Nematodes thoracicus Otto, 2023

Otto, Robert L., 2023, The false click beetles (Coleoptera: Elateroidea: Eucnemidae) of the Dominican Republic. Part I: A look into the past, Insecta Mundi 2023 (973), pp. 1-23 : 20

Nematodes thoracicus Otto , new species

Fig. 26–27

Holotype. Embedded in ovoid Dominican Republic amber piece, 22 mm × 15 mm × 5 mm. Amber piece is clear yellow with small air bubbles and a few pieces of debris.

Diagnosis. Smaller size (3.25 mm) along with carinulate dorsolateral aspects of pronotum will distinguish the new species from all known Nematodes species.

Description. Length, 3.25 mm. Width, 1.0 mm. Habitus very elongate, narrow and tapering towards the elytral apex; luster uniformly metallic silver; antennae and legs metallic silver; head, pronotum and elytra clothed with very short, brown recumbent setae ( Fig. 26 ). Head: Closely punctate, subspherical with convex frons; surfaces shiny; apical margin of frontoclypeal region very weakly trilobed, about twice as wide as the base; mandibles stout, bidentate, densely punctate. Antennae: Weakly serrate, reaching about 1/3 the length of the body. Flagellomere I slightly longer than II; flagellomere III longer than II; flagellomeres IV–IX sub-equal, each longer than III. Pronotum: Closely punctate; surface shiny; longer than wide, with moderate, narrowed hind angles; basal three-fourths parallel-sided, sinuous; anterior portion of pronotum slightly arcuate; disc with oblong median impression; dorsolateral aspects carinulate; lateral sides with one ridge; hypomeron with extremely narrowed, well developed, basally open lateral grooves. Scutellum: Closely punctate, oblong, triangular and distally rounded. Elytra: Closely punctate; striae absent. Legs: First tarsomere shorter than 2–5 combined on mesothoracic and metathoracic tarsi; tibiae rounded in cross section; metatarsomeres I–III simple; metatarsomeres IV excavated and emarginated; metatarsomere V somewhat elongate with simple claws. Venter ( Fig. 27 ): Closely punctate, with recumbent short brown setae; metaepisternum parallel-sided; metacoxal plates medially 3.5 times as wide as laterally.

Etymology. Specific epithet is derived from the characteristics of the pronotum that set the species apart from any remaining species.

Figures

Figures 24–27. Dominican amber Eucnemidae. 24) Nematodes miocenensis Otto sp. nov., dorsal view. 25) Nematodes miocenensis Otto sp. nov., ventral view. 26) Nematodes thoracicus Otto sp. nov., dorsolateral view. 27) Nematodes thoracicus Otto sp. nov., ventral view. (Scale: 24–27 = 2.0 mm).