Scientists Investigate Long-term Effects of Bt Cotton on Aphids

Scientist Ju-Hong Zhang from Jilin University, China, and colleagues conducted a study to investigate if Bt cotton affects aphids (Aphis gossypii), a non-target organism. The team compared the life-table parameters of aphids for the first to 37^th generations that fed on Bt cotton to those that fed on non-Bt cotton cultivars. To detect the transmission of Bt protein from Bt cotton to aphids' honeydew, the team used enzyme-linked immunosorbent assay (ELISA) method.

Results showed that the life-table parameters of the Bt cotton-fed aphids did not differ significantly from those that fed on non-Bt cotton from 1^st to 37^th generations. Based on the assay, Bt protein is present in the Bt cotton leaves, and the content varied at different growth stages. Traces of Bt protein were found in the Bt-fed aphids as well as in their honeydew.

The authors of the study concluded that even if there are traces of Bt protein found in the aphids, the protein still had no negative impact on aphids in short or long term.

Read the research article at http://www.academicjournals.org/ajb/PDF/pdf2012/22May/Zhang%20et%.20al.pdf.