1Department of Entomology, Agricultural College, Bapatla - 522101, Andhra Pradesh, India.
2Regional Agricultural Research Station, Lam, Guntur - 522 034, Andhra Pradesh, India.
3College of Food Science and Technology, Bapatla - 522101, Andhra Pradesh, India.
*Part of PhD thesis submitted to Acharya N G Ranga Agricultural University, Rjendranagar, Hyderabad - 500 30, Andhra Pradesh, India.
Survival and development of pink bollworm, Pectinophora gossypiella (Saunders) on 130 and 150 days old bolls of stacked Bt (CryIAc+2Ab), Bt (CryIAc) and normal cottons were examined. The mortality of early larval instars of P.gossypiella was higher than the later instars when fed on 130 days old bolls compared to 150 days old bolls for all the larval instars. Exposure of later instar larvae to plant parts of stacked Bt and Bt cotton cultivars exhibited adverse effects on the growth and development such as reduced larval weight, reduced pupation, formation of small pupae with less weight. The growth and survival indices for P. gossypilla were low on stacked Bt cotton followed by Bt cotton compared to non Bt cotton. Among the stacked Bt and Bt plant parts tested, the growth and survival indices were low on bolls of 130 days old compared to 150 days old.
Development, pink bollworm, Pectinophora gossypiella, stacked Bt cotton, survival
