Larviposition Response of Myiopharus doryphorae (Diptera: Tachinidae) to Colorado Potato Beetle (Coleoptera: Chrysomelidae) Larvae Treated with Lethal and Sublethal Doses of Bacillus thuringiensis Berliner subsp. tenebrionis
Larviposition response of Myiopharus doryphorae (Riley) toward Colorado potato beetle, Leptinotarsa decemlineata (Say), host larvae fed for periods of 1 or 24 h on lethal and sublethal doses of Bacillus thuringiensis Berliner subsp. tenebrionis was studied under greenhouse conditions. A significantly shorter delay occurred before the 1st larviposition in hosts fed for 1 h on lethal and sublethal doses of B. thuringiensis compared with the time before larviposition in hosts fed untreated foliage (control). Time before 1st larviposition in hosts fed for 24 h on sublethal doses of B. thuringiensis was also significantly shorter than that for hosts fed lethal doses and control. A substantially lower total number of parasitoid larvae were deposited in hosts fed foliage treated with lethal doses of B. thuringiensis for 24 h than in those fed for 1 h; the lowest rate of parasitization occurred in the hosts fed for 24 h at the lethal dose level. Parasitoid acceptance of sublethally intoxicated Colorado potato beetle larvae and their ability to overcome weaker defensive reactions of these hosts, together with their rejection of lethally infected hosts, indicated that host selection may be based more on manifestations of host vigor and defense than a direct reaction to the presence or absence of B. thuringiensis toxin.
Document Type: Research Article
Publication date: August 1, 1995
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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.