Absensiugum brunneum 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 : 21-22

Absensiugum brunneum Otto, Muona and Córdoba-Alfaro , new species

Figures 37–40

Diagnosis. The new species differ from A. teres by its antennal segments; stouter, quadrate in the new species and longer than wide in A. teres . Additionally, habitus coloration will further distinguish the new species from A. teres ; dark brown in the new species, reddish-brown in A. teres .

Type material. Male holotype: “ COSTA RICA, Heredia; Est.Bio. La Selva, 50–; 150 m, 10°26′N 84°01′W; Apr 2000, INBio-OET” / “M/01/236; 15 Octubre 1993; Parcelas sucesionales” / “ HOLOTYPE:; Absensiugum ; brunneum ♂; Otto , Muona & Córdoba-Alfaro; Det. R. L. Otto; 2019” (red printed label). Female allotype: “ COSTA RICA, Heredia; Est.Bio. La Selva , 50–; 150 m, 10°26′N 84°01′W; Apr 2000, INBio-OET” / “M/12/390; 04 Abril 1994; Bosque primario” / “ ALLOTYPE: Absensiugum ; brunneum ♀; Otto, Muona & Córdoba-Alfaro; Det. R. L. Otto; 2019” (yellow printed label). Holotype and allotype are to be deposited in INBC .

Description. Male holotype: Length 3.0 mm, width 0.75 mm. Body color uniformly dark brown ( Figure 37 ). Head: Subspherical, without carina or fovea on frons; interantennal carina absent; surface dullish; punctures deep, closely spaced; eyes protuberant. Antennae: Dark reddish-brown; filiform, about 1/3 of body length; flagellomeres II–IV quadrate, sub-equal; flagellomeres V–VIII each slightly larger than IV, quadrate; flagellomere IX larger than VIII; lateral carina absent on flagellomeres II–VIII. Pronotum: Surface dullish, with somewhat elongate, yellow recumbent setae; punctures deep, closely spaced, almost rugose; longer than wide, with moderate, sharp hind angles; sides subparallel, sinuous; disc convex; base sinuous. Scutellar shield: Somewhat shiny, setose, punctures deep, close, subtriangular and distally rounded. Elytron: Convex, elongate, gradually narrowed from humeri to apices; conjoined tightly at apex; somewhat shiny, with elongate, yellow recumbent setae; length 2.0 mm, width 0.375 mm at humeri; humeri with punctate striae; disc with punctate striae; interstices slightly elevated, transversely rugose; apices without cavities. Legs: Femora and tibiae dark brown; tarsi dark reddish brown; surface somewhat shiny; punctures shallow, with yellow recumbent setae. Venter ( Figure 38 ): Dark brown; surface somewhat shiny, with elongate, yellow recumbent setae; punctate, except along lateral side of hypomeron. Aedeagus ( Figure 39 ): Elongate, dorsally flattened, sinuate, apically narrowed; median lobe free, short, apically rounded; parameres apically elongate, rounded, longer than median lobe, with lateral tooth; secondary lateral lobe absent; basal piece elongate, apically rounded.

Female allotype ( Figure 40 ): Length, 4.0 mm. Width, 1.0 mm. Antennae filiform, about 1/3 the length of the body; flagellomere I longer than wide, longer than II; flagellomere II–IV slightly longer than wide, sub-equal; flagellomeres V–VIII each slightly longer than IV, longer than wide, sub-equal. Antennae reddish-brown. Legs reddish brown. Lateral antennal grooves deeper, surfaces smooth, ridge medially undefined.

Distribution. This new eucnemid species is known from two localities at La Selva (successional plot and primary forest) within Costa Rica.

Biology. The holotype was taken from a successional plot. The allotype was taken from a primary forest. Larvae and pupae are unknown.

Etymology. The specific epithet is derived from the dark brown coloration of the beetle.

Figures

Figures 35–39.Costa Rican macraulacine eucnemids. 35) Isarthrus striatus sp. nov., dorsal habitus. 36) Isarthrus striatus sp. nov., ventral habitus. 37) Absensiugum brunneum sp. nov., male holotype, dorsal habitus. 38) Absensiugum brunneum sp. nov., male holotype, ventral habitus. 39) Absensiugum brunneum sp. nov., Male aedeagus, dorsal view. (Scale: 35–36 = 5.0 mm; 37–39 = 1.0 mm)

Figures 40–43. Costa Rican macraulacine eucnemids. 40) Absensiugum brunneum sp. nov., female allotype, dorsal habitus. 41) Dromaeolus ambiguus, dorsal habitus. 42) Dromaeolus cinerescens, dorsal habitus. 43) Dromaeolus dilutipes, dorsal habitus. (Scale: 40–43 = 1.0 mm)