الفهرس | Only 14 pages are availabe for public view |
Abstract Systemic insecticides are effective against a variety of sap-sucking pests, especially aphids. In vivo experiments, the toxicity of thiamethoxam (THIA), sulfoxaflor (SFX) and spinosad (Sp) was assessed by using the leaf dipping method, against a laboratory strain of cowpea aphid (Aphis craccivora Koch.). At 48 hrs post-treatment, THIA, SFX, and SP demonstrated good toxicity against adult aphids with LC50 values of 0.75, 0.29, and 6.85 ppm, respectively. In silico analysis, THIA, SFX, and SP were docked to the acetylcholine binding protein (AChBP) to demonstrate the variation in their binding interaction. Aphids treated with LC50 of THIA showed elevations in activities of antioxidant enzymes, peroxidases, and acetylcholinesterase, while alpha esterase, carboxylesterase (CarE), glutathione S-transferase, and catalase activities were decreased. On the contrary, SFX and SP treatment greatly reduced all enzymes activities except peroxidase, which increased following treatment. Overall, these compounds have low mammalian toxicity and excellent, selective, and irreversible binding with the nAChR, making them effective against sap-sucking pests. |