Russian wheat aphid Diuraphis noxia (Kurdjumov) is widely established in wheat-growing countries where it causes significant economic losses. The development and use of Russian wheat aphid (RWA)-resistant wheat varieties has been constrained by the variation in resident RWA populations and the evolution of virulent biotypes. An experiment was set up at the Kenya Agricultural and Livestock Resea...

Russian wheat aphid, Diuraphis noxia (Mordvilko), feeding injury on 'Betta' wheat isolines with the Dn1 and Dn2 genes was compared by assessing chlorophyll and carotenoid concentrations, and aphid fecundity. The resistant Betta isolines (i.e., Betta-Dn1 and Betta-Dn2) supported similar numbers of aphids, but had significantly fewer than the susceptible Betta wheat, indicating these lines are re...

230 Journal of Plant Registrations, Vol 2, No. 3, September 2008 Devastating yield losses occurred in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) in the western United States within 2 yr after the fi rst appearance of the Russian wheat aphid [RWA; Diuraphis noxia, (Mordvilko)] in 1986 (Porter et al., 1999). Screening of the entire USDA-ARS National Small Grains Collection of H....

The abundance and distribution of microsatellites, or simple sequence repeats (SSRs) were explored in the expressed sequence tag (EST) and genomic sequences of the pea aphid, Acyrthosiphon pisum (Harris), and the green peach aphid, Myzus persicae (Sulzer). A total of 108 newly developed, together with 40 published, SSR markers were investigated for their cross-species transferability among six ...

Efficacy of Beauveria bassiana (Hyphomycetes) for control of Russian wheat aphid (Homoptera: Aphididae) on resistant wheat under field conditions Justin L. Hatting a; Stephen P. Wraight b;Ray M. Miller c a Agricultural Research Council Small Grain Institute, Bethlehem, South Africa b Plant Protection Research Unit, USDA-ARS, Ithaca, NY, USA c Pietermaritzburg, University of Kwa Zulu-Natal, Scot...

A 5 yr study in the semiarid wheat production region of eastern Washington documented the relative densities of pest aphids and their natural enemies in cereal production systems using on-farm replicated plots. The systems were reduced-tillage soft white winter wheat (SWW) (Triticum aestivum L.)—summer fallow rotation; no-till soft white spring wheat (SWS)— chemical fallow rotation; continuous ...

Russian Wheat Aphid Barley Yellow Dwarf Wheat Streak Mosaic Planting winter wheat as early as possible, particularly under dryland conditions, can increase yields by 10 percent or more, but also increases the risk for several serious pest problems that can cause major yield losses. Early planting can create a situation called a green bridge where pests and disease move from maturing cereals or ...

The biotypic diversity of the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), was assessed in five isolates collected in Colorado. Three isolates, RWA 1, RWA 2, and an isolate from Montezuma County, CO, designated RWA 6, were originally collected from cultivated wheat, Triticum aestivum L., and obtained from established colonies at Colorado State University. The fourth ...

Infocrop, a generic crop growth model was used to simulate the effect of Russian wheat aphid, Diuraphis noxia (Mordvilko) damage on winter wheat at Fort Collins and Akron, Colorado state, USA,. Observed and simulated yield reductions in four experiments over a period of two years were found to be closely related (R = 0.85). The aphid damage mechanisms coupled to the crop growth model could thus...

The impact of feeding injury by the Russian wheat aphid, Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae), and bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae) on susceptible and resistant wheat, Triticum aestivum L., near-isogenic lines 'Tugela' (susceptible), Tugela-Dn1 (antibiotic), Tugela-Dn2 (tolerant), and Tugela-Dn5 (antixenotic) was evaluated by assessing photosyn...