This pictorial describes how western spruce budworm larvae feed on young western larch and the trees' responses to this damage. Larvae feed not only on the current year's foliage-their usual diet on most coniferous hosts-but also sever stems of current year's shoots. Multiple-topped, bushlike trees develop in direct response to the amount and type of damage. As a result, trees cannot maintain straight boles and good form. Sustained budworm damage could conceivably influence the management of western larch-one of the more important conifers in the northern Rockies.
Fellin, David G.; Schmidt, Wyman C. 1973. How does western spruce budworm feeding affect western larch? Gen. Tech. Rep INT-GTR-7. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 25 p.