New Lure Works Better Than Pheromones for Codling
By Kathryn Barry
June 20, 2001
Apple, pear and walnut growers will soon have a new tool to control
codling moths, thanks to Agricultural
Research Service scientists and a commercial company.
ARS entomologist Douglas M. Light discovered that one of the chemicals
responsible for a pears sweet odor, known as the pear ester, attracts
both female and male codling moths. Light works at the
Research Unit of ARS Western
Regional Research Center in Albany, Calif.
Codling moths are the most severe and widely distributed pest of apples,
pears and walnuts in the world. Uncontrolled, the larvae--the "worm in the
apple"--can destroy up to 95 percent of an apple crop and up to 60 percent of a
pear crop. In walnuts, the larvae damage the nuts and create holes in the hull
and shell that can allow fungi to enter.
Pheromones, sex hormones produced by the females, are widely used in
monitoring and mating disruption programs, but only attract male moths.
Researchers estimate that 90 to 95 percent of male codling moths in an orchard
must be trapped or prevented from finding a mate to reduce the number of
fertile eggs laid by females to an economically manageable level. Capturing
female moths has an even greater potential to reduce offspring without
widespread spraying of chemicals.
Through a cooperative research and development agreement,
Trécé, Inc., of Salinas,
Calif., is developing commercial monitoring tools using the pear ester.
Trécé also plans to include the attractant in a sprayable lure
formulation known as an attracticide, which contains small amounts
ARS and Trécé share a patent on this technology and
additional patents are pending.
A story on this
research appears in the June issue of Agricultural Research, the
agencys monthly magazine.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.