Beetle Pheromone Lures Both Sexes

By Rosalie Marion Bliss
August 20, 2002

Agricultural Research Service scientists have discovered a pheromone produced by male Colorado potato beetles--but attractive to both sexes--that may lead to new environmentally sound pest management methods to protect potatoes. The Colorado potato beetle is the potato crop's most destructive pest, costing growers millions of dollars annually in crop losses and expenditures for synthetic pesticides.

The ARS scientists, led by entomologist Joseph C. Dickens with the Chemicals Affecting Insect Behavior Laboratory in Beltsville, Md., reported their discovery in the July issue of the Journal of Experimental Biology.

The Colorado potato beetle rapidly develops resistance to synthetic pesticides, many of which are now being reevaluated by regulators. The pheromone, however, is a natural byproduct of the beetle's metabolism, so the evolution of resistance to it is unlikely. Using the pheromone as a natural chemical for luring and killing the beetles may one day lessen the amount of synthetic insecticides required for pest control.

For 75 years, scientists in the United States, Canada and Europe have searched for scents that attract the Colorado potato beetle. The generally accepted view had been that a pheromone attractant would be found in females. Thus, the discovery of the attractant in males provides a new model for this beetle's chemical communication.

Since 2000, Dickens has identified several scents based on chemicals in potato plants themselves. Those scents were made into the first experimental plant lures to prove effective in field tests.

Under a cooperative research and development agreement with ARS, Trece, Inc., of Salinas, Calif., hopes to create products based on the newly discovered attractants that will exploit the insects' own communication system. New products based on the technology could include attracticides, or bait lures, formulated with small amounts of killing agents.

The scientists now will conduct more tests to determine when and how products using the pheromone-based attractant will transfer successfully from lab to field.

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