Comparison of antibiosis of spotted bollworm,Earias vittella (Fab.),on two Bt- and one non Bt- cotton varieties

In order to determine antibiosis of spotted bollworm (sbw),earias vittella (fab.) (arctiidae: lepidoptera) on two bt (fh 113 and fh 114) and one non bt (fh 2015) varieties,infestation,life cycle and enzymes activity of the bollworm were compared on these varieties. results revealed that the seasonal infestation of squares was the highest (9.5%) on fh 2015 followed by fh 113 (6.2%) and fh 114 (4.9%). fh 2015 (3.2-17%) had statistically high flower infestation than fh 113 (1.5-1.9%) and fh 114 (0.6-2.0%). the seasonal percent infestation of bolls was significantly highest (6.8%) on fh 2015 than fh 113 (2.1%) and fh 114 (2.4%). the biology of sbw on these varieties showed that egg incubation and larval durations were longer on bt varieties as compared to non bt variety. the activities of non specific esterases were high in larvae reared on bt varieties whereas total proteases were low on these varieties. the physiological adaptation of sbw on bt cotton varieties is discussed. copyright 2012 zoological society of pakistan.