The field study was conducted to evaluate the Bt cotton hybrids against mirid bug, Creontiades biseratense Distant (Hemiptera:Miridae) at Cotton field of Perambalur district during 2015-2016 and 2016-2017 with 17 BG II Bt hybrids and 2 varieties. The data revealed that Ankur Jai BG II Bt and VICH 303 BG II Bt hybrids recorded lowest mirid bug population (8.68 bugs/plant, 9.09 bugs/plant), lowest per cent square damage (10.18& 12.73), poor per cent parrot beak bolls (2.27& 3.5) and highest seed cotton yield (1773.2 kg/ha & 1788 kg/ha)among the tested hybrids during 2015-2016. Whereas Ankur Jai BG II Bt alone recorded lowest mirid bug population (7.84 bugs/plant), lowest per cent square damage (7.83) and lowest per cent parrot beak bolls (2.69) during 2016-2017. But VICH 303 BG II Bt hybrid recorded highest seed cotton yield (1786 kg/ha) than Ankur Jai BG II Bt (1752 Kg/ha) during 2016-2017.This study concluded that, none of the Bt hybrids were not resistant to mirid bugs but Ankur Jai & VICH 303 BG II Bt hybrids recorded lowest mirid bug population, poor fruiting bodies damage and highest yield. Use of these two genotypes should be an important component while formulating the IPM strategies for the management of mirid bug, C.biseratense in Bt cotton.
