Dromaeolus americanus 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 : 24-25

Dromaeolus americanus Otto, Muona and Córdoba-Alfaro , new species

Figures 54–55

Diagnosis. This new eucnemid species can be readily distinguished from any ornate members of Dromaeolus present in Costa Rica by its elytral vittae and smaller size. The elytral vittae are very similar to an Amazonian eucnemid, D. batesii Bonvouloir , but D. americanus differs by its smaller size.

Type material. Male holotype: “ COSTA RICA: Heredia; Est.Bio. La Selva , 50–; 150 m 10°26′N 84°01′W; Proy. ALAS, INBio-OET” / “M/06/198; 01 Septembre 1993; Bosque primario” / “ HOLOTYPE:; Dromaeolus ; americanus ♂; Otto, Muona & Córdoba-Alfaro; Det. R. L. Otto; 2019” (red printed label). Holotype to be deposited in INBC.

Paratype. 1 ♂: COSTA RICA: “COSTA RICA: Heredia; Est.Bio. La Selva , 50–; 150 m 10°26′N 84°01′W; Proy. ALAS, INBio-OET” / “M/01/320; 15 Enero 1994; Parcelas sucesionales” / “ PARATYPE:; Dromaeolus ; americanus ♂; Otto, Muona & Córdoba-Alfaro; Det. R. L. Otto; 2019” (yellow printed label) . Paratype to be deposited in INBC.

Description. Male holotype: Length, 4.5 mm. Width, 1.0 mm. Body elongate; black; antennae black; femur and tibiae black, tarsi black; head and pronotum clothed with short, recumbent silver-colored setae more apparent along base and lateral sides of pronotum, elytra with silver-colored setae more apparent with comma-shaped vittae at humeri, wide band across the apical 1/3 of each elytron, short, narrow patch along elytral suture just below scutellar shield ( Figure 54 ). Head: Surface dullish, subspherical with closely spaced punctures; frons convex, simple with slight circular impression above interantennal carina; interantennal carina present; apical margin of frontoclypeal region weakly trilobed, more than 2 times wider than base; mandibles stout, bidentate, densely punctate. Antenna: Filiform from flagellomeres I–IX, attaining nearly 1/3 the length of the body, never passed beyond pronotal hind angles; flagellomere I longer than wide, longer than II; flagellomeres II–VIII each quadrate, sub-equal; flagellomere IX slightly longer than VIII. Pronotum: Surface dullish, with evenly dispersed punctures; slightly longer than wide, with well-developed, sharp hind angles; sides arcuate above pronotal hind angles; disc convex without shallow median groove or circular fovea; base sinuous, with delicate short median groove. Scutellar shield: Quadrate, sub-triangular, shallowly punctate and distally rounded. Elytra: Very shallow striae indicated; interstices slightly elevated; surfaces dullish, transversely rugose at basal 1/4, closely punctate elsewhere. Legs: First tarsomere longer than the combined lengths of the remaining four on meso- and metatarsi; tibiae rounded in cross section; metatarsomeres I–III simple; metatarsomere IV excavated; metatarsomere V short with simple claws. Venter ( Figure 55 ): Closely punctate, with short, recumbent silver-colored setae; hypomeron with basally opened, lateral antennal grooves; metepisterna parallel-sided; elytral epipleura punctate; metacoxal plates medially 3.0–6.0 times wider than laterally.

Variation. The male paratype measured 5.0 mm long and 1.0 mm wide. It is slightly longer than and just as wide as the holotype. Interantennal carina is more apparent than the holotype. A circular impression above the interantennal carina is also more apparent than the holotype.

Distribution. This species is known from two specimens taken from La Selva within the province of Heredia.

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

Etymology. The specific epithet is named after America, a name first used shortly after Christopher Columbus’ voyage to the new world, in which the name derives from Amerigo Vespucci, an Italian explorer who explored the new continents years later.

Figures

Figures 54–57. Costa Rican Dromaeolus species. 54) Dromaeolus americanus sp. nov., dorsal habitus. 55) Dromaeolus americanus sp. nov., ventral habitus. 56) Dromaeolus brunneus sp. nov., male holotype, dorsal habitus. 57) Dromaeolus brunneus sp. nov., male holotype, ventral habitus. (Scale: 54–57 = 1.0 mm)