Barley yellow dwarf virus (BYDV) is a globally distributed pathogen of grasses that is transmitted by aphids. Little research has been done examining the response of aphids to different host grasses in naturally mixed communities. We measured the short-term fecundity of the aphid Rhopalosiphum padi, a widely distributed vector of BYDV, on a broad array of Oregon Poaceae in field and laboratory experiments to quantify the effect of host grass life history, provenance, phylogeny, and nutrient status on the number of nymphs produced. In both field and laboratory trials aphids had significantly higher rates of fecundity on annuals over perennials regardless of host grass provenance, phylogeny, or age class (in the case of perennials). Nitrogen addition resulted in higher aphid short-term fecundity. Thus, host life history and nitrogen status have an influence on the number of vector insects within a community. This suggests that the presence of infected annual host grasses in a community may cause an increase in overall viral prevalence.