The ailanthus silkmoth (Samia cynthia) is a saturniid moth, used to produce silk fabric but not as domesticated as the silkworm, Bombyx mori. The moth has very large wings of 113-125 mm, with a quarter-moon shaped spot on both the upper and lower wings, whitish and yellow stripes and brown background. Eyespots on the outer fore wings. Common name of 'Ailanthus silkmoth' refers to the host plant.
Asia: Russian Far East, northeastern China as far south as Zhejiang, and Japan. Escaped from cultivation or introduced and naturalized in North America on the east coast,and France, Italy, Switzerland, Hungary, Austria, Croatia and Uruguay.
Whitish eggs, marked with brown, are laid in rows of 10 to 20 on leaves in crescents. Hatching takes 7-10 days.
Larvae are gregarious and yellow at first. Later instars are solitary, and whitish-green with white tubercules along the back, and small black dots. 5 instars, maximum length 70-75 mm.
A silken off-white to grey cocoon is spun on the leaves of the host. It has an obvious escape hatch.
Females call in the evening or night after emerging in late morning. Adult flight is during May and June in northern Europe, as one generation. In southern Europe a partial second generation may occur in September.
Tree of heaven
Larvae will feed on other trees, but all eggs are laid on Ailanthus
and growth is best on it. This tree is commonly grown as an ornamental in cities.
Tuskes, PM, JP Tuttle and MM Collins. 1996. The wild silk moths of North America. Cornell University Press. ISBN 0-8014-3130-1
Saturnids of Western Palearctic