- 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.