Isarthrus LeConte, 1852

Otto, Robert L., Muona, Jyrki & Córdoba-Alfaro, Jim, 2023, A new genus and sixteen new species of false click beetles (Coleoptera: Eucnemidae) described from the Heredia Province of Costa Rica with several additional records from the Osa Peninsula and Panama, Insecta Mundi 2023 (991), pp. 1-36 : 18

Genus Isarthrus LeConte, 1852

Diversity and distribution. Historically, Isarthrus is a small group consisting of two species found in the Nearctic region, north of Mexico. A third species described here, is the first outside the Nearctic region.

Diagnosis. Apical margin of frontoclypeal region feebly trilobed and more than twice as wide as the distance between antennal sockets; well-developed basally open lateral antennal grooves present; male protarsomere I simple, with basal sex combs; metacoxal plates medially 3.0–6.0 times wider than laterally; elytral epipleura evenly punctate; last visible ventrite either rounded or slightly emarginate; tarsal claws simple; lateral surfaces of meso- and metatibiae with setae and transverse rows of spine combs; male aedeagus dorsoventrally compressed, without secondary lateral lobes; median lob simple, with moderately and narrowly bifurcate apices; lateral lobes simple, entire; aedeagal flagellum simple.