Authors : H.A. Shahout, J.X. Xu, J. Qiao, X.M. Yao and Q.D. Jia
Abstract: Methoxyfenozide is an ecdysone agonists, belonging to a novel group of Insect Growth Regulators (IGRs). In this study, the sublethal effects of methoxyfenozide on growth and development of common cutworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) were evaluated. The (2nd and 5th) instars larvae of S. litura were fed on cabbage leaves, treated with sublethal concentration of methoxyfenozide (LC10, LC30) (which were estimated based on the laboratory preliminary experiments bioassay. After 48 h of the feeding on cabbage leaves treated with methoxyfenozide, larvae were moved and fed on cabbage leaves free of chemicals and allowed to them to grow and pupate until the adult emergence. The results revealed that when larvae 2nd instar were treated with methoxyfenozide the 3rd-6th larval instar duration was significantly (p<0.05) increased by both (LC10, LC30 ) of methoxyfenozide. Also pupation percent, pupal weight, adult emergence and adult longevity were significantly (p<0.05) reduced by both (LC10, LC30) of methoxyfenozide when both (2nd and 5th) instar larvae were treated. However, the pupal duration was significantly (p<0.05) prolonged when both (2nd and 5th) instar larvae were treated with (LC10, LC30) of methoxyfenozide compared to the control. The results also revealed that when S. litura larvae (2nd and 5th ) instars 2nd and 5th were treated with sublethal doeses (LC10, LC30) of methoxyfenozide the adult duration (longevity) was significantly (p<0.05) reduced however, the reduction was more pronounced when the LC30 of methoxyfenozide was applied to larvae 5th instars. Researchers concluded that the sublethal effects of methoxyfenozide might exhibit significant (p<0.05) effects on the population dynamics of S. litura as well as it might play a vital role 2nd and 5th in Integrated Pest Management program (IPM).
H.A. Shahout, J.X. Xu, J. Qiao, X.M. Yao and Q.D. Jia, 2011. Sublethal Effects of Methoxyfenozide on Growth and Development of Common Cutworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). Research Journal of Biological Sciences, 6: 58-64.