Cephennomicrus politus (Scott)

Jałoszyński, Paweł, 2019, Review of Cephennomicrus and Pomphopsilla of the Seychelles (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4568 (2), pp. 357-371 : 364-366

Cephennomicrus politus (Scott)

( Figs 5 , 11 , 22–23, 34–35, 42)

Neseuthia polita Scott, 1922: 206 , pl. 19, fig. 6, 6a.

Cephennomicrus politus (Scott) ; Jałoszyński, 2008: 34.

Type material. Holotype (labels in Fig. 42 ): ♂, originally mounted on cardboard bearing male symbol and number 29(B) handwritten in black ink, now re-mounted on modern mounting card, with seven labels: " Percy Sladen / Trust Exped. / Brit.Mus. / 1926-246" [white, printed], " Silhouette, 1908 / Seychelles Exp." [white, printed], " Neseuthia / polita / TYPE. H.Scott / TYPE " [white, handwritten, with " TYPE " printed on a blue card and glued onto the white label], " politus Scott / Cl. Besuchet / dét. X 1957 " [white, printed and handwritten], "Figured specimen" [red, printed], "Type" [white circle with red margin, printed], and " CEPHENNOMICRUS / politus / ( Scott, 1922) / det. P. JAŁOSZYŃSKI, 2019" [white, printed] ( NHM).

Revised diagnosis. BL ~ 0.80 mm; frontal impression in male shallow and diffuse, impunctate and asetose, flanked by a pair of carinate elevations, vertex lacking impressions; aedeagus with slender ventral apical plate and rounded apex, flagellum in ventral view with one proximal loop.

Redescription. Body of male ( Fig. 5 ) moderately stout, strongly convex, umber brown; setae on head, pronotum and elytra very short and poorly visible. BL 0.83 mm.

Head ( Fig. 11 ) broadest at large, strongly convex and coarsely faceted eyes, HL 0.10 mm, HW 0.23 mm; frons with shallow and diffuse impression lacking punctures and setae, and flanked by a pair of short oblique carinae; frons with a pair of small tubercles with a porous field on each, vertex confluent with frons, lacking impressions; supraantennal tubercles weakly elevated. Punctures on sides of frons and vertex and on posterior portion of vertex indistinct, moderately dense, very small; setae on sides of frons and vertex and along posterior margin of vertex sparse, short and recumbent. Antennae slender, with indistinctly delimited trimerous club, AnL 0.35 mm, antennomeres I–II strongly elongate, III–X each about as long as broad, XI about as long as IX–X combined, about 1.8 × as long as broad.

FIGURES 14–25. Aedeagus in ventral (14, 16, 18, 20, 22, 24) and lateral (15, 17, 19, 21, 23, 25) views. Cephennomicrus cordithorax (14‾15), C. cornutus (16‾17), C. minor (18‾19), C. perexiguus (20‾21), C. politus (22‾23), and C. typicus (24‾25).

Pronotum subtrapezoidal, broadest near anterior fourth; PL 0.25 mm, PW 0.30 mm; anterior and posterior margins weakly convex, sides rounded in anterior third and barely noticeably sinuate in posterior third; anterior corners broadly rounded, posterior corners strongly obtuse-angled and blunt; base with two lateral pairs of small but distinct pits, inner pair connected by a shallow transverse groove, additionally with small but distinct median pit; lateral pronotal carinae not serrate. Punctures on pronotal disc very fine, inconspicuous; setae extremely short, moderately dense, recumbent, barely discernible.

Elytra oval, broadest near anterior third; EL 0.48 mm, EW 0.38 mm, EI 1.27; humeral calli distinct; apices separately rounded, subtriangular adscutellar area strongly and abruptly elevated. Punctures on elytra similar to those on pronotum, inconspicuous, surface of elytra glossy, not shagreened; setae extremely short, moderately dense, recumbent, barely discernible.

Legs moderately long and slender, unmodified.

Aedeagus (Figs 22–24) stout; AeL 0.18 mm; median lobe in ventral view with subtriangular, strongly elongate apical plate; flagellum (Figs 34–35) in ventral view with proximal loop; apical and subapical parameral setae equally thin.

Female. Unknown.

Distribution. Seychelles, Silhouette Island.

Remarks. This species was described on the basis of only one specimen ( Scott 1922). Cephennomicrus politus can be easily identified by its indistinctly delimited, glabrous frontal impression flanked by short oblique carinae, and the vertex lacking impressions. The male is also more glossy than all remaining members of this group, with the elytra not shagreened, and setae on pronotum and elytra indiscernible under magnification 80 ×.

Figures

FIGURES 1–7. Habitus of Cephennomicrus cordithorax (1), C. cornutus (2), C. minor (3), C. perexiguus (4), C. politus (5), C. typicus (6), and Pomphopsilla crenata (7).

FIGURES 8–13. Head of males in dorsal (8‾12) and anterodorsal (13) views. Cephennomicrus cordithorax (8), C. cornutus (9), C. minor (10), C. politus (11), and C. typicus (12‾13).

FIGURES 38–44. Historical (Scott's and Besuchet's) set of labels of holotypes (38, 39, 42) and lectotypes (40, 41, 43, 44). Neseuthia cordithorax (38), N. cornuta (39), N. minor (40), N. perexigua (41), N. polita (42), N. typica (43), and N. crenata (44).