| abstract | The Ixodes vector of human babesiosis in the northeastern United States represents a new species. All active stages of this tick, designated Ixodes dammini, n. sp., are described and compared with I. scapularis Say and I. muris Bishopp & Smith. In the Nantucket babesiosis focus, adult I. dammini most commonly feed on deer; larvae and nymphs are numerous on mice. Throughout the recorded species range (coastal areas in New Jersey, New York, Connecticut, Rhode Island, and Massachusetts; as well as Wisconsin and Ontario), each active stage feeds on a variety of vertebrates. |