The Effectiveness of fenitrothion (EC50%) on the Increase of Bioenergetic Resources in Sunn Pest, Eurygaster integriceps Put

Sunn pest, Eurygaster integriceps, is one of the key pests of wheat that overwinters as adult. The amount of stored bioenergetic components are important in the survival of adults during the winter. In this research, the effects of sublethal concentrations (≤ LC30) of fenitrothion (Sumithion® 50% EC) were studied onbioenergetic resources in new generation of adults under field conditions. The experiments were designed as factorial with four factors; fenitrothion concentrations (0, 1, 3 and 5 μl/l), sex (male and female), sampling time (3 and 6 days after treatment) and number of treatments (first and second) and were replicated four times in a randomized complete design experiment. Lipid, carbohydrate and protein levels were determinedin mg/g, w/w and wet weight, respectively. The results revealed that fenitrothion affected the bioenergetic resources significantly. Lipid, glycogen and protein levels were increased in the treated individuals comparedwith the controls (1.96, 4.25, and 2.4 times, respectively) and sugar levels declined 2 times in the treated individuals. The mean of caloric contents in 0, 1, 3 and 5 μl/l concentrations of fenitrothion were 0.755, 1.291, 1.085 and 1.764 cal/mg, respectively. Glycogen content decreased nearly 90% after the second treatment in respect of the first one, but lipid levels increased 2 times. Therefore, the application of sublethal concentrations (≤ LC30) of fenitrothion can increase some bioenergetic resources in adult Sunn pest and may help it to pass the winter safer.