Orgyia leucostigma

White-marked tussock moth
Adult
Caterpillar in Mississippi (June)
Conservation status
Not evaluated (IUCN 3.1)
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Lymantriidae
Genus: Orgyia
Species: O. leucostigma
Binomial name
Orgyia leucostigma
(JE Smith, 1797)
Synonyms
  • Phalaena leucostigma Smith, 1797
  • Hemerocampa leucostigma
  • Cladophora leucographa Geyer, 1832
  • Acyphas plagiata Walker, 1855
  • Orgyia wardi Riotte, 1971
  • Orgyia oslari Barnes, 1900
  • Orgyia libera Strecker, 1900

Orgyia leucostigma, the White-marked tussock moth, is a moth in the family Lymantriidae. The caterpillar is very common especially in late summer in eastern North America, as far west as Texas, Colorado, and Alberta.

Contents

Life cycle

There are two or more generations a year in eastern North America (Wagner 2005). They overwinter in the egg stage.

Eggs

Eggs are laid in a single mass over the cocoon of the female, and covered in a froth (Wagner 2005). Up to 300 eggs are laid at a time.

Larvae

The larvae are brightly coloured, with tufts of hair-like setae. The head is bright red, the body has yellow or white stripes, with a black stripe along the middle of the back. There are bright red defensive glands on the hind end of the back. Four white toothbrush-like tufts stand out from the back, and there is a grey-brown hair pencil at the hind end. Touching the hairs will set off an allergic reaction in many humans (Wagner 2005). Young larvae skeletonize the surface of the leaf, while older larvae eat everything except the larger veins (Rose and Lindquist, 1982). They grow to about 35 mm.

Pupae

The caterpillars spin a grayish cocoon in bark crevices and incorporate setae in it (Rose and Lindquist, 1982). The moths emerge after 2 weeks.

Adults

The females have reduced wings and do not leave the vicinity of the cocoon. The males are grey with wavy black lines and a white spot on the forewings. (The vapourer, Orgyia antiqua, is similar but is a rusty colour.) The antennae are very feathery. Moths are found from June to October.

Host plants

The caterpillars may be found feeding on an extremely wide variety of trees, both deciduous and coniferous, including apple birch, black locust, cherry, elm, fir, hackberry, hemlock, hickory, larch, oak, rose, spruce, chestnut, and willow (Wagner 2005). Defoliating outbreaks are occasionally reported especially on Manitoba maple and elm in urban areas (Rose and Lindquist, 1982). Outbreaks are usually ended by viral disease.

Ecology

The fungus Entomophaga maimaiga was introduced to North America to control the gypsy moth Lymantria dispar. The fungus also infects O. leucostigma (Hajek et al., 2004) and could possibly have an impact in years when E. maimaiga is abundant. Large larvae are mostly attacked by birds, and small larvae mostly disappear during dispersal (Medina and Barbosa, 2002).

Subspecies

References

External links