Toxicities of carbaryl, malathion, parathion, methidathion, and chlorpyrifos were tested against I-d-old first instars of three strains of California red scale, Aonidiella aurantii (Maskell). On the basis of their history, two of these strains were presumed to be susceptible to insecticides. Probit lines for the third strain were slightly to the right of lines for the susceptible strains for malathion, methidathion, and chlorpyrifos, but the shifts were not large enough to suggest resistance. For all strains, chlorpyrifos was most toxic, closely followed by methidathion. Carbaryl was least toxic, and the toxicities of parathion and malathion were intermediate between those of carbaryl and methidathion. Use of different spreader-stickers with the insecticides affected the concentration-mortality responses of California red scale to some insecticides. Therefore, for comparative work, we suggest that a single spreader-sticker should be used. Diagnostic concentrations for testing populations of California red scale for resistance to each of these insecticides are recommended.
Document Type: Research Article
Publication date: February 1, 1991
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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.