Despite a relatively recent taxonomic revision, North American weevils of the economically important genus Curculio remain poorly characterized and difficult to distinguish. Given herein is an illustrated key to the 15 species found east of the Mississippi River, including the putatively extinct C. caryatrypes (Boheman) or greater chestnut weevil. This is necessarily a complex key using multiple characteristics, designed to minimize or eliminate difficulties in identification posed by extremes in structural variation in both males and females. Curculio ordinatus (Casey) is transferred from synonymy with C. nasicus (Say) to synonymy with C. strictus (Casey), new synonymy.
