Absensiugum Otto, Muona and Córdoba-Alfaro, 2023

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 : 20

Absensiugum Otto, Muona and Córdoba-Alfaro , new genus

Type species. Absensiugum brunneum new species, by present designation.

Diversity and distribution. Absensiugum new genus is a genus consisting of two species distributed in the Caribbean, Nearctic and Neotropical regions. The new species was found in two locations within a single area in Costa Rica. The second species is distributed in the Caribbean region and southeastern United States.

Description. Male. Body elongate, approximately 3.5 times longer than wide, dorsally convex and ventrally well sclerotized. Head: Hypognathous, with short, recumbent setae. Antennae tubular, filiform with 11 antennomeres, setose; scape 3.0 times longer than pedicel; pedicel globular, shorter than flagellomere I; flagellomere I longer than II; flagellomeres II–IV sub-equal in length and rounded in cross section; flagellomeres V–VIII sub-equal in length and rounded in cross section; flagellomere IX longer than VIII. Eyes round, well developed, enlarged, not incised. Frontoclypeal region subtriangular, apically trilobed, about 2.5 times wider than base. Mandibles well developed, stout, bidentate. Maxillary and labial palpi concealed behind mandibles. Labrum concealed. Pronotum: Subparallel-sided, convex and setose. Longer than wide, with moderately sized pronotal hind angles. Lateral pronotal ridge entire, straight. Disc convex. Base sinuous. Scutellar shield: Setose, short, sub-triangular. Elytron: Elongate, convex, setose. Disc with striae indicated as punctate lines. Interstices slightly elevated. Cavities absent near elytral apices. Legs: Prothoracic legs shortest, metathoracic legs longest. Protibia apically rounded, setose, with one apical spur. Lateral sides of meso- and metatibiae with setae and transverse row of spine combs. Metatarsi, including claws, as long as tibia. Protarsomere I with straight, basal sex combs. First metatarsi as long as combined length of remaining four. Metatarsi I–III simple. Metatarsus IV excavate-emarginate, as wide as III. Metatarsus V elongate. Pretarsal claws basally toothed. Tarsal formula 5-5-5. Venter: Surface with recumbent setae. Prosternal peg basally narrow, elongate. Notosternal suture as long as the hypomeral base. Hypomeron without medially defined antennal ridge, surface smooth along lateral ridge, rest punctate. Epipleura simple, not grooved. Metepisterna parallel-sided. Metacoxal plate medially 3.0–6.0 times wider than laterally. Tarsal grooves absent on meso- and metasterna. Abdomen with 5 visible ventrites, convex medially. Last visible ventrite rounded caudally.

Etymology. The new generic name is a combination of two Latinized words, absens, which means absent and iugum which means ridge, due to the missing medial antennal ridge of the hypomeron. Gender neuter.

Note. During the course of the study, R. Otto discovered a pair of Costa Rican beetles superficially resembling the Nearctic species, Dromaeolus teres (Horn) . Upon further examination, these two species were found to share the same morphological attributes, resulting in our decision to create a new group name, Absensiugum new genus, for these species. Therefore, we propose to transfer Nematodes teres Horn to the new group, hereby recognized as Absensiugum teres (Horn) new combination.