Webworm, Hyphantria cunea (Drury)

Importance. - The fall webworm is considered an important forest pest. However, ugly webs can seriously detract from aesthetic
values, and they can quickly defoliate a tree. The preferred hosts in the South are persimmon, pecan, and Live Oak.

Identifying the Insect. - The adult moth has a wingspan of 1 (25 mm) to 1 1/4(31 mm) inches and is snowy white, usually with dark
spots on the wings. The larvae are 1 (25 mm) to 1 1/4 (31 mm) inches long and covered with silky hairs. The color varies from pale
yellow to green, with a black stripe on the back and a yellow stripe on each side. The pupae are found inside a gray cocoon
constructed of silk, frass, and debris. The eggs are small, yellow, or light green, and turn gray before hatching.

Identifying the Injury. - Usually the first signs of attack are the large, silken web and skeletonized leaves. The silken web usually
contains large numbers of caterpillars. Defoliation can quickly occur.

Biology. - The moths emerge in the spring. After mating, females lay eggs in masses (400 to 500) on the undersides of host leaves.
The eggs hatch in approximately 2 weeks, and the larvae immediately begin to feed and construct webs. They enlarge the web as
they continue to feed for 4 to 8 weeks. Then they spin a pupal cocoon in a sheltered place or in the duff or soil. There are at least
two generations per year in the South.

Larva. Typical damage showing large tents.

Control. - Biotic agents, and unfavorable weather take their toll of these insects. Chemical control may be

necessary. Contact your Tree Masters Arborist for more advice.