Tridensius brunneus (Franz) Jałoszyński, 2020

Jałoszyński, Paweł, 2020, Corrections to the classification of the Neotropical ant-like stone beetles misplaced in Euconnus Thomson (Coleoptera, Staphylinidae, Scydmaeninae). Part 1., Zootaxa 4755 (2), pp. 251-270 : 253-255

Tridensius brunneus (Franz) , comb. n.

Euconnus brunneus Franz, 1988: 75 .

( Figs 1–11 )

Type material. Holotype: VENEZUELA (Mérida State): ♂, three historical labels ( Fig. 2 ): “Bosque de la Car- bonera / 2000 m, Umg. Merida / Venezuela, lg. Franz” [white, printed], “ Euconnus / brunneus m. / det. H.Franz ” [white, handwritten and printed], “ Holotypus ” [red, handwritten]; during the present study a new label was added: “ TRIDENSIUS / brunneus ( Franz, 1988) / det. P. Jałoszyński, 2020” [white, printed] ( NHMW).

Diagnosis. As for genus.

Redescription. Body of male ( Fig. 1 ) stout, moderately strongly convex, brown, setae and bristles slightly lighter than cuticle; BL 1.13 mm.

Head ( Fig. 3 ) broadest at large, strongly convex eyes, HL 0.15 mm, HW 0.23 mm; frons and vertex confluent on sides, median part of head between posterior halves of eyes with tubercle composed of broadly separated flattened lateral structures connected by elevation, which is anteriorly demarcated by angulate step-wise ridge; frons between large supra-antennal tubercles slightly impressed; tempora about as long as half length of eye in dorsal view, strongly convergent posteromesad and rounded. Vertex and frons virtually impunctate; setae short and suberect, unevenly distributed: on median anterior and anterodorsal region of frons, along anterior half of mesal margin of each eye, at sides of median tubercle, along posterior margin of vertex, on tempora and geneae/postgenae. Antennae ( Fig. 1 ) slender, AnL 0.63 mm; antennomeres I and II each strongly elongate, III–X each about as long as broad or indistinctly transverse; XI much shorter than IX and X combined, about 1.4 × as long as broad.

Pronotum ( Fig. 3 ) broadest near middle; PL 0.33 mm, PW 0.28 mm. Anterior margin rounded; sides in anterior half rounded, in posterior half weakly concave, so that pronotum at base is nearly equally broad as near middle; posterior margin distinctly bisinuate; antebasal pits small, inner pair (connected by groove) indiscernible under stereomicroscope, transverse groove diffuse, slightly convex anteriorly. Punctures on pronotal disc fine, inconspicuous; setae on dorsal region short, sparse, suberect, on sides replaced by long erect bristles.

Elytra ( Fig. 1 ) together oval, broadest near middle; EL 0.65 mm, EW 0.50 mm, EI 1.30; basal impressions short and shallow, humeral calli distinct, elongate, elytral apices separately rounded. Punctures and setae similar to those on median region of pronotal disc.

Hind wings long, functional.

Legs long and slender; unmodified.

Aedeagus ( Figs 10–11 ) in the only available specimen with exserted endophallus; AeL 0.28 mm. Median lobe strongly elongate and strongly curved in lateral view; ventral diaphragm large and oval, sub-median; endophallus with complicated darkly sclerotized structures; parameres slender, short, strongly curved, each with one long apical seta.

Female. Unknown.

Distribution. Western Venezuela.

Figures

FIGURES 1–3. Tridensius brunneus (Franz) comb. n., holotype male. Dorsal habitus (1); original set of labels (2); head, prothorax and elytral base in dorsal view (3). Abbreviations: abg, antebasal groove; abp, antebasal pit; bef, basal elytral fovea.

FIGURES 4–7. Tridensius brunneus (Franz) comb. n., holotype male. Median region of vertex in dorsal view (4); head and prothorax in ventral view (5); prothorax in ventral view (6); pterothorax in ventral view (7). Abbreviations: bst, basisternal part of prosternum; gp, gular plate; hr, hypostomal ridge; hyr, hypomeral ridge; mn, mentum; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; mxp1–4, maxillary palpomere I–IV; nss, notosternal suture; psp, prosternal process; smn, submentum.

FIGURES 8–11. Tridensius brunneus (Franz) comb. n., holotype male. Intermesocoxal region of mesoventrite in ventral view (8); mesothorax in ventral view (9); aedeagus in ventral (10) and lateral (11) views.Abbreviations: dlf, dorsolateral fovea; msvp, mesoventral intercoxal process.