A glass vial bioassay was used to determine the toxicity of 10 insecticides to 3 strains of the boll weevil, Anthonomus grandis grandis Boheman, ectoparasitoid Catolaccus grandis (Burks). Technical-grade samples of dimethoate, endosulfan, oxamyl, acephate, malathion, azinphos-methyl, cyfluthrin, methyl parathion, spinosad, and fipronil were used in bioassays. Three strains of C. grandis were tested: 2 in vivo-reared strains, (i.e., the In Vivo strain and the Sinaloa strain), and 1 in vitro-reared strain reared on an artificial diet completely devoid of insect components (i.e., the In Vitro strain). Endosulfan, spinosad, and azinphos-methyl were significantly less toxic to the In Vivo strain than other treatments. Endosulfan was also significantly less toxic to the Sinaloa strain than other treatments. Azinphos-methyl was significantly less toxic to the In Vitro strain than other treatments. In addition, malathion, the insecticide most widely used in boll weevil eradication, was significantly more toxic to the In Vitro strain than other treatments. However, it cannot be determined directly from the data which insecticides may be more toxic to C. grandis in the field. Bioassays must be refined so that risks to natural enemies can be predicted reliably. In so doing, chemical insecticides may be developed and used that may be selective (i.e., more toxic to a pest than to a beneficial species). The data reported herein, however, is likely to be useful to many ecotoxicologists.
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.