
Corn Rootworms Will Die for WatermelonBy Judy McBride May
21, 1998The juice from a bitter watermelon would gag most people. But it tastes
like a hot fudge sundae to corn rootworms. Agricultural Research Servicescientists identified the ingredient in the juice that causes the insect to
gorge. They developed a process for extracting the active ingredient along with
the juice and combined the solution with a red dye that's deadly to rootworms
but safe for people and animals. In preliminary field tests last summer, the watermelon-dye combo took a
promising bite out of the costliest insect pest in the U.S. Three days after
application, it had killed 85 percent of adult rootworms compared with 65 and 70
percent for two other controls--both pesticide-bait combinations. Corn rootworms cost U.S. farmers $1 billion annually in lost crops and
control measures. Farmers apply pesticides on 30 to 40 million acres--often as
a preventative measure--to keep these little gluttons from leaving their crops
without a root to stand on. Researchers at the Beltsville, Md., Agricultural
Research Center wanted a control that would spare the environment and foil
the rootworms from developing insecticide resistance. ARS entomologist Robert
Schroder and colleagues have applied for a patent on their formulation. The
watermelon-dye combo zeros in on the adult stage of the insect. This breaks the
reproductive cycle so next year's population is lower. The lethal agent is the same D & C Red Dye No. 28 approved by the
Food and Drug Administration for use in drugs
and cosmetics. It is now in the registration process, in combination with a
different kind of bait, for controlling fruit flies. ARS studies with the dye have been conducted under cooperative research and
development agreements with PhotoDye
International Inc., of Baltimore, Md. A story about the research appears
in the May issue of Agricultural Research magazine. The story is also
on the World Wide Web at: http://www.ars.usda.gov/is/AR/archive/may98/root0598.htm Scientific contact: Robert F. W. Schroder, ARS Insect Biocontrol
Laboratory, Beltsville, MD 20705-2350; phone (301) 504-8369, fax (301) 504-8190,
[email protected]. U.S. Department of Agriculture | |