F-519570 
FIGURE 114.—Defoliation and 
webbing caused by _ the 
fall webworm, Hyphantria 
cuned. 
larvae are gregarious until the last instar. During the early in- 
stars they feed on the upper surface of the leaves; later they 
devour entire leaves excepting the larger veins and midribs. As 
they approach maturity, some of them leave the web and feed 
individually. Pupation occurs in thin cocoons usually spun in the 
duff or just beneath the surface of the soil. There are one or two 
generations per year, depending on location. 
The fall webworm is ordinarily of no great importance as a 
forest pest since it usually attacks understory, weed species of 
no economic value. Outbreaks may occur, however, sometimes en- 
compassing tracts several miles in extent. It is often a serious 
pest of shade trees and ornamentals. These trees may not only be 
heavily or completely defoliated, but the presence of numerous, ~ 
unsightly webs detracts greatly from their esthetic value. Oliver! 
discussed the ecology of the species in the Deep South, and (575) 
its natural and biological control in Louisiana. Tothill (715) dis- 
cussed its natural and biological control in Canada. 
Seirarctica echo (J. E. Smith) larvae feed on the foliage of 
persimmon, ground oak, and sabal palmettos from Florida to 
Mississippi. The adult is white and has a wingspread of about 
55 mm. The wing veins are edged with dark brown or black. Full- 
grown larvae are clothed with coarse, black-tipped hairs and are 
about 50 mm. long. The body is black on top except for a pair of 
yellowish stripes and a row of orange-colored warts that cross 
each segment. 
Other species of arctiids likeiy to be encountered in eastern 
forests include: Haploa clymene (Brown)—on maple, hickory, 
and apple; H. lecontei (Guer.)—on maple, birch, oak, and cherry; 
Apantesis radians (Wlk.)—on slash pine seedlings in Georgia; 
and Lexis bicolor Grt—on balsam fir and spruce. 
1! Oliver, A.D. 1963. An ecological study of the fall webworm, Hyphantria 
cunea (Drury), in Louisiana. PhD Thesis, Louisiana state Univ. 
307 
