Several strains of Pseudoplusia includens (Walker) (Lepidoptera: Noctuidae) were tested with permethrin, tralomethrin, lambda-cyhalothrin, acephate, and methomyl in laboratory tests. Permethrin was significantly less toxic to strains collected during 1987 (LD50's 3.0 to 4.4 times higher) and 1988 (6.4 to 12.2 times higher) compared with a laboratory strain susceptible to permethrin. In response to methomyl, several field strains also had LD50's that were significantly higher than those determined for the laboratory strain. No significant differences in the toxicity of tralomethrin or lambda-cyhalothrin were observed among strains and only one field strain was significantly less susceptible to acephate than the laboratory strain. In field trials during 1987 and 1988 in Tensas Parish (Paradise and St. Joseph) all treatments, and in Iberville Parish (St. Gabriel), all treatments except acephate (0.84 kg [Al]/ ha) and sulprofos (0.51 kg [Al]/ha) significantly reduced numbers of larvae infesting the plots below numbers present in the untreated control plots. At one location (Tens as Parish, Louisiana), the standard rate of permethrin (0.11 kg [Al]/ha) was not as efficacious during 1987 (75-87% control) and 1988 (61-71% control) as it was during 1982 (97-99% control). None of the other pyrethroids (tralomethrin, cypermethrin, lambda-cyhalothrin, cyfIuthrin), methomyl, thiodicarb, or acephate provided soybean looper control significantly greater than that observed with the permethrin (0.11 kg [AI]/ha) treatment.
Document Type: Research Article
Publication date: February 1, 1990
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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.