Biotech Updates

Asian Corn Borer Parasite Not Sensitive to Bt Toxin

May 18, 2016

Researchers from the Chinese Academy of Agricultural Science and China Agriculture University investigated the effects of Bt maize with Cry1Ac protein on Macrocentrus cingulum, which parasitizes Asian corn borer.

Results of the indirect bioassay showed that parasitism rate, cocoon weight, and the number of parasitoid progeny produced per host were significantly decreased when M. cingulum-parasitized Cry1Ac-susceptible corn borers were fed with purified Cry1Ac; while life-table parameters of M. cingulum were not significantly affected. These results show that the detrimental effects detected with a Cry1Ac-susceptible host were mediated by poor host quality. On the other hand, direct bioassay showed no difference in life-table parameters when M. cingulum adults were fed with or without Cry1Ac. These findings demonstrate that M. cingulum is not sensitive to Cry1Ac at concentration levels that exceed those encountered in Bt maize fields.

Read the original article in Insect Science.