- Stipe, Lawrence E.
United States Department of Agriculture, Forest Service, Cooperative State Research Service
The western spruce budworm has an annual life cycle of four stages--egg, larva, pupa, and adult (moths). The stages, damage caused by budworm, and host species are described and illustrated in Forest Leaflet 53 by Fellin and Dewey (1982).
Ground sprays will reduce current defoliation and cone damage by budworm larvae and help maintain tree vigor, thus minimizing permanent damage to trees. The strategy is to time the application of the control agent for maximum kill of the insect pest with the least effect on the environment. Cone and seed protection using ground applications has increased Douglas-fir seeds yields by nearly 50 percent. Further tests are needed to determine the value of this technique on other species (Stipe and Green 1981). Equipment operated at ground level us used to apply the spray mixture to the foliage when insect larvae are actively searching and feeding. control during other life stages (for example, moths) is not recommended.