Since its discovery in 2000, the soybean aphid (Aphis glycines Matsumura) has become the most economically important pest of US soybean production, and classical biological control is being attempted in several Midwest states. Rising concerns over non-target effects in classical biological control have resulted in an increased effort to reduce such effects through the study of potential non-target organisms. As part of a multi-state effort to assess potential non-target effects in soybean aphid biological control, a survey of native aphids and their associated natural enemies was conducted at six Indiana prairies in 2006 and 2007. The aphid survey provided information on aphid species present in Indiana and the natural enemies of these aphids, particularly parasitoids. Factors such as the taxonomy, phenology, abundance, distribution, and natural enemy load were used in assessing the risk of non-target effects on individual aphid species. Results from the aphid survey and risk assessment will be discussed.