The contact toxlaty of 100 insecticides to last stage larvae of Choristoneura occidentalis Freeman was tested by topical application in a 10-yr series of screening experiments. Pyrethroids were generally the most toxic group of chemicals tested. Compounds more toxic than the standard, mexacarbate, at LD90 were: bioethanomethrin, (+) cis-resmethrin, (+) trans-resmethrin, (+) cis-phenothrin. ENT 29l17 (5-benzyl-3-furylmethyl (IR,3S,E) 2,2-dimethyl-3- (2-oxo-3-tetrahydrothiophenylidenmethyl) cyclopropanecarboxylate), resmethrin, and NRDC 143 (3-phenoxybenzyl (±)-3- (2,2-dichlorovinyl-2,2-dimethylcyclo-propanecarboxylate). Mexacarbate spray was tested on the western spruce budworm at selected developmental stages. First instal's were least susceptible at both LD50 and LD90; instal'S 3–5 and 6th instars weighing less than 110 mg were most susceptible. Since long-term laboratory realing of insects did not change their responses to 3 representative chemicals periodically tested during this series of experiments, the results represented a valid estimate of relative toxicity.
Document Type: Research Article
Publication date: February 1, 1976
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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.