• Irland, Lloyd C.
  Maine Forest Service
  

An epidemic of spruce budworm, a native insect, expanded dramatically

in northeastern North America in the 1970's (Fig. 1). The prospect

of serious tree mortality induced forestry agencies to undertake massive

spraying programs to reduce tree mortality by killing budworm larvae.

This program reached staggering proportions in 1976, when more than 20

million acres were sprayed in Quebec, Maine, and New Brunswick (Table

1). Such widespread use of insecticides has triggered intense controversy

over the risks posed by insecticides in the forest environment, and over

possible risks to human health. Although the spray programs have prevented

widespread tree mortality, the need for repeated treatment over most

areas has fostered the view among many that the programs are ultimately

futile since they do not eradicate the infestation in a short time.

This paper reviews the economic importance of the spruce-fir forests

of northeastern North America, the potential impact of spruce budworm on

that forest, and the insecticides employed in these programs.