Three buprestid species, Actenodes acornis (Say, 1836), Dicerca asperata (Laporte et Gory, 1837), and Dicerca lepida LeConte, 1857, are newly recorded from Canada on the basis of a collection of 57 buprestid specimens taken from females of the crabronid wasp Cerceris fumipennis Say, 1837 in Rondeau Provincial Park, Chatham-Kent region, Ontario, in July 2004. Nine additional buprestid species were taken from wasps that were intercepted as they approached their nests, demonstrating the effectiveness of C. fumipennis nest sites as sampling stations for buprestid beetles. We suggest that this sampling method could be applied to efficiently monitor the spread of the emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) in eastern North America.