Department of Entomology, Acharya N.G. Ranga Agricultural University, Agricultural College, Bapatla - 522 101, Andhra Pradesh, India.
*Corresponding author's: E-mail: raoento@yahoo.co.in, Fax No: 08819 247583, Cell: 9848 646780
1A part of approved Ph.D thesis submitted by N. Srinivasa Rao to Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad.
The third instar larvae of H. armigera exhibited restless behaviour with minimum feeding and no orientation on Bt cotton hybrids. None of the 1st and 2nd instar larvae of H. armigera survived to adults when fed with Bt cotton flower buds. However, few 3rd (<10%) and many 4th (>35%) and 5th (>42.5%) instar larvae successfully transformed into adults. In addition, post-ingestive food utilization efficiencies were also low on Bt cotton flower buds and they were negatively correlated with the concentration of the toxic ‘Cry’ protein present.
