The short answer is "no" for trees in a forest setting, but "maybe" for individual landscape trees.
Combine the number and size of trees in a forest setting with the variety of tree species in a stand and the large number of insects that could be causing a problem. The additional complexity of matching the proper insecticide to the insect you want to control, along with the successful timing of the applications, demonstrates that broadcast spraying is not an environmentally, economically, or operationally sound management decision. On rare occasions, insect outbreaks over large tracts of forested land are treated with aerial applications of carefully selected insecticides for a specific insect on a specific tree species. The success of these projects is a topic much debated.
Individual landscape trees would be candidates for spraying once the attacking insect is identified and recommended chemical controls are selected. Even then, given the complex and varied nature of insect life cycles and the size and mass of a tree canopy, a broadcast spray program is only moderately successful in controlling insect outbreaks.
