اثرات حشره‌کش‌ ایمیداکلوپرید بر فراسنجه‌های رشد جمعیت و فعالیت آنزیم‌‌های سم‌زدای شته سبز گندم، Schizaphis graminum Rondani

The wheat green aphid, Schizaphis graminum Rondani (Hemiptera: Aphididae), is one of the most important pests of cereal especially wheatwhich, along with direct damage,cantransfer a number of plants pathogenic viruses. In the present study, the lethal and sublethal effects of Imidacloprid (Imidacloprid Aria®)were evaluated on life history parameters and β-esterase and GST enzymes activity of S. graminumin a growth chamber at 22 ± 2 °C, 60 ± 5 % RH, and16: 8 (L: D) hour photoperiods. Based on the results of the lethality experiments, the pest mortalitywas directly related to the increase in imidacloprid concentration. Lethal Concentrations to kill 30% and 50% of tested insects (LC30 and LC50, respectively) against adult females were 21.46 and 58.56 mg a.i./L. The LC30 of insecticide was used to evaluate sublethal effects.The development time of the peston the insecticide treatment (5.44 days)was longer than the control (6.33 days). The fecundity of pest treated by insecticide (18.36 nymph/adult) was significantly lower than the control(37.91 nymph/adult).The imidacloprid had a significant effect on the total pre-oviposition period (TPOP) of adult female aphids so the longest period was observed in the insecticide treatment (6.25 days).Also, a longer nymphal developmental time was recorded for adult female aphids in the control group.Adult longevity of aphids was significantly lower on the imidacloprid treatment (5.55 days) than on the control (6.10 days).Furthermore, imidacloprid insecticide significantly reduced the population parameters of wheat green aphid.The value of the intrinsic rate of population increase (r) in the control and insecticide treatment were 0.421 and 0.315 day-1, respectively. A significant difference was not observed in the activity of β-esterase and Glutathione-S-Transferaseon the insecticide treatment andcontrol.The results of the present study showed that imidacloprid had hightoxicity to adult female aphids of S. graminum.Also, the LC30 concentration of imidacloprid had a considerable effect on the survival, fertility, reproductive value, and life expectancy of wheat green aphid.Therefore, the insecticide imidacloprid can be suggested as one of the effective agents in the management of S. graminum.