|Haley, Scott - COLORADO STATE UNIVERSITY|
|Peairs, Frank - COLORADO STATE UNIVERSITY|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 15, 2005
Publication Date: October 6, 2006
Citation: Burd, J.D., Porter, D.R., Puterka, G.J., Haley, S.D., Peairs, F.B. 2006. Biotypic variation amoung North American Russian wheat aphid (Homoptera: Aphididae) populations. Journal of Economic Entomology. 99(5):1862-1866. Interpretive Summary: Interpretive Summary for: Burd, J.D., D.R. Porter, G.J. Puterka, S.D. Haley, and F.B. Peairs. Biotypic variation among North American Russian wheat aphid populations. The Russian wheat aphid is a serious pest of wheat and barley in the western United States. Host plant resistance has served as the cornerstone for managing Russian wheat aphids in areas where it is a perennial pest. The recent discovery of a new Russian wheat aphid biotype has jeopardized the durability and continued success of plant resistance as a management tool. In the present study, we assessed the relative amount of biotypic diversity among Russian wheat aphid populations collected from cultivated wheat and barley. Aphids were sampled from May through June 2002 and August 2003, from 74 wheat and barley fields from seven counties within four states. The sample locations were selected to encompass the peripheral margins of the primary latitudinal range of the RWA in the United States. All known sources of Russian wheat aphid resistance were used to develop a biotype matrix that was based upon differential damage responses induced by aphid feeding. Based upon this damage scheme, three new biotypes were identified, one of which was virulent to all known resistance sources. Plant resistance will continue to be an important Russian wheat aphid pest management tool, however, the future success of breeding programs will depend upon the continual monitoring of extant biotypic diversity.
Technical Abstract: Technical Abstract for: J.D. Burd, D.R. Porter, G.J. Puterka, S.D. Haley, and F.B. Peairs. Biotypic variation among North American Russian wheat aphid populations. The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), has been a major economic pest of small grains in the western United States since its introduction in 1986. Recently, a new RWA biotype was discovered in southeastern Colorado that damaged previously resistant wheat. Biotype development jeopardizes the durability of plant resistance, which has been a cornerstone for RWA management. Our objective was to assess the relative amount of biotypic diversity among RWA populations collected from cultivated wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). We conducted field surveys from May through June 2002 and August 2003 from 7 counties within Texas, Kansas, Nebraska, and Wyoming. Based upon a foliar chlorosis damage rating, three new RWA biotypes were identified, one of which was virulent to all known sources of RWA resistance. The future success of RWA-resistance breeding programs will depend upon the continual monitoring of extant biotypic diversity and determining the ecological and genetic factors underlying the development of RWA biotypes.