The webs produced by the fall webworm, _Hyphantria cunea_ (Drury), are
familiar to everyone. Leaves are eaten by the larvae which live in
loosely woven, dirty white webs, Figure 19.
The adult is a white moth which may have black or brown spots on the
forewing. Its wings have a span of about 1 inch.
The larvae are pale yellow spotted with black. They attain a length of 1
inch when full grown and are covered with long black and white hairs.
The insect overwinters as a pupa in lightly woven cocoons in debris on
the soil or under the bark. In the spring the adults emerge and lay
masses of greenish white eggs on the leaves. The caterpillars which
hatch from the eggs feed on the leaves in colonies under webs which they
construct. After feeding for a month to 6 weeks, the larvae crawl down
the tree and pupate in loose cocoons in debris, under bark, or in loose
soil. Adults appear during the summer and deposit eggs for the second
generation. The larvae of this generation feed extensively until fall,
crawl down the tree and pupate for the winter.
_Control._—Light infestations on a few trees can be eliminated by
pruning out the affected branches and burning them. If this method of
control is not practicable, the trees should be sprayed with 2 pounds of
50 percent DDT wettable powder; 1 pound of 25 percent parathion wettable
powder; or 3 pounds of lead arsenate per 100 gallons of water[9].
[Illustration: Figure 19. Web of the fall webworm on a pecan limb.]