Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore - 641 003, India.
The persistent toxicity of commercial formulations of imidacloprid 17.8 SL, thiamethoxam 25 WG and methyl demeton 25 EC was estimated against Aphis gossypii and Amrasca biguttuala on bhendi crop. The insecticidal treatments differed considerably in their persistence, period of efficacy and index of persistent toxicity (PT value) against both the insects. Of different treatments, the higher dose of imidacloprid showed longest persistence up to 27 days for aphids and 29 days for leaf hoppers. This was followed by recommended dose of imidacloprid and thiamethoxam irrespective of the insect species. The conventional insecticide. methyl demeton showed shorter persistence for a period of 13 and 17 days against aphids and leafhOppers, respectively.
Aphids, bhendi, imidacloprid, leafhoppers, toxicity
