Thirteen insecticides were tested in a laboratory spray chamber on 4th and 5th instar hemlock sawfly, Neodriprion tsugae Middleton. Twelve exceeded DDT in toxicity at both LD50 and LD90. At LD50 the descending order of toxicity to combined groups of 4th and 5th instars was tetrachlorvinphos, resmethrin, fenitrothion, naled, mexacarbate, malathion, pyrethrins, dimethoate, propoxur, carbaryl, methomyl, trichlorfon, and DDT. Of 6 insecticides applied topically to 4th- and 5th-instar western hemlock looper, Lambina fiscellaria lugubrosa (Hulst), 5 exceeded DDT in toxicity at both LD50 and LD90. At LD50 the descending order of toxicity was pyrethrins, phoxim, mexacarbate, Dowco 217 (dimethyl-3,5,6-trichloro-2-pyridyl phosphate), fenitrothion, and DDT.
Document Type: Research Article
Publication date: April 1, 1975
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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.