14 May 1999

Corn borers beat new tech

LABORATORY tests on corn borer insects have shown that they can rapidly adapt and overcome the genetically modified maize plants designed to kill them.

Research carried out at Kansas State University in the US, concludes that corn borers, one of the main pests responsible for damaging maize crops, could rapidly develop resistance to Bt maize which is modified to produce specific toxins to kill the insect.But the researchers found that some insects were immune to the toxins and resistant populations of corn borers developed quickly because they produce many generations of offspring each year.

The report warns: "There is essentially no escape from widespread resistance in the European corn borer and resistance on a local scale is likely to evolve.

"And the development of Bt resistance has already been recorded in the Indian meal moth," it says.

The report warns that maintaining the effectiveness of Bt maize after it reaches the marketplace will be the responsibility of seed companies, educators and farmers.

"Education about the limitations of this new technology and the potential development of insect resistance must be communicated to farmers along with management recommendations on how to limit resistance," it concludes. &#42