Stenichnoteras montanum Scott

Jałoszyński, Paweł, 2014, The enigmatic genus Stenichnoteras Scott from the Seychelles (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 3811 (2), pp. 280-288 : 286-287

Stenichnoteras montanum Scott

( Figs. 1–14 )

Stenichnoteras montanum Scott, 1922: 217 , Plate 20, Figs. 14, 14 a, b.

Type material. Lectotype (here designated). SEYCHELLES: ♀, six labels ( Fig. 7 ): " Mahe, '08-9 / Seychelles Exp." [white, printed], "Percy Sladen / Trust Exped. / Brit. Mus. / 1926-246." [white, printed], " Stenichnoteras / montanum / TYPE H. Scott / TYPE' [white, handwritten, " TYPE " printed on blue card glued onto the label], "Figured specimen" [orange, printed], " Type " [circular, white with red margin, printed], " STENICHNOTERAS / montanum Scott, 1922 / LECTOTYPUS / P. Jałoszyński, 2014" [white, printed] (NHM). Paralectotype: 1 ♀, originally mounted on a thick card with handwritten "43", during the present study remounted and the original card pinned under the specimen, three labels: " Mahe, '08-9 / Seychelles Exp." [white, printed], " Stenichnoteras / montanum / H. Scott / Paratype " [white, printed], " STENICHNOTERAS / montanum Scott, 1922 / PARALECTOTYPUS / P. Jałoszyński, 2014" [white, printed] ( CUMZ).

Revised diagnosis. The only species of Stenichnmoteras can be identified on the basis of the generic diagnosis. The vertex with distinct lateral edges and the flat, laterally expanded subtrapezoidal pronotum with sharp lateral edges are unambiguous key characters.

Redescription. Body of female ( Figs. 1–2 ) elongate, with flattened head and pronotum but with strongly convex elytra, reddish-brown, covered with yellowish vestiture; BL 2.10–2.15 mm.

Head ( Figs. 4–5 , 8–9 ) broadest at eyes, HL 0.53 mm, HW 0.50 mm; tempora in dorsal view long and confluent with posterior margin of vertex, just behind eyes distinctly divergent posteriorly; vertex flattened, with distinct lateral and posterior edges, broader than long; frons flattened, posteriorly confluent with vertex, anteriorly steeply and abruptly lowering toward clypeus; supraantennal tubercles feebly marked. Eyes in lateral view oval, in dorsal view strongly protuberant, strongly protruding from head silhouette, lightly pigmented. Punctures on frons and vertex inconspicuous, fine; setae distributed only on posterior portion of vertex and on frons, sparse, long and suberect to erect; genae (bulging beneath eyes) and tempora covered with dense and long bristles directed posteriorly. Antennae ( Figs. 1–2 ) slender, AnL 1.25 mm; antennomeres I–VII each strongly elongate, VIII about as long as broad, IX–X transverse, XI as long as IX–X together, much broader than X, about 1.8x as long as broad, with blunt apex.

Pronotum ( Figs. 6 , 10 ) distinctly transverse, large in relation to elytra, approximately cordiform, broadest in anterior third; PL 0.55 mm, PW 0.68–0.70 mm. Anterior margin slightly concave and short; anterior corners strongly obtuse and blunt; lateral margins just behind anterior corners rapidly expanding laterally and in anterior third forming a large and broadly rounded expansion, in posterior third lateral margins slightly concave; posterior corners broadly rounded, strongly obtuse; posterior margin weakly arcuate. Pronotum with two pairs of antebasal pits not connected by groove, lateral pits adjacent to long sublateral carinae, median portion of pronotal disc in lectotype with two distinct longitudinal grooves, narrow area between them convex, in paralectotype grooves absent but there is an indistinct trace of longitudinal wrinkle. Median part of pronotum asetose and with fine inconspicuous punctures similar to those on vertex and frons, lateral expansions (laterally to sublateral carinae) ( Fig. 6 ) with moderately dense and long bristles inserted on large granules, so that cuticle appears coarse.

