MALIK MUKHTAR AHMAD AND SHEIKH BILAL AHMAD

The fate of oxydemeton-methyl was studied in 2nd instar grub and adult of Coccinella septempunctata Linn., following topical application. Rate of penetration was almost uniform in both the stages of insect with 90 per cent of applied dose being penetrated within 120 minutes with half life of 36.26 and 32.47 minutes, respectively. There was no difference in the absorption of oxydemeton methyl in the haemolymph at 30 and 60 minutes post treatment in both the stages of the insect, but 46.0 and 43.0 per cent and 53.0 and 50.0 per cent of the applied dose were recovered in the haemolymph of the grub and adult at 90 and 120 minutes post treatment, respectively. Four per cent of oxydemeton methyl could be found from the brain at 60 minutes after treatment in the grub, while as at the same time interval there was no recovery of oxydemeton methyl in the brain of adult. However, no significant difference was found in the accumulation of oxydemeton methyl in the brain of both the stages of insect with only 5.0 per cent of the applied dose being recovered at 90 minutes after treatment; whereas at 120 minutes post treatment slight difference was noticed in the accumulation of oxydemeton methyl in the brain with 3.0 and 4.0 percent of the applied dose being recovered in grub and adult, respectively. The rate of excretion of oxydemeton methyl followed a similar pattern in both grub and adult excreting 3.0, 16.0, 23.0 and 33.0 per cent of the applied dose in grub and 13.0, 20.0, 25.0, and 34.0 per cent of the applied dose in adult respectively at 30, 60, 90 and 120 minutes with half life of 29.53 and 80.52 minutes in case of grub and adult respectively. Both the penetration and excretion rates exhibited first order kinetics