Cerceris fumipennis is a colonial wasp that preferentially preys on native and nonnative Buprestidae, which includes emerald ash borer (EAB), Agrilus planipennis. EAB is currently a major threat to ash tree (Fraxinus spp.) populations in the northeast United States and parts of Canada, and C. fumipennis is used for bio-surveillance of this destructive pest. This wasp catches, stings, and paralyzes buprestid and other beetles that then serve as a live food source for the wasp larvae. Two large colonies of C. fumipennis were monitored during the summer of 2013 in Merrimack County, NH, USA, to determine seasonality of C. fumipennis and to document the prey species and the levels of paralyzation of these species. There were 853 individuals consisting of 34 buprestid species and one chrysomelid species taken from C. fumipennis females. Eleven of these species had paralyzation rates of less than 100%, consisting of 11% of the total collected prey. Chrysobothris verdigripennis, Agrilus carpini, Actenodes acornis are new state records for New Hampshire.