Mioxylobius bicolor 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 : 7-8

Mioxylobius bicolor Otto , new species

Fig. 1–3

Holotype. Embedded in ovoid Dominican Republic amber piece, 20 mm × 12 mm × 5 mm. Amber piece is clear yellow with small air bubbles and micro fractures.

Description. Length, 3.0 mm. Width, 1.0 mm. Elongate and tapering towards the elytral apex; head, elytra and venter dark black; pronotum, antennae and legs dark brown; head, pronotum and elytra with long black recumbent setae ( Fig. 1 ). Head: Subspherical; surfaces deeply punctate, shiny; remaining areas of head obscured by microscopic froth; dark black. Antennae ( Fig. 2 ): Loosely serrate, extending to pronotal hind angles; dark brown. Pronotum: Shiny; surfaces deeply and widely punctate; dark brown. Elytra: Shiny with deep, widely spaced punctures; dark black. Venter ( Fig. 3 ): Shiny; deeply punctate; dark black.

Etymology. Specific epithet is derived from its dark brown and black colorations.

Remarks. The extinct group belongs in the tribe Xylobiini based on its smaller size, simple hypomeron, cylindrical form and smaller flagellomere I. Lack of lateral ridges on the antennomeres, along with loosely serrate flagellomeres, places the group between Bioxylus Fleutiaux and Xylophilus Mannerheim. Mioxylobius new genus is distinguished by its much shorter flagellomere I compared with the pedicel or flagellomere II. Pedicel and flagellomere I are each short and sub-equal in both Bioxylus and Proxylobius Fleutiaux. Flagellomere I is slightly longer than the pedicel and flagellomeres II–V are tubular in Xylophilus . The presence of excavate-emarginate metatarsomere IV would suggest it belongs to Macraulacini , but the tarsal structure is also present in extant species of Bioxylus .

Figures

Figures 1–5. Dominican amber Eucnemidae. 1) Mioxylobius bicolor Otto sp. nov., dorsolateral view (distorted). 2) Mioxylobius bicolor Otto sp. nov., antenna. 3) Mioxylobius bicolor Otto sp. nov., ventrolateral view. 4) Balistica serrulata Otto sp. nov., lateral view. 5) Balistica serrulata Otto sp. nov., ventrolateral view. (Scale: 2 = 0.5 mm; 1, 3, 5 = 1.0; 4 = 2.0 mm).