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Wasp That Attacks Western Plant Bug May Control Its Mid-Atlantic CousinBy Hank Becker
March 8, 2000
A new species of parasitic wasp discovered in Idaho attacking the western tarnished plant bug may help control a related pest species in the mid-Atlantic states.
Much of the seed needed to grow many important domestic crops is produced in the northwestern United States. Each year, the western tarnished plant bug (WTPB), Lygus hesperus, and its cousins suck the sap from flowers, young fruits and seeds. To prevent serious reductions in quantity and quality of the seed crops, growers spend tens of millions to control this major pest.
An ARS researcher at the Beneficial Insects Introduction Research Laboratory, Newark, Delaware, cooperating with a University of Idaho-Parma Moscow scientist, discovered a previously unknown species of parasitic wasp attacking the WTPB in alfalfa seed fields in southwestern Idaho.
Over three WTPB generations in 1997 and 1998, the wasp killed 44 to 81 percent of the pests. Further research in Idaho is warranted to determine if this degree of parasitism is sufficient to reduce the need for insecticides.
After a retired ARS taxonomist verified the ARS entomologist's determination that the Idaho parasite was a new wasp species, a cooperating University of Wyoming-Laramie scientist described it as Peristenus howardi Shaw. P. howardi was later discovered in eastern Washington state and may also be in Oregon.
In ARS laboratory tests, the new wasp readily parasitized the tarnished plant bug (TPB), Lygus lineolaris--a close relative of the WTPB. The TPB is an important pest of many crops in the eastern half of the United States but has no significant natural enemies south of New York.
A European parasite, Peristenus digoneutis Loan, established by the ARS Newark lab, is a promising biological control agent in New England, New York, northern Pennsylvania and New Jersey.
P. howardi was recently released under permit in Delaware, with the goal of permanently establishing it to reduce TPB damage to fruits and vegetables in the mid-Atlantic states.
ARS is the chief research agency of the U.S. Department of Agriculture.
Scientific contact: William H. Day, ARS Beneficial Insects Introduction Research Laboratory, Newark, Del.; phone (302) 731-7330, ext. 24, fax (302) &37-6780, firstname.lastname@example.org.