The mandibles, stridulatory peg, and male genitalia of the adults of eight species of Ochodaeus found in the United States have useful characters for the delineation of species and are described and figured. The most useful taxonomic feature of the male genitalia is the aedeagal sac. The taxonomic characters of Ochodaeus are reviewed and a key to the species of the O. pecloralis species complex is presented.
The Ocliodaeus pecloralis species complex is erected to contain the nominate species O. pecloralis LeConte and two new species which are described. The other five species considered are O. biariuulus LeConte, O. inarmatus Schaeffer, O. kansanus Fall, O. praesidii Bates, and O. simplex LeConte. A lectotype is designated for O. inarmatus Schaeffer.