IN VITRO ASSESSMENT OF SOME IPM COMPONENTS AGAINST MAJOR SUCKING PESTS OF COTTON

The present study deals with the predatory response of ladybird beetles and estimate the parameters of the type of response showed by it. Toxicological studies of imidacloprid and acephate was done to know the median lethal concentration/dose and also monitor the resistance to these insecticides in leafhoppers collected from different localities. Ladybird beetle C sexmaculata shows a type II functional response to increasing densities of prey i.e., Aphis gossypii at cumulative exposure of 12 and 24 hrs to it’s prey. The attack rate or searching efficiency was found to be higher at 12 hrs (0.0391/12 hrs) than at 24 hrs (0.0254/24 hrs) of exposure as against it at 12 hrs handling time was found to be shorter (0.3654 hrs or 21.92 min) than 24 hrs(0.4441 hrs or 26.65 min). Imidacloprid was the more toxic insecticide to the leafhopper with lowest LC50 value in all locations, Kanshivni (175.51 ppm), Chandur (95.92 ppm) and susceptible (21.68 ppm) as compared to acephate with LC50 values at Kanshivni (607.76 ppm), Chandur (483.37 ppm) and susceptible (51.11 ppm) Relative Toxicity of imidacloprid was higher as compared to acephate at all locations. Imidacloprid was 5.04, 3.46 and 2.36 times more toxic than acephate at Chandur, Kanshivni and in field susceptible population. Leafhopper developed 11.89 fold resistance to acephate at Kanshivni village, district Akola.