LONG-TERM EFFECTS OF AERIAL APPLICATIONS OF VIRUS–FENITROTHION COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

Abstract

Spruce budworm infested stands of white spruce and balsam fir were aerially sprayed with an entomopox virus, a nuclear polyhedrosis virus (NPV), a low dose of fenitrothion, and the two virus–chemical insecticide combinations. Long-term assessment of the efficacy of the treatments showed that NPV + a low dose of fenitrothion suppressed the budworm population density particularly on balsam fir below that causing economic damage for 3 years due mainly to transmission of the virus from one generation to the next and maintenance of natural control agents in the population.