oak, Cherries, Willows, Hickories, and Pines. Over 500 spp. of plants are known hosts.

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.

Newborn larvae......early instar......late instar:

Pupa......................male.......................female......................egg-laying female:

Etienne Leopold Trouvelot, an amateur entomologist, brought Lymantria dispar 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.

A parasitic tachinid, Compsilura concinnata, was introduced in the US as a biocontrol. Unfortunately, it also parasitizes many native moths (Fuester et al., 2001). Several other biological controls have also been introduced with varying degrees of success (Kenis & Vaamonde, 1998).

Ferguson, D.C., 1978. The Moths of America North of Mexico, Fascicle 22.2. The Wedge Entomological Research Foundation, p. 90; pl. 1.9-12. (1)

Powell, J.A. & P.A. Opler, 2009. Moths of Western North America. University of California Press, pl. 49, figs. 9, 10; p. 274. (2)