Do It Yourself
In small numbers, budworms can be hand picked from a young evergreen tree or shrub. Another trick is to prune and destroy the infested shoots.

Natural Insecticide
Spray infested trees with Bt (Bacillus thuringiensis) as the buds burst in spring. Tests in eastern Canadian forests showed an 80 percent mortality rate of spruce budworms in trees sprayed with Bt. Remember to reapply Bt after rains. For detailed information see the file about Bacillus thuriengensis

Synthetic Insecticide
Use a pyrethroid insecticide according to the label on the container. For information about your choices see the files on Synthetic Insecticides for Trees and Shrubs