• Desaulniers, Real
  Entomology and Pathology Service
  

The economy of Quebec is based for the main part on its forest resources. The two main species are Balsam Fir and White Spruce. Periodically, we have epidemics of the Spruce Budworm, a lepidopterous insect which feeds during its larval stage on the new foliage of Spruce and Fir. The trees usually die after four consecutive years of severe defoliation, (destruction of fifty percent or more of the current years foliage), and not usable by the forest industry after four additional years.

On detecting such a vast and intensive epidemic of this inset in 1967, the Quebec Department of Lands and Forests and the Chemical Control Research Institute of the Canadian Environment Ministry, under took joint research in techniques of aerial insecticide spraying in 1971. This culminated with a new method of apply insecticide with four engine tanker aircraft. This method required new formulations and new types of insecticides mixing plants. Furthermore the high speed aircraft used necessitated a more accurate guidance system than the "navigation by eye" system used with single engine planes.