A laboratory culture or organophosphorus-susceptible boll weevils was exposed at different temperatures to cot- ton leaves or filter-paper discs previously treated with insecticide or defoliant. All materials examined showed a positive temperature coefficient of toxicity with methyl parathion and malathion being the most toxic at all temperatures. The toxicities of azinphosmethyl and EPN®(O-ethyl O-p-nitrophenyl phenylphosphonothio- ate) were severely decreased at 1O°C while DEF® (S,S,S- tributyl phosphorotrithioate) showed appreciable toxicity only at 32°C. Studies involving different exposure and holding temperatures indicated that a higher exposure temperature results in increased toxicity, even though the holding temperature is the same for all treat- ments. Although transferring the insects to a low hold- ing temperature from a high exposure temperature decreased the effectiveness of the toxicant, the corrected mortality of the insects exposed at 32®C and held at 10®C was more than twice that of those exposed and held at 10®C. These data suggest that temperature may affect both the innate toxicity and the rate of absorption of the insecticide into the insect.
Document Type: Research Article
Publication date: April 1, 1970
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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.