Quirsfeldia stethonoides 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 : 11

Quirsfeldia stethonoides Otto, Muona and Córdoba-Alfaro , new species

Figures 20–22

Diagnosis. Generic character features like caudally obliterated notosternal antennal grooves, parallel-sided metacoxal plates and apical margin of the frontoclypeal region being less than 2.0 wider than the base will distinguish the new species from all known species within the tribe in Costa Rica.

Type material. Female holotype: “ COSTA RICA: Heredia; Est.Bio. La Selva , 50–; 150 m 10°26′N 84°01′W; Proy. ALAS, INBio-OET” / “M/06/170; 03 Agosto 1993; Bosque primario” / “ HOLOTYPE: Quirsfeldia ; stethonoides ♀; Otto, Muona & Córdoba-Alfaro; Det. R. L. Otto; 2019” (red printed label). Holotype to be deposited in INBC.

Description. Female holotype: Length, 3.0 mm. Width, 1.0 mm. Body elongate; uniformly dark brownish black; antennae dark brownish black; legs brown; head, pronotum and elytra clothed with short, recumbent yellowish setae ( Figure 20 ). Head: Surface densely punctate, somewhat dullish, subspherical; frons convex, with delicate median fovea above frontoclypeal region; apical margin of frontoclypeal region rounded, less than 2.0 times wider than base; mandibles stout, bidentate, densely punctate. Antenna: Asymmetrically serrate from flagellomeres II– IX, presumably attaining about 1/3the length of the body, never beyond pronotal hind angles; flagellomere I longer than II; flagellomere II shorter than I and III, quadrate; flagellomeres III–VII each sub-equal, wider than long; flagellomeres VIII–IX missing on right antenna; flagellomeres VI–IX missing on left antenna. Pronotum: Surface somewhat dullish, granulose; slightly longer than wide, with moderate, sharp hind angles; lateral sides parallel-sided at basal 2/3, arcuate at apical 1/3; disc convex with short, delicate median groove above scutellar shield; anterior lateral pronotal ridge short, arched, ventrally bent; posterior lateral pronotal ridge elongate, extending almost to caudal end ( Figure 21 ); base sinuous. Scutellar shield: Short, sub-triangular, shallowly punctate, with median groove and distally rounded. Elytra: Shallow striate indicated; interstices slightly elevated; surfaces shiny, transversely rugose at basal 1/2, dense, rugose at apical 1/2. Legs: First tarsomere shorter than the combined lengths of the remaining four on meso- and metatarsi; tibiae rounded in cross section; metatarsomeres I–IV simple; metatarsomere IV very short; metatarsomere V elongate with simple claws. Venter ( Figure 22 ): Closely punctate, with short, recumbent yellowish setae; hypomeron with caudally obliterated, poorly defined notosternal antennal grooves; metepisterna parallel-sided; elytral epipleura punctate; metacoxal plates parallel-sided.

Distribution. This eucnemid species is only known from its type location in Costa Rica.

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

Etymology. The specific epithet is derived from its similar appearance to the Eucnemine genus, Stethon LeConte.

Subfamily Macraulacinae Fleutiaux, 1923

Diagnosis. Form oblong, elongate or obtuse; antennomeres usually sexually dimorphic; mandibles either stout with a basal tooth or slender without teeth; simple lateral pronotal ridge present; hypomeron either simple, with basally closed lateral antennal grooves or with basally open lateral antennal grooves; legs slender; prothoracic tibiae with one apical spur; lateral surfaces of mesothoracic and metathoracic tibiae usually with transverse rows of spines; tarsomere IV often bilobed; tarsal claws either simple or basally toothed; prothoracic tarsomere I usually with basal sex combs in males; male aedeagus with dorsally open basal piece; median lobe simple, with solidly fused slender basal struts; fused to lateral lobes; lateral lobes entire, either with notched or apically deeply and narrowly bifurcate; bursa either simple or divided; spermatheca tripartite, sclerotized, divided ( Muona 1993; Otto 2016).

Tribe Macraulacini Fleutiaux, 1923

Diagnosis. Form oblong, elongate or obtuse; flagellomeres usually sexually dimorphic; mandibles either stout with a basal tooth or slender without teeth; simple lateral pronotal ridge present; hypomeron either simple, with basally closed lateral antennal grooves or with basally open lateral antennal grooves; legs slender; prothoracic tibiae with one apical spur; lateral surfaces of mesothoracic and metathoracic tibiae usually with transverse rows of spines; tarsomere IV often bilobed; tarsal claws either simple or basally toothed; prothoracic tarsomere I usually with basal sex combs in males; male aedeagus with dorsally open basal piece; median lobe simple, with solidly fused slender basal struts, fused to lateral lobes; lateral lobes entire, either with notched or apically deeply and narrowly bifurcate; bursa either simple or divided; spermatheca tripartite, sclerotized, divided ( Muona 1993; Otto 2017c).

Figures

Figures 17–22. Costa Rican Eucnemidae. 17) Adelothyreus totus sp. nov., dorsal habitus. 18) Adelothyreus totus sp. nov., pronotal lateral habitus. 19) Adelothyreus totus sp. nov., ventral habitus. 20) Quirsfeldia stethonoides sp. nov., dorsal habitus. 21) Quirsfeldia stethonoides sp. nov., pronotal lateral habitus. 22) Quirsfeldia stethonoides sp. nov., ventral habitus. (Scale: 17–22 = 1.0 mm)