New Trap for Troublesome
By Dennis Senft
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 USDAs 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 Californias Imperial Valley, Chu said.
Growers may use traps to monitor the whiteflys 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,
The new traps could have a use indoors--in greenhouses. Its
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 traps 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 Laboratory
in 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