Orgyia leucostigma
Encyclopedia
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
.
s 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.
e 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.
in urban areas (Rose and Lindquist, 1982). Outbreaks are usually ended by viral disease
.
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).
Lymantriidae
Lymantriidae is a family of moths. Many of its component species are referred to as "Tussock moths" of one sort or another. The caterpillar, or larval, stage of these species often has a distinctive appearance of alternating bristles and haired projections...
. The caterpillar is very common especially in late summer in eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, as far west as Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, and Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
.
Life cycle
There are two or more generations a year in eastern North America (Wagner 2005). They overwinter in the egg stage.Eggs
EggEgg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s 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 larvaLarva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e 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 elmElm
Elms are deciduous and semi-deciduous trees comprising the genus Ulmus in the plant family Ulmaceae. The dozens of species are found in temperate and tropical-montane regions of North America and Eurasia, ranging southward into Indonesia. Elms are components of many kinds of natural forests...
in urban areas (Rose and Lindquist, 1982). Outbreaks are usually ended by viral disease
Animal virology
The study of animal viruses is important from a veterinary viewpoint and many of these viruses cause diseases that are economically devastating. Many animal viruses are also important from a human medical perspective...
.
Ecology
The fungus Entomophaga maimaiga was introduced to North America to control the gypsy mothGypsy moth
The gypsy moth, Lymantria dispar, is a moth in the family Lymantriidae of Eurasian origin. Originally ranging from Europe to Asia, it was introduced to North America in the late 1860s and has been expanding its range ever since...
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
- Orgyia leucostigma leucostigma (South Carolina, from Georgia and Florida to Texas)
- Orgyia leucostigma intermedia Fitch, 1856 (from Maine and Ontario to Virginia, Alberta and Kansas)
- Orgyia leucostigma plagiata (Walker, 1855) (Nova Scotia, New Brunswick, Quebec)
- Orgyia leucostigma oslari Barnes, 1900 (New Mexico, Colorado)
- Orgyia leucostigma sablensisOrgyia leucostigma sablensisOrgyia leucostigma sablensis is a subspecies of Orgyia leucostigma found only on Sable Island in Nova Scotia, Canada.-Physical:O. l. sablensis shares many common characteristics with its mainland counterpart, O. l. plagiata. Males and females of O. l. sablensis share the same antennae, palpi,...
Niel, 1979 (Sable IslandSable IslandSable Island is a small Canadian island situated 300 km southeast of mainland Nova Scotia in the Atlantic Ocean. The island is a year-round home to approximately five people...
, Canada)
External links
- http://bugguide.net/node/view/521/bgimage Images of adults and larvae
- http://eny3541.ifas.ufl.edu/Tussock/Orgyia.htm Telling apart 3 Orgyia species