Nymphs of Schizaphis graminum (Rodani), Diuraphis noxia (Mordvilko), and Rhopalosiphum padi (L.) were released as conspecific and heterospecific pairs on wheat plants, Triticum aestivum L. (cv. TAM 107) as first and fourth instars.  We evaluated their survival, developmental time, fecundity, intra-plant movement, and affinity to plant tissues.  Survival of first instars to maturity averaged 90-100% across all pair combinations.  Diuraphis noxia developed faster as conspecifics than in any heterospecific combination, and as conspecifics feeding on the same plant tissue than on different tissues.  Fecundity of S. graminum was higher for conspecifics that developed on the same plant tissue than those feeding separately. Diuraphis noxia experienced delayed development feeding in tandem with S. graminum, and reduced fecundity with both S. graminum and R. padi.  Both D. noxia and R. padi changed position on the plant more often when developing with S. graminum.  Survival of second generation S. graminum nymphs was reduced when this species developed and reproduced in tandem with R. padi.  Preferred feeding locations were S. graminum - primary leaf, D. noxia - tertiary leaf and R. padi -stem and these were not altered in any heterospecific combinations.  Heterospecific aphids had no impact on fecundity or progeny survival in any species combination when fourth instars developed and reproduced on plants not previously exposed to aphid feeding, confirming the role of systemic, aphid-induced, plant physiological changes in mediating the effects observed with first instars.