Toxicity of N'-nitrohydrazinecarboximidamides to several aphids and the influence on the activities of related enzymes in Aphis gossypii

Su50 (N'-nitro-1-isopropyl-2-(4-nitrobenzenemethene) aminoguanidine) and Su56 (N'-nitro-1-allyl-2-n-propyl-aminoguanidine) were compounds with the feature of neonicotinoid and semicarbazone that were synthesized by splicing the active substructure. In order to determine the insecticidal activity and mechanism against aphid, Aphis gossypii Glover, Myzus persicae, Aphis citricola and Hyalopterus amygdali were chosen as the target and leaf-dip method was used. The influence of Su56 on carboxylesterase (CarE), acetylcholinesterase (AChE), glutathione S-transferase (GSTs) and multifunction oxidase (MFO) was investigated at sub lethal concentration (LC10 and LC25). The results showed that Su50 and Su56 had insecticidal activity against the 4 kinds of aphids, howerve, the difference was not significant. For A. gossypii, M. Persicae, H. amygdale and A. ciricola, the LC50 values of Su50 were 13.0, 24.2, 62.6 and 14.3 mg/L and the LC50 values of Su56 were 30.3, 30.2, 101 and 3.23 mg/L, respectively. The two compounds also showed antifeedant activities against A. gossypii. The LC10 and LC25 of Su56 had no significant effects on CarE, GSTs and MFO activities of A. gossypii. However, AChE was inhibited significantly treated by LC10 of Su56.