Medhiama schawalleri Bordoni, 2002

Zhou, Yu-Lingzi & Zhou, Hong-Zhang, 2012, Taxonomy of the genus Medhiama Bordoni, 2002 (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) with descriptions of three new species, Zootaxa 3478, pp. 169-191 : 187-189

8. Medhiama schawalleri Bordoni, 2002

( Fig. 9 A, B)

Bordoni, 2002: 673 (Type locality: Nepal, 464, Myagdi Distr., Myagdi Khola N Dobang; 2800–3100m); Bordoni, 2007b: 71 (catalog); Assing, 2010: 482 ( Nepal, Dhaulagiri Himal, Myagdi Khola valley, Italy camp).

Material examined: male, with labels as follows: “ HOLOTYPUS, Medhiama , schawalleri n. sp., Bordoni det. 1997”/ “Laboulbeniales, n. 2153, Walter Rossi”/ “ Nepal 464 Myagdi ‘Distr.,’ 1995, Myagdi Khola N Dobang, 2800–3100 m. 22.–24.V., MARTENS & SCHAWALLER” ( SMNS).

Description. Measurement. BL= 6.23 mm, FL= 3.86 mm, HL= 1.24 mm, HW= 0.91 mm, PL= 1.27 mm, PW= 0.80 mm, EL= 1.24 mm, EW= 1.18 mm.

Body nearly cylindrical and medium sized. Entirely dark brown, except legs, maxillary palpi, labial palpi and posterior half of abdominal segment IX lighter in color. Antennomere II reddish brown.

Head. Subrectangular (HL to HW ratio 1.35), tempora straight and slightly widened, posterior angles widely rounded. Dorsal integument entirely bearing mixed and distinct microsculpture composed of isodiametric microsculpture and transverse microstriae, and distributed deep and medium sized punctures, puncture intervals 1/2 puncture diameter. Median longitudinal region impunctate, width equals to 2–3 puncture diameters; frontal region wrinkled basally and entirely bearing transverse microstriae, and 3 pairs of tiny punctures. Each side of cranium with anterolateral puncture near antennal insertion, midlateral puncture not very far from dorsal margin of eye (3–4 puncture diameters to eye), temporal puncture rather near lateral margin (at lateral 1/6) and occipital puncture rather near posterior margin (at posterior 1/6). Frontal furrows deep and long, convergent backwards; anteocular furrows indistinct, scarcely observable. Eye medium sized and protruding, diameter longer than 1/4 of temporal length (eye: tempora = 0.23: 0.81 mm). Epistoma relatively wide, subrectangular and flat, with a pair of tiny punctures. Distance between antennal insertions 0.29 mm, longer than distance from antenna to eye (0.23 mm).

Antennae. Scape stout, thickened apically, much longer than three subsequent antennomeres combined, 0.48 mm; antennomere II elongate, 0.15 mm; III elongate, subequal to II; IV and V subequal in length, 0.10 mm; last antennomere of medium length, 0.24 mm, slightly longer than that of two preceding antennomeres combined.

Mouthparts. Labrum bilobed, with a median longitudinal groove. Maxillary palpus elongate, segment III longest, last segment slender, obconical and shorter than the penultimate. Labial palpus distinctly slender, last segment longest.

Neck. Medium width (0.35 mm), 1/3 of head width, with a transverse substraight ridge on anterior 1/3.

Pronotum. Subrectangular (PL to PW ratio 1.60), of same length as head but narrower. Widest at anterior 1/3, narrowest at posterior 1/3. Anterior angles widely rounded and slightly protruding, lateral margins sinuate from middle, posterior angles rounded. Integument bearing distinct transverse microstriae, and a pair of admedian row of 12–14 punctures, smaller than those on head. Areas outside admedian rows with additional, irregular, sparsely set punctures.

Mesoscutellum. Shiny, extensively bearing distinctly transverse microstriae and with a pair of tiny punctures near apex.

Elytra. Subrectangular (EL to EW ratio 1.05), of same length as pronotum but distinctly wider. Humeri well developed, lateral margins widened posteriorly, hind margin rounded. Integument shiny, without microsculpture; each side symmetrically with regular rows of punctures, interspaces between rows 1–2 puncture diameters; deflexed portion of each elytron with 3–4 rows of punctures.

Legs. First four segments stout, but not dilated in protarsi and metatarsi, whereas relatively slender in mesotarsi; each last segment as long as the II–IV combined. Protibia with apical ctenidium and subapical ctenidia, meso- and metatibia only with apical ctenidium.

Abdomen. Cylindrical, broadest at segment VII. Tergites III–VII shiny, surface entirely with basal polygonal reticulus and extensive transverse microstriae; punctures small, sparsely scattered, interspace between them 5–6 puncture diameters, but slightly denser on tergite VII. Each tergite without distinct basal impression near anterior margin. Surface between two basal transverse carinae of tergites III–VII bearing distinct polygonal reticulum. All abdominal sternites shiny, with transverse microstriae and setiferous punctures as those on tergites.

Male ( Fig. 9 A–B). Abdominal segment VIII entirely covered with setiferous punctures, posterior margins of sternite VIII protruding posteriorly. Tergite IX symmetrical, connected mediobasally. Sternite IX, with short linearshaped base and subtruncated apex. Tergite X symmetrical and oblong, broadest at anterior 1/4, anterior 1/4 gradually sharpened ( Fig. 9 B). Aedeagus subspherical and small sized ( Fig. 9 A), basal bulb 0.48 mm long. Parameres symmetrical and foot-like, 0.45 mm and slightly shorter than basal bulb length. Internal sac loudspeaker-shaped and with some rows of small spines in middle.

Distribution. Nepal.

Remarks. This species can be easily distinguished from its congeners by the following characters: substraight lateral margin of head, large head punctures, sparsely distributed abdominal punctures, sternite IX, tergite X and unique aedeagus.

Figures

FIGURE 9. Medhiama schawalleri Bordoni: A. aedeagus, dorsal view; B. male tergite X. Scale bars 0.15 mm.