History of TM BioControl-l: The first registered virus-based product for control of a forest insect

Abstract

The Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae) (Fig. 1), is a defoliator of significant importance in Douglas-fir and true-fir forests of western North America. Outbreaks of this insect have occurred in many regions, from British Columbia to Arizona and New Mexico, and from the Rocky Mountains to the Cascade and Siskiyou ranges of Washington, Oregon, and California. Since the first reported infestation at Chase, British Columbia, in 1916, several major outbreaks have occurred in stands where conditions changed rapidly in favor of tussock moth survival. Prominent among these outbreaks: in Idaho, 447,000 acres from 1944 to 1947,225,000 acres from 1961 to 1965, and 110,000 acres from 1971 to 1974; in Oregon, 438,000 acres from 1971 to 1974; and in Washington, 251,000 acres from 1971 to 1974.