Western Hemlock Looper
From Bugwoodwiki
Hagle, S.K; S. Tunnock; K.E. Gibson; and C.J. Gilligan. 1987. Field Guide to Diseases and Insect Pests of Idaho and Montana Forests. U.S. Department of Agriculture, Forest Service. State and Private Forestry, Northern Region. Missoula, Montana. Reprint 1990. Publication Number R1-89-54.
Contents |
Hosts
Western hemlock, true firs, and Douglas-fir.
Distribution
May be found anywhere hosts are found.
Damage
Larvae feed mostly at the base of needles and usually cut them off. Both old and new foliage are destroyed and mature larvae will feed on buds and tender shoots. This complete destruction of tissue can kill trees in I year.
Identification
Look for typical "inch worm" type larvae on needles from June to August. Mature larvae are about 1-3/8 inches long, green to brown in color with diamond-shaped markings on their backs (fig. 102). Heavy populations can cover a whole forest with silken webs. In late summer a greenish-brown pupa is formed in protected places and is not readily observed. Adults are tan-colored moths with two dark wavy lines on forewing and one on hind wing and are seen from September through October. Blue to gray-green eggs are laid singly on branches or botes in late September or October. Winter is passed in the egg stage.
Similar damages
Damage on hosts may be similar to other defoliation, but insect is distinct.
References
- Anonymous. 1982. For. Insect & disease identification and management. USDA For. Serv., Northern Region; Idaho Dept. of Lands, Insect and Disease Control; Montana Dept. of State Lands, Division of Forestry. 192 p.
- Furniss, R.L., and V.M. Carolin. 1977. Western For. Insects. USDA Forest Serv., Misc. pub. 1339, 654 p., illus.
