Orgyia leucostigma

The genus name Orgyia is from the ancient Greek word , órgyia - 'outstretched arms'. So named because, when at rest, the moth stretches forward its forelegs like arms. ==Life cycle==

Two or more generations occur per year in eastern North America. Touching the hairs sets off an allergic reaction in many humans. They grow to about 35 mm long. Pupae The caterpillars spin a grayish cocoon in bark crevices and incorporate setae in it. The moths emerge after two weeks. Adults The females have reduced wings and do not leave the vicinity of the cocoon. The males are gray with wavy black lines and a white spot on the forewings (the vapourer, Orgyia antiqua, is similar but is a rusty color.) The antennae are very feathery. Moths are found from June to October. Orgyia leucostigma-female eggs.jpg|Wingless female with eggs ==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. Defoliating outbreaks are occasionally reported especially on Manitoba maple and elm in urban areas. Outbreaks are usually ended by viral disease. ==Ecology==

The fungus Entomophaga maimaiga was introduced to North America to control the spongy moth (Lymantria dispar). The fungus also infects O. leucostigma 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. ==Subspecies==

• O. l. leucostigma (South Carolina, from Georgia and Florida to Texas) • O. l. intermedia Fitch, 1856 (from Maine and Ontario to Virginia, Alberta and Kansas) • O. l. plagiata (Walker, 1855) (Nova Scotia, New Brunswick, Quebec) • O. l. oslari Barnes, 1900 (New Mexico, Colorado) • O. l. sablensis Niel, 1979 (Sable Island, Canada) ==Image gallery==

File:Hand holding a Willow Leaf with a White-Marked Tussock Moth.jpg|Larva File:Orgyia leucostigma Pupae stage - 1.jpg|Larva File:Orgyia leucostigma Pupae stage - 2.jpg|Larva File:Orgyia leucostigma Pupae stage - 3.jpg|Larva File:Orgyia leucostigma Pupae stage - 4.jpg|Larva File:Orgyia leucostigma Pupae stage - 5.jpg|Larva File:Orgyia Leucostigma caterpillar Michigan.jpg|Caterpillar File:Orgyia leucostigma caterpillar 2017 April 16 Texas.jpg|Caterpillar in Texas ==References==