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Diuraphis was not well known until around the turn-of -the-century. Then outbreaks of D. noxia (the Russian wheat aphid) and D. tritici (the western wheat aphid) in Russia and the western United States, respectively, brought attention to the destructiveness of these aphids on wheat. In the latter part of this century, attention was once again focused on Diuraphis, especially D. noxia. Diuraphis noxia was first discovered in South Africa in 1978 (Durr 1983) and in the United States in 1986 (Stoetzel 1987). This aphid spread quickly and has been recorded throughout much of the wheat growing regions of the world. In the United States, its damage to wheat and barley was extensive and resulted in heavy crop losses in some fields (Stoetzel 1987). By 1993, D. noxia was a pest in 16 western states and caused cumulative losses exceeding $500 million dollars (Bernal et al. 1993). Probably because of the potential for economic losses, much of the literature on Diuraphis has concentrated primarily with D. noxia. However, more recently, G.-x. Zhang et al. (1991) gave a key to Diuraphis and discussed phylogenetic relationships. This work also included the descriptions D. agropyronophaga and D. elymophila. Kovalev et al. (1991) also provided a key to the Diuraphis apterous viviparous females and reviewed the Russian language literature. Descriptions, separate keys to apterae and alata, and illustrations for Diuraphis of Fennoscandia and Denmark were also provided by Heie (1992).
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 Diuraphis noxia
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