WERA066: Integrated Management of Russian Wheat Aphid and Other Cereal Arthropod Pests.
Statement of Issues and JustificationInsect pests including Russian wheat aphid, Diuraphis noxia, greenbug, Schizaphis graminum, and Hessian fly, Mayetiola destructor, are serious pests of cereal crops in the U.S. Since its introduction into Texas in 1986, Russian wheat aphid has spread throughout the western Great Plains cereal production area, the Pacific Northwest, and the desert Southwest. The total economic damage in the U.S. caused by Russian wheat aphid has exceeded $1 billion since 1986, considering crop loss, cost of pest control, and lost revenue to rural economies. Russian wheat aphid is a chronic annual pest of cereals in eastern Colorado and surrounding wheat producing areas. It also causes localized periodic damage throughout the rest of its distribution range of the western continental U.S. In 2003, a new biotype of the Russian wheat aphid was detected (designated RWA2) which had overcome Dn4 resistance that had been incorporated into several wheat varieties and deployed in the SW Great Plains region. Soon, more biotypes were detected which now number from RWA1 to RWA8. The development of these new biotypes has become a serious threat to the deployment of resistant varieties which are the primary management tool for this aphid. Crop losses from aphid pests are most common on stressed plants grown in marginal soils. Damage from Russian wheat aphid is most common in low rainfall, dryland cereal production areas, where growers tend to have the narrowest profit margins.
The greenbug is a worldwide pest of wheat and other small grains. It was first reported as a pest in North America about 125 years ago. Damage from greenbug occurs throughout the Western Region, but is most severe when rainfall is low. Annual losses attributed to greenbug average $12 million per year in the central and western Great Plains and parts of the inter-mountain basin, but can increase to over $100 million per state during severe outbreaks.
Hessian fly has been a perennial pest of wheat since it was first found on Long Island, NY in 1779. While it has been largely a pest in the eastern soft winter wheat region, it has become more problematic in western states. In 1978 it was found on the Texas-Oklahoma border and moved south. During 1984, Hessian fly caused an estimated loss of $5 million in Texas alone. Hessian fly has also been problematic in Kansas, with yield losses of 6-30% (per field) during 1993. In Georgia, Hessian fly infestation on wheat resulted in about $28 million losses during the 1988-89 cropping year. A recent upsurge in Hessian fly activity has been noticed in Oklahoma, Kansas, and Nebraska that appears to be related to the increase of no-till wheat acreage.
Several other arthropods can also seriously impact wheat, barley and oat production in the western U.S. These include the chinch bug, Blissus leucopterus leucopterus, wheat stem sawfly, Cephus cinctus, brown wheat mite, Petrobia latens, wheat curl mite, Aceria tosichella, winter grain mite, Penthaleus major, cereal leaf beetle, Oulema melanopus, as well as various cutworms (Lepidoptera: Noctuidae) and other aphids such as the bird cherry-oat aphid, Rhopalosiphum padi, rice root aphid, R. rufiabdominalis, and English grain aphid, Sitobion avenae.
Promoting and sharing research necessary to help manage cereal aphids and other arthropod pests in the Western Region is a primary goal of WERA-066. Continuation of the interdisciplinary approach taken by members of WERA-066 will provide the principal mechanism to further stimulate interaction and coordination among workers to address comprehensive management of the Russian wheat aphid and other cereal arthropods in small grain cropping systems. By providing an annual forum for discussion and sharing of data on arthropod pests of cereal grains, WERA-066 will shorten the time from initial research activity to adoption by the end user. Collaboration among researchers from different states and organizations will synergize research and sharing of data with Extension specialists throughout the region and will allow earlier transfer of information to crop protection specialists and producers.
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