author(s)
Zunnu Raen Akhtar, Zain Saeed, Aqsa Noreen, Anjum Jabeen, Hasooba Hira, Arbab Ihsan and Easha

abstract
An experiment to detect the resistance development in pink boll worm against Bt cotton was conducted under laboratory and field condition. In laboratory pink boll worms were reared and whole life cycle was observed on Bt cotton as compared to control variety. While ELISA was conducted to observe the Bt protein presence in pink boll worms larvae. In field studies, population dynamics were observed in Bt cotton as compared to control to know, if Bt cotton expressing Cry 1Ac can control or reduce pink boll worm population. Results showed that life cycle parameters of pink boll worms on Bt cotton were similar to non-Bt cotton. In both of varieties, there was no significant difference in any life parameter when larvae were fed on Bt cotton as compared to control. ELISA results showed that Bt protein was present in pink boll worm in trace amounts. While Bt protein was present in higher concentration in bolls when collected from the fields. Field studies revealed that there was no significant difference in pink boll worm population dynamics in both varieties as compared to control. Laboratory results were in conjugation to field studies. These results show that the pink boll worm has developed the resistance against Bt cotton, so more research is required to observe the Bt protein role in pink boll worm.