EVOLUTION OF PESTS TOO QUICK FOR TOXINS.

Byline: Laura Beil Dallas Morning News

Crop pests may become resistant to some insecticides with surprising ease, a new study suggests.

Pesticide manufacturers like to use toxins from a common soil bacterium in their products because the chemicals kill bugs but don't appear to harm people. New research examining diamondback moths, however, has found that just one gene, like a key that opens several doors, can give the insects resistance to at least four different toxins.

Prior to these results, most agricultural experts assumed that to develop resistance, bugs would need a separate genetic mutation for each different chemical.

``These findings suggest that pests may evolve resistance to some groups of toxins much faster than previously reported,'' the researchers report in the current issue of Proceedings of the National Academy of Sciences.

The experiments were conducted by scientists from the University of Hawaii, the Biotechnology Research Institute in Montreal and Clemson University.

The researchers also found that 21 percent of the moths examined already carried one copy of the gene. A bug would need two copies, one from each parent, to become pesticide-resistant.