New Trap for Troublesome Insect

Phoenix, Ariz., Feb. 6--Farmers may get help fending off silverleaf whiteflies from a new, inexpensive trap invented by U.S. Department of Agriculture scientists to catch these billion-dollar pests of cotton, vegetables and other crops.

The trap is basically an inverted 12-ounce clear plastic drinking cup suspended over a bright yellow base, said one of the inventors, plant physiologist Chang-Chi Chu with USDA’s Agricultural Research Service. ARS is seeking a patent on the new trap, Chu said.

The silverleaf whitefly, also known as strain B of the sweetpotato whitefly, is a pest of more than 300 plants worldwide. Crops in Arizona, California, Texas and Florida have been especially hard hit by the tiny, sap-sucking insect since its discovery in this country in 1986. From 1991 to 1994, for example, the whiteflies have been blamed for close to $1 billion in farm and related economic losses in southern California’s Imperial Valley, Chu said.

Growers may use traps to monitor the whitefly’s population buildup in crop fields. The number trapped lets a grower determine the most effective and economical timing for control practices such as releasing predatory insects or spraying insecticide, Chu said.

Unlike currently used yellow sticky traps, the new one attracts only adult whiteflies and no other insects. Chu said this allows faster estimates of their population densities. The new traps also are not messy and are easier to handle, re-usable, cheaper and take less time and labor to count and maintain, he added.

The new traps could have a use indoors--in greenhouses. “It’s possible that hanging a number of the traps in a greenhouse might eliminate the need for insecticides where wasp parasites are released to control whitefly larvae,” Chu said. ARS scientists tested the new traps at sites in California and Arizona.

“The new trap takes advantage of three behavioral traits of whiteflies--they find yellow irresistible, they crawl toward shade when they land on leaves, and they fly toward light when leaving,” Chu said.

“With mass production, costs should be low,” said Thomas J. Henneberry, another of the trap’s co-inventors. “I envision a plastics manufacturer could get the traps on the market for about a dollar apiece.” Henneberry is director of ARS’ Western Cotton Research Laboratoryin Phoenix, Ariz.

Scientific contact: Chang-Chi Chu or Thomas J. Henneberry, Western Cotton Research Laboratory, Agricultural Research Service, USDA, Phoenix, Ariz. 85040-8807. Telephone: (602) 379-3524, extension 236; fax: (602) 379-4509