Lymantria dispar (Lymantriidae)

gypsy moth

Adults:

Lymantria dispar, the gypsy moth, adult female; the female is nearly white and larger than the male.

Lymantria dispar, the gypsy moth, adult male; the male is brown, smaller than the female, and has bipectinate antennae. 		A rather large moth with a wingspan of about 5 cm. The male is dark brown and the female nearly white with wavy dark-coloured bands across the forewings.


Pupae:

Lymantria dispar pupa. Dark reddish-brown with a few yellowish hairs.


Larvae:

Lymantria dispar larva (caterpillar). Larvae emerge from the eggs during April-May. Mature larvae are 6 - 71/2 cm long, dark in colour and hairy. They are recognizable by a double row of dots along the back, 5 pairs of blue and 6 pairs of red.


Eggs:

Lymantria dispar egg mass adhered to a surface, covered with hairs from the female moth. Newly hatched first-instar larvae can be seen. In clusters of up to 500 covered with buff-coloured hairs. In appearance the cluster resembles small pieces of chamois attached to the underside of branches, bark scales, rocks, houses, etc. This is the overwintering stage.


Damage:

Damage caused by gypsy moth larval feeding. Defoliation may result in tree mortality, growth reduction, and impairment of aesthetic values.


Principal Hosts:

Larvae will feed on more than 100 species of trees (usually hardwoods) and shrubs, although feeding may occur on softwoods in mixed stands.

Economic Importance:

The gypsy moth has been a serious problem in the eastern Canada and U.S. for over 100 years and now directly threatens western forests.

For background information about the diligent trapping survey programs and Btk treatment procedures that are in place in BC to prevent permanent establishment of the Gypsy Moth, see the BC Ministry of Forests' website, Gypsy Moth in BC. Be sure to visit the Gypsy Moth History Page.

References and Links:

EAG: 473-476; FC: 228.

For more information about the biology of L. dispar, see the first part of PFC Forest Pest Leaflet 75.

For a general account of the gypsy moth in BC from the Canadian Forest Service, plus linkages to pages about the gypsy moth threat and quarantine measures, see the second part of PFC Forest Pest Leaflet 75.

The Gypsy Moth, Lymantria dispar, in North America, is Sandy Liebhold's in-depth account of the origins and spread of the European gypsy moth in North America, its effects on forest vegetation as well as management options.

The Asian Gypsy Moth Project describes the efforts to control the moth in the Eastern USA.

Learn how eastern North America is limiting the spread of the gypsy moth through the Slow the Spread Project.

Additional Images:

summer defoliation pupae in rolled leaf new egg mass on bark