Four species of lepidopterous larvae were treated by topical application with several insecticides. LD-50 values were established on a g. insecticide per gram of larval weight basis for a number of different weight groups for each species. The southern armyworm, Prodenia eridania (Cram.), gave a nearly constant LD-50 value for the different weight groups using DDT or Phosdrin® (1-methoxycarbonyl-1-propen-2-yl dimethyl phosphate, 60% technical) as the insecticide, as did the tobacco hornworm, Protoparce sexta (Johan.), with endrin. The corn earworm, Heliothis zea (Boddie), gave no increase in the LD-50 for Phosdrin but gave more than 1,000-fold increase with DDT from larvae weighing 0.1 gm. to those weighing 0.5 gm. Of the eight insecticides tested on the tobacco budworm, Heliothis virescens (F.), only Phosdrin remained constant for the different size groups. Guthion® (O,O-dimethyl S-(4-oxo-3II-l,2,3-benzotriazine-3-methyl) phosphorodithioate), Dipterex® (0,0-dimethyl 2,2,2-tr ichloro-1-hy droxyethy lphosphonate), and malathion gave increases of 2 to 10 times, while endrin, DDT, toxaphene and TDE give increases of from 20 to 100 times.
Document Type: Research Article
Publication date: December 1, 1959
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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.