Host associated variations in esterase and glutathione-s-transferase in Bemisia Tabaci

In the present study, the populations of Bemisia tabaci were collected from five locations on cotton and subsequently reared and established on brinjal and tomato to study host associated variations in esterases and glutathione-s-transferase. Pyrethroids, carbamates and organophosphates were the most widely used group of insecticides in these locations. Frequent failure of these have been continuously reported that may be attributed to enhanced levels of detoxifying enzymes due to continuous selection pressure. Significant variation in both the enzymes levels was found across the population and host. Khandwa population recorded the maximum esterase activity with 2.21 fold (4.33± 0.48 mOD/min/0.5 B. tabaci equivalent), 1.67 fold (4.83± 0.39mOD/min/0.5 B. tabaci equivalent) and 1.69 fold (5.34± 0.38 mOD/min/0.5 B. tabaci equivalent) for brinjal, cotton and tomato, respectively. Population from Khandwa and Sriganganagar recorded the maximum activity of glutathione-s-transferase with 1.71 folds (243.77± 6.56nmol/min/B. tabaci equivalent, 243.88± 25.66nmol/min/B. tabaci equivalent) for both populations on brinjal; 1.75 (263.53± 17.53nmol/min/B. tabaci equivalent) and 1.76 (265.74± 18.04nmol/min/B. tabaci equivalent) folds on cotton; 1.72 (289.28± 9.82nmol/min/B. tabaci equivalent) and 1.66 (279.40± 23.21nmol/min/B. tabaci equivalent) folds on tomato, respectively, taking New Delhi population as unity. Tomato recorded the maximum value for both the enzymes followed by cotton and brinjal as host.