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Hosts:
The fall webworm is known to feed on more that 100 species of forest and shade trees. 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 attacked. In the west, alder, willow, cottonwood and fruit trees are commonly attacked.
Evidence: Adult moths
have a wingspan of between 1.4-1.7 inches (35-42 mm). The bases of the front legs are orange or bright yellow. In the southern part of its range, the moth is white with dark wing spots while in the Northern part of its range it is nearly always pure white and was once thought to be a separate species. Adults appear mostly from May to August and deposit their eggs in hair-covered masses of several hundred each, usually on the underside of host leaves.
Larvae
are usually pale yellowish-greenish, with a broad, dusky strip down the back and a yellowish stripe down each side. Full grown larvae may reach a length of 1 inch or more (25 mm). Larvae are covered with long, silky gray hairs arising in tufts from orange-yellow or black tubercles: head color varies from red to black. Newly hatched larvae immediately spin a silken web over the foliage on which they feed. As larvae grow, they enlarge the web to enclose more foliage. On heavily infested trees, several branches may be enclosed in webs. Occasionally, small trees may be completely encased in webbing. Larvae are gregarious until the last instar when they leave the web and feed individually. Pupation occurs in thin cocoons usually spun in the duff or just beneath the soil.
Damage: Though the webs are unsightly, damage to most trees is considered to be insignificant. However, in areas where multiple generations attack and heavily defoliated trees, including
in pecan production areas, control measures may be needed. Contact your local county extension office for appropriate control strategies if needed. |
