The fruittree leafroller, A. argyrospilus (Walker), occurs throughout the United 
States and from coast to coast in southern Canada. Its hosts include many fruit trees 
and many forest and shade trees such as ash, hickory, elm, oak, maple, walnut, 
poplar, birch, basswood, and buckeye. The adult is pale yellow to orange-red and 
has a wingspread of about 21 mm. The forewings are mottled with golden scales, 
their tips triangular. The hindwings are fuscous and have dirty-white fringes. Full- 
grown larvae are light green and about 22 mm long. 
Adults are present from June to August, depending on location. Eggs are 
deposited in small, round or convex masses containing about 100 to 150 eggs each, 
usually on twigs or small branches. Winter is spent in the egg stage, and hatching 
occurs in early spring. Young larvae feed on opening buds, blossoms, young fruit, 
and unfolding leaves which they web together with silk. Later, several leaves may 
be webbed together, forming a nest in which the larvae live and from which they 
move out to feed. Pupation occurs in flimsy cocoons spun inside the nest or on the 
branches or trunk of the tree. A number of outbreaks of this species, some of which 
covered tens of thousands of hectares, have occurred in oak stands in Eastern and 
Lake States. 
Archips semiferanus (Walker) defoliated oaks on more than 400,000 hectares in 
midcontinent areas (375, 1/330). Northern red, scarlet, and northern pin oaks of all 
ages are affected. The adult is light olive brown with a diagonal rusty band on the 
forewing; the wingspread is about 22 mm. Mature larvae are greenish yellow and 
about 21 mm long. Masses of I5 to 125 eggs covered with tan scales from the 
female’s abdomen are deposited on the bark of tree crowns during July and early 
August. Hatching occurs the following spring, in mid-May, about the time of 
Courtesy Conn. Agric. Exp. Stn. 
Figure 57.—Nest of larvae of the oak webworm, Archips 
fervidanus. 
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