Functioning of plant-aphid-natural enemy interactions may be associated with the structure and composition of withinfield vegetation, neighborhood fields and field borders, and the regional plant community of cropped and noncropped areas. Farmand region-scale vegetation in the wheat-growing area of the North American Great Plains was hypothesized to effect the abundance of two hymenopteran para...

The effects of infestation by the bird cherry-oat aphid (BCA), (Rhopalosiphum padi L) and the Russian wheat aphid (RWA) (Diuraphis noxia Mordvilko) on callose deposition and transcription of genes related to callose accumulation were investigated in barley (Hordeum vulgare L. cv. Clipper). The BCA, which gives no visible symptoms, induced very limited callose deposition, even after 14 days of i...

the russian wheat aphid (rwa), diuraphis noxia (mordvilko), is a significant insect pest of wheat worldwide. the objective of this study was to assess the genetic variation within and between f2-derived families for reaction to rwa using f3 and f4 families originating from individual f2 plants of a cross between the susceptible line (synthetic hexaploid-11) and the resistance cultivar (‘halt’)....

in recent years, the russian wheat aphid, has been included worldwidely in the list of the important pests of cereals, particularly wheat plants. in addition to direct serious damage, the aphid is the main vector of barley yellow dwarf, barley mosaic, and sugarcane mosaic viruses. the pest was reported from east azarbaidjan province (iran) a few years ago and it is now widespread in tabriz,...

Wheat, Triticum aestivum L., with Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae) resistance based on the Dn4 gene has been important in managing Russian wheat aphid since 1994. Recently, five biotypes (RWA1-RWA5) of this aphid have been described based on their ability to differentially damage RWA resistance genes in wheat. RWA2, RWA4, and RWA5 are of great concern beca...