
Along Came A Spider...and "Sat Down" Some Crop PestsBy Hank Becker August
3, 1998Few tiny creatures are as hugely feared as spiders. But scientists at the
Agricultural Research Service believe
native spiders deserve more respect--instead of neglect--as natural pest
controls. The scientists' new biochemical tests can tell what the spider--or
other tiny predator--ate for lunch. They used one of the tests to discover that winter spiders (Chiracanthium
innclusum) may be helping cotton growers. It revealed that eggs of two
cotton pests had been on the menus of about one-fourth of the winter spiders
collected in a Georgia cotton field. ARS entomologist Matthew
H. Greenstone in Stillwater, Okla., other ARS researchers and their
colleagues have been pioneering the new tests, which follow an approach called
serological analysis. This means using monoclonal antibodies--custom-designed
molecules--to identify a prey's remains in a predator's gut. The researchers
say this is the most direct way to gather long-term data on predation. One of the new tests can distinguish the cotton bollworm from its
cotton-infesting cousin, the tobacco budworm, in the guts of spiders. In Colorado, the scientists conducted the first North American survey for
spiders that kill cereal aphids and other wheat pests. Then they began devising
monoclonals to learn which spiders--and other predators--eat greenbugs, Russian
wheat aphids and corn leaf aphids. All three are major pests of cereal crops. The scientists are also collaborating on other monoclonals that will help in
gauging how well predators suppress cereal aphids around the world. A story about the new tests appears in the August issue of Agricultural
Research magazine. The story is also on the World Wide Web at: http://www.ars.usda.gov/is/AR/archive/aug98/spid0898.htm Scientific contact: Matthew H. Greenstone, ARS
Plant Sciences and
Water Conservation Research Laboratory, Stillwater, Okla., phone (405) 624-
4119, fax (405) 372-1398, [email protected]. U.S. Department of Agriculture | |