Fall Webworm Moth

Description:

The fall webworm, Hyphantria cunea, is a moth in the family Arctiidae known principally for its larval stage, which creates the characteristic webbed nests on the tree limbs of a wide variety of hardwoods in the late summer and fall. It is mainly an aesthetic pest, and is not believed to harm otherwise healthy trees. It is well known to commercial tree services and arboriculturists. The adult is mostly white in the north, but in the south, it may be marked with black or brown spots on the forewings like this spotting. It is quite 'hairy', and the front legs have bright yellow or orange patches. The underwings will have less marking than the forewings, and the abdomen often has a sprinkling of brown hairs. It has a wingspan of 35–42 mm.

Habitat:

The moth is native to North America, ranging from Canada to Mexico, and is one of the few insect pests introduced from North America into other continents. This one was photographed at a porch light at the edge of a southern deciduous forest in Edgefield County, SC.

Notes:

The fall webworm feeds on just about any type of deciduous tree, where leaves are chewed; branches or the entire tree may become defoliated. Worldwide, it has been recorded from 636 species, and is considered to be among the most polyphagous of insects. In the eastern U.S., pecan, walnut, American elm, hickory, fruit trees, and some maples are preferred hosts; in some areas persimmon and sweetgum are also readily eaten. In the west, alder, willow, cottonwood and fruit trees are commonly used.