A review of Nearctic Lathrobium (Coleoptera, Staphylinidae), with revision and descriptions of new flightless species from the mountains of the southeastern U. S. Author Haberski, Adam https://orcid.org/0000-0002-4062-178X Department of Plant & Environmental Sciences, Clemson University, Clemson, SC 29634 - 0310, USA ahaberski@gmail.com Author Caterino, Michael S. https://orcid.org/0000-0002-2597-5707 Department of Plant & Environmental Sciences, Clemson University, Clemson, SC 29634 - 0310, USA text ZooKeys 2024 2024-04-25 1198 193 277 http://dx.doi.org/10.3897/zookeys.1198.118355 journal article http://dx.doi.org/10.3897/zookeys.1198.118355 1313-2970-1198-193 59053839702C46C9B0F6AA37C61C0E45 0257BC4776C25532B6CEB2BDECD8E7AB Lathrobium (Lathrobium) fauveli Duvivier, 1883 Lathrobium fauveli Duvivier, 1883: 161. Lathrobium simplex LeConte, 1880: 176 (preoccupied). Lathrobium gravidulum Casey, 1905: 90. New synonym. Lathrobium innocens Casey, 1905: 89. New synonym. Lathrobium neglectum Casey, 1905: 89. New synonym. Type material. Lectotype , Lathrobium fauveli Duvivier, herein designated (MCZ): Faded disc / "♂ / [handwritten] L. simplex Lec. / [red] Type 6451 / Lectotype Lathrobium simplex LeConte Desg. Haberski & Caterino." Lectotype , Lathrobium gravidulum Casey, herein designated (USNM): "Mass / ♂ / CASEY bequest 1925 / [red] TYPE USNM 38124 / [handwritten] Lathrobium gravidulum / Lectotype Lathrobium gravidulum Casey Desg. Haberski & Caterino." Lectotype , Lathrobium innocens Casey, herein designated (USNM): "Marq / ♂ / CASEY bequest 1925 / [red] TYPE USNM 38126 / [handwritten] Lathrobium innocens / Lectotype Lathrobium innocens Casey Desg. Haberski & Caterino." Lectotype , Lathrobium neglectum Casey, herein designated (USNM): "RI / CASEY bequest 1925 / [red] TYPE USNM 38125 / [handwritten] Lathrobium neglectum / Lectotype Lathrobium neglectum Casey Desg. Haberski & Caterino." Other material. Canada : Nova Scotia : Queens Co. : Kejimkujik National Park , 09 May 1999 , J. C. Ciegler (1, CUAC) . Quebec : MRC de Portneuf : Pont-Rouge , 22 Apr 2023 , N. Bedard , sifted from dead leaves in a sandpit (1, NBC) . USA : Connecticut : New Haven Co. New Haven (6, USNM) . Massachusetts : ' Mass. ' (1, MCZ); ' Mass. ' (4, USNM) . Michigan : Marquette Co. : Marquette (1, USNM) . New Hampshire : Grafton Co. : Downes Brook , Potash Mountain , 05 Jun 2021 , A. Haberski , along creek edge (1, CUAC); Coos Co. : Mount Washington 2700' elev. (1, UNHC); Strafford Co. : Spruce Hole Conservation Area , D. S. Chandler (1, UNHC); Grafton Co. : Hubbard Brook Experimental Forest, D. S . Chandler (1, UNHC) . Rhode Island : 'R. I.' (1, USNM). Diagnosis. This species closely resembles L. crurale and can be distinguished from that species by the characters discussed in the diagnosis of L. crurale . Description. Body length 8 mm; body coloration dark red, appendages lighter red. Gular sutures parallel, widely separate; antennomeres V-VIII longer than wide. Elytra as long as pronotum. Females with paraprocts undivided, apices longer than basal portion; sternite VIII conical. Ventral process of aedeagus with distinctive apical tooth (Fig. 38 ). Distribution. Canada: AB, BC, MB, NB, NF, NS, ON, PE, QC, SK ( Bousquet et al. 2013 ). USA: CT, MA, ME, MI, NH, RI, WI ( Casey 1905 ; Newton 2022 ). Remarks. We reduce Lathrobium gravidulum , Lathrobium innocens , and Lathrobium neglectum to synonymy with Lathrobium fauveli , based on the absence of clear distinguishing characters. Lathrobium neglectum and L. innocens were distinguished from L. fauveli based on larger emarginations in male sternite VIII. However, we found no difference in size among species. Lathrobium gravidulum was distinguished based on subtle differences in punctation and the coloration of appendages, but neither are consistent. Examination of the genitalia found no differences in either aedeagi or female terminalia.