Effects of Cyfluthrin Insecticide on Agrotis ipsilon Immature Stages Development with Respect to Different Temperatures

Abstract

Toxicity effects of Cyfluthrin insecticide on Agrotis ipsilon (Lepidoptera: Noctuidae) immature stages were studied with respect to temperature thresholds and thermal requirements for each stage. The bioassays were carried out by applying the recommended concentration, its half and its quarter at four constant temperatures (15, 20, 25 and 30°C). The LC-values of Cyfluthrin were estimated, and the LC25 values were applied for each tested temperature as sub-lethal concentration. Results revealed that, the LC50 values at 30°C were highly toxic to all treated individuals than other tested temperatures, followed by that at 20°C then at 25°C, while the least LC50 value was recorded at 15°C. The mean estimated thermal units and Zero of development were 37.66, 106.39, 31.88, 151.70 & 238.33 degree days (DD), and 13.30, 12.53, 8.30, 8.04 and 11.37°C for eggs, larvae, prepupae, pupae and total immature stage, respectively. The developmental period of the examined stages was decreased with increasing temperature.