We summarize field data on the species composition and seasonal phenology of the community of cerambycid beetles of east central Illinois. Data were drawn from field bioassays conducted during 2009–2012 that tested attraction of adult beetles of diverse species to a variety of synthetic pheromones and host plant volatiles. In total, 34,086 beetles of 114 species were captured, including 48 species from the subfamily Cerambycinae, 41 species from Lamiinae, 19 species from Lepturinae, 2 species from Spondylidinae, and 1 species each from Necydalinae, Parandrinae, Prioninae, and Disteniidae. Most of the best-represented species were attracted to pheromones that were included in field experiments, particularly species that use (R)-3-hydroxyhexan-2-one as a pheromone component. The species captured and their patterns of abundance and seasonal phenology were similar to those in an earlier study conducted in Pennsylvania. The most abundant species identified in both studies included the cerambycines Elaphidion mucronatum (Say), Neoclytus acuminatus acuminatus (F.), Neoclytus mucronatus mucronatus (F.), and Xylotrechus colonus (F.). Cerambycine species became active in an orderly progression from early spring to late fall, whereas most lamiine species were active in the summer and fall, and lepturine species were limited to the summer. Potential cross attraction between some cerambycine species that shared pheromone components may have been averted by differences in seasonal activity period and by minor pheromone components that acted as synergists for conspecifics, antagonists for heterospecifics, or both. These results provide quantitative data on the abundance and seasonal phenology of a large number of species.