Read: about the research in Agricultural Research.

Controlling Corn Rootworms With Less Insecticide

Corn rootworms may develop insecticide resistance more slowly now with new technology that's designed to avoid using the same insecticides year after year and to control adult beetles instead of larvae.

Agricultural Research Service scientists, working with industry, have found ways to attract the beetles to any of at least three types of insecticides strategically sprayed on plant leaves at about 1/10th the rate normally buried into soil.

The idea began as scientists at the ARS National Center for Agricultural Utilization Research and the Biotechnology Research and Development Corp., Peoria, Ill., were solving dual problems with spray-applied biological control agents. If rain didn't wash away caterpillar-killing viruses and bacteria soon after they were sprayed on leaves where insects would feed, the harsh sun would likely deal the microbes a quick untimely death. The remedy, on both counts, turned out to be a new spray formulation including the sticky protein wheat gluten made soluble by a chemical such as citric acid. Spray droplets, as they dried, adhered like glue and the gluten shielded the microbes from ultraviolet rays. A patent was issued in 1996.

In a Cooperative Research and Development Agreement (CRADA) between ARS and Trécé Inc., again wheat-gluten-based formulations proved useful. In 1999 the company licensed the invention and now markets the formulations under the name CIDETRAK. When combined with any of at least three types of insecticides--pyrethroids, carbamates and organophosphates--at 1/10th normal application rates, CIDETRAK has worked better than conventional sprays. The partners have extended the CRADA into 2001 as they test the potential of other insecticides.

An article about the research appears in the November issue of ARS' Agricultural Research magazine.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.

Scientific contact: Robert W. Behle, ARS National Center for Agricultural Utilization Research, Peoria, Ill., phone (309) 681-6225, fax (309) 681-6693, behlerw@mail.ncaur.usda.gov.