• Randall, A. P.
  Forest Pest Management Institute
  
• McFarlane, J. W.
  Forest Pest Management Institute
  
• Zylstra, B.
  Forest Pest Management Institute
  
• Desaulniers, R.
  Ministere Des Terres Et Forests Service D'Entomologie Et De Pathologie
  

A large-scale operational field trial utilizing thee applications of chemical insecticides and covering 120,960 hectares (298,000 acres) was conducted in 1977 to percent severe defoliation of balsam fir (Abies balsamea [L.] Mill.) red spruce (Picea rubens Sarg.) and black spruce (Picea mariana [Mill.]) in the Gaspe region of Quebec. Egg mass surveys in 1976 indicated unprecedented levels (2800+ egg masses/10 sq. meters of foliage), thus posing the problem of forest resources protection under abnormal conditions of pest populations. Two treatments of oil-formulated fenitrothion were applied at 0.28 kg AI/ha (4 oz AI/ac) to reduce second and early third-instar stages of the spruce budworm. A third application of oil-formulated aminocarb was applied at 0.07 kg AI/ha (1 oz AI/ac) when the larval population had reached 25% fourth instar. All formulations were applied at 0.84 /ha (11.52 fluid oz (U.S.)/ac) using douglas DC-6B spray aircraft, incremental application technology and inertial guidance swath navigation.