An average dose of 63.5g/1000 m3 dispensed over 6 h once a week for 2 weeks in each of 7 rooms of a rice mill produced average concentrations of 4.52 to 6.26 µg of dichlorvos/liter of air. This concentration caused higher mortalities among caged test insects than a routine pyrethrins fog: 3-4.5 time. higher among adult cigarette beetles, Lasioderma serricornc (F.); 48-92 times higher among adult red flour beetles, Tribolium castaneum (Herbst); 3-5.5 times higher among adult lesser grain borers, Rhyzopertha dominica (F.); and 5-7 times higher among larvae of the almond moth, Cadra cautella (Walker). The dichlorvos treatments caused a decrease in the insect population of the mill to ¼the pretreatment level. Residues on bagging materials exposed to as many as 1 successive daily treatments (by moving the materials from room to room) were relatively low on cotton (≤531.8 µg/dm2) and paper (≤669.5 µg/dm2), but high on burlap (as much as 3752.4 µg/dm2). Bulk products exposed similarly had residues as follows: 4.48 ppm on rough rice, 1.29 ppm on brown rice, 1.18ppm on milled rice, and 8.26 ppm on bran. Milled rice and bran exposed in burlap bags had only ½ as much residue, milled rice exposed in cotton bags had about the same amount, and milled rice exposed in paper bags had about 1/3 as much residue. Spillage and sweepings exposed to single treatments had residues as follows: 0.67 ppm on rough rice, 0.56 ppm on brown rice, 0.72 ppm on hulls, 1.00 ppm on broken milled rice, and 7.12 ppm on bran.
Document Type: Research Article
Publication date: October 1, 1973
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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.