Dosage-Mortality Studies with Pyrethroids and Other Insecticides on the Tobacco Budworm (Lepidoptera: Noctuidae) from the Imperial Valley, California

Publisher Website
Google Scholar
Abstract
Dosage-mortality studies were conducted on populations of the tobacco budworm, Heliothis virescens (F.), from the Imperial Valley of California in 1979, 1980, and 1981. Progeny of field-collected budworms showed a steady increase in resistance over this period. Levels of resistance to permeethrin, fenvalerate, and methyl parathion increased to 51-, 29-, and 18-fold, respectively, compared with data from a susceptible laboratory colony. The LD50 for methomyl was greater than 2,000 µg/g of body weight, whereas the LD50 for this compound in the susceptible strain was 3.25 µg/g. Values obtained in the first generation decreased in the second generation of laboratory rearing and remained at this lower level in subsequent generations. This indicates that evaluation of insecticide resistance in this insect should be performed on the first generation. Response to permethrin was not different using field-collected larvae or adults to initiate the colony. However, higher LD50 values were obtained during October as compared with September collections.

This publication has 0 references indexed in Scilit: