Micropeneta alabaca, Schawaller & Bellersheim, 2022

Schawaller, Wolfgang & Bellersheim, Aron, 2022, Four new species and new records of Micropeneta Pic, 1921 (Coleoptera: Tenebrionidae: Gnathidiini) from the Oriental and Papuan Regions, including a checklist and an identification key, Zootaxa 5168 (4), pp. 471-478 : 472

Micropeneta alabaca sp. n.

( Figs 2 , 9 )

Type material. Holotype: ♂, Borneo, Sabah, Crocker Range, Gunung Alab , 1900 m, 6.III.2013, leg. M. Hauser et al., SMNS.

Description. Body length 5.5 mm, body shape ovate. Dorsal side, antennae and legs uniformly coloured brown without colour pattern or metallic shine, surface without distinct setation. Head with small punctures, sparser on clypeus, surface finely shagreened. Clypeal membrane not exposed. Male head at genae with a pair of broad, short, glabrous, and bifurcated processes pointing upright. Eyes small, distinctly globose. Antennae ( Fig. 2 ) 10-segmented with 4-segmented club. Pronotum widest across middle, 1.9x as wide as long, anterior angles rounded and protruding, posterior angles rectangular, lateral margins regularly rounded, broadly beaded, with fine dentation, posterior and anterior margins finely beaded; surface of pronotum dull, shagreened, with fine punctures similar to those on head, anterior part of male pronotum with broad medial impression, anterior margin without teeth; prothoracic hypomera without punctures, surface smooth and feebly shagreened; prosternal apophysis somewhat protruding backwards. Elytra ovate, surface shining, 0.9x as wide as long, widest across middle, with large punctures regularly arranged in rows, punctures distinctly larger than pronotal punctures, diminishing in posterior part of elytra, intervals with a row of fine punctures; lateral margins with fine dentation and visible in dorsal view nearly over complete length of elytra, humeral angles not pronounced; epipleura diminishing somewhat before apex, with a few scattered small punctures, punctures smaller than those on metasternum. Hind wings absent. Abdominal ventrites with fine punctures smaller than those on elytra, last visible ventrite 5 not beaded and without modifications. Legs without specific characters, anterior tibiae triangular, with external keel prolonging to the distal angle, and internally with a brush of light hairs, middle and posterior tibiae rounded in cross section and externally without any keels. Aedeagus ( Fig. 9 ) with broad triangular apicale with rounded apex.

Diagnosis. Micropeneta alabaca sp. n. can be recognised by the shape of the pair of broad, short, and bifurcated processes on the male head, by the male pronotum anteriorly with distinct impression but anterior margin without medial teeth, by the pronotum with lateral margins strongly rounded and broadly beaded, by the pronotum with shagreened surface, and by the distinct regular elytral rows of punctures. Micropeneta excavatifrons Pic, 1921 ( Fig. 3 ) has also the male pronotum anteriorly with a broad impression, but the male head armature is shorter and only tubercle-like and not bifurcated, and the pronotal disc between punctures is shining. Micropeneta mjoebergi Bremer & Ferrer, 1994 from Sarawak has a similar armature on the male head as M. alabaca sp. n., but has additionally the anterior margin of the male pronotum with a pair of distinct, narrowly situated teeth, and the pronotum is widest before middle with the anterior angles not protruding (according to figures in Bremer & Ferrer 1994). See also identification key below.

Etymology. Named after Gunung (= Mt.) Alab, in whose vicinity the holotype was collected.

Figures

FIGURES 1–8. Dorsal view of male species of Micropeneta Pic, 1921 (all in SMNS). 1. M. kinabaluca sp. n., holotype. 2. M. alabaca sp. n., holotype. 3. M. excavatifrons Pic, 1921, non-type. 4. M. papuana sp. n., holotype. 5. M. sodalis Bremer, 1997, non-type. 6. M. laotica sp. n., holotype. 7. M. leytica Schawaller, 1994, holotype. 8. M. tarandus (Kaszab, 1946), non-type. Scale bar: 3 mm.

FIGURES 9–13. Aedeagus of species of Micropeneta Pic, 1921 (all in SMNS). 9. M. alabaca sp. n., holotype. 10. M. laotica sp. n., holotype. 11. M. papuana sp. n., holotype. 12. M. sodalis Bremer, 1997, non-type. 13. M. kinabaluca sp. n., holotype. Scale bar: 1 mm.