Biotech Updates

Effects of Bt Cotton Protein on Biological Parameters of Cotton Aphid

May 2, 2013

Scientists at Universidade Federal da Grande Dourados (UFGD), Brazil, conducted a study to assess the effect of Cry1AC protein expressed in Bt cotton NuPal on cotton aphid (Aphis gossypii), a non-target pest. They also aimed to evaluate the influence of plant age on the development of the aphids.

Bt cotton plants were grown following the technical requirements for planting. The aphids were separated into different containers with a cotton sheet, which was replaced daily with the aid of a cottoncloth. The researchers recorded the biological parameters daily including the duration of each life cycle stages.

Results showed that there were no significant differences in the total duration of instar phases, whether the aphid was exposed to Bt or non-Bt cotton plant. It was only during the reproductive period was differences were observed among genotypes. The number of offspring and longevity total werealso found to be varied at different ages of the Bt treatment. However, the variation in longevity was attributed by the scientists to the type of methodology used in the study and not to the Cry1Ac protein. Thus, they concluded that Bt cotton did not affect the biological parameters of cotton aphid because the results were similar with the aphids reared on conventional cotton.

Read the research article at