Elytra ( Figs. 1–2 ) strongly convex, oval, broadest distinctly behind middle; EL 1.03–1.08 mm, EW 0.83–0.88 mm, EI 1.17–1.30; humeral calli and basal impressions absent; punctures more distinct than those on pronotum, small but sharply marked and separated by spaces subequal to 2 diameters of puncture, setae sparse, long and erect. Hind wings absent.

Legs ( Fig. 2 ) long and slender.

Abdomen ( Fig. 14 ) with broad and narrow cavity under posterior margin of sternite III, with large metacoxal rests, sutures between sternites VII and VIII indistinct; sternites III-VI with thick bristles, on first three visible sternites assembled in bunches and rosettes, sternites VII and VIII only with thin and long setae.

Spermatheca ( Fig. 12 ) darkly sclerotized, small and spherical, located deeply in metathorax.

Male. Unknown.

Distribution. Mahé Island, the Seychelles.

Remarks. The type series of Stenichnoteras montanum consists of two females, one labeled as " type ", the other as " paratype ". Scott (1922) clearly mentioned two specimens, but did not use the word " type " in reference to any of them, and therefore the specimens are syntypes. In order to provide a name-bearing type for Stenichnoteras montanum , the previously illustrated specimen is here designated as lectotype.

The type specimens were collected on 29.x and 15.xi.1908, "probably they were from damp, decaying leaves on the ground" ( Scott 1922). The females differ in the sculpture of the pronotum, the one designated here as lectotype has distinct submedian grooves, while the one that becomes paralectotype has only an indistinct trace of median wrinkle. Other characters, including measurements, are similar. However, the two specimens were collected separately ( Scott 1922) and a larger sample is necessary to verify whether they show an interindividual variability or perhaps more than one species of Stenichnoteras occurs in this area.

Figures

FIGURES 1 – 3. Stenichnoteras montanum Scott, female lectotype. Total habitus in lateral (1; arrow indicates position of dorsolateral fovea) and dorsal (2) view, and ventral view of head and thorax (3).

FIGURES 4 – 7. Stenichnoteras montanum Scott, female lectotype. Head in dorsal (4) and anterodorsal (5) view, pronotum in dorsal view (6) and set of original labels (7).

FIGURES 8 – 11. Stenichnoteras montanum Scott, female lectotype. Head in anterodorsal (8) and ventral (9) view, prothorax in dorsal (10) and ventral (11) view. Abbreviations: bst, basisternal part of prosternum; bst, basistipes; cd, cardo; cl, clypeus; ep, external antebasal pit; fcg, frontoclypeal groove; fr, frons; gal, galea; gen, gena; gp, gular plate; gs, gular suture; hr, hypostomal ridge; hy, hypomeron; hyr, hypomeral ridge; ip, internal antebasal pit; lac, lacinia; lbr, labrum; lp, labial palpus; md, mandible; mn, mentum; mst, mediostipes; mxp, maxillary palpus; nr, ' neck' region'; nss, pronotosternal suture; occ, occipital constriction; pcc, procoxal cavity; pcs, procoxal socket; pf, profurca; pmn, prementum; ppf, palpifer; ptp, posterior tentorial pit; sat, subapical tooth; slc, sublateral carina; smg, submedian groove; smn, submentum; tm, temple; vt, vertex.

FIGURES 12 – 14. Stenichnoteras montanum Scott, female lectotype. Pterothorax in ventral view (12), outline of ventral portion of pterothorax in lateral view (13) and abdomen in ventral view (14). Abbreviations: aest 3, metanepisternum; ar, anterior ridge; dlf, dorsolateral fovea; lmfa, lateral metafurcal arm; mcp, mesocoxal projection; mscc, mesocoxal cavity; msvp, mesoventral process; mtcr, metacoxal rest; mtvp, metaventral process; pcr, procoxal rest; pre, prepectus; s 3 – 8, abdominal sternite III – VIII; sp, spermatheca; v 3, metaventrite; vlf, ventrolateral fovea.