The mirid fauna associated with oldfield goldenrods (Solidago spp.) was sampled from May 10-Oct. 25, 1977 in Ithaca, New York USA . Species (23) belonging to 16 genera were recorded; 97% of all individuals (1099) belong to 6 genera (Lygus, Slaterocoris, Lopidea, Plagiognathus, Adelphocoris and Polymerus). The tarnished plant bug, Lygus lineolaris, was the most common species. The dominant mirids can be divided into 2 fairly distinct guilds, L. lineolaris, 2 Plagiognathus spp. and A. rapidus feeding primarily on goldenrod flowers and 3 Slaterocoris spp., Lopidea media and Polymerus venaticus feeding on the immature foliage. The phenological pattern exhibited by these species can be broadly explained by this difference in resource utilization. Observations on the biology of certain species are presented.