In forest areas sprayed with DDT. population trends of a western spruce budworm, Choristoneura occidel1talis Freeman, its parasites, and associated defoliators were followed from 1951 until 1959. Budworm populations were reduced to low levels by the spraying. but oscillations in numbers were detectable by sampling. A major peak in numbers on sprayed areas occurred in 1954 in the western Cascade Range and in 1955 in the Blue Mountains, with a lesser peak in 1957 in all areas studied. Parasitism of small larvae either increased slightly or was the same, 1 or 2 years after spraying, and in subsequent years was similar to that before spraying. Parasitism of large larvae I year after spraying varied. but in some areas was high; in the Blue Mountains highest parasitism was often caused by parasites considered of minor importance in unsprayed areas. In a related study following spraying in 1958, 3 associated defoliators, Zeiraphera hesperiana Mutuura & Freeman, Griselda radicana (Walsingham), and Argyrotaenia dorsalana (Dyar) showed markedly better survival than the western budworm.
Document Type: Research Article
Publication date: February 1, 1971
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.