Trechus eremita, Schmidt, 2009

Schmidt, Joachim, 2009, Taxonomic and biogeographical review of the genus Trechus Clairville, 1806, from the Tibetan Himalaya and the southern central Tibetan Plateau (Coleoptera: Carabidae: Trechini) 2178, Zootaxa 2178 (1), pp. 1-72 : 28-29

Trechus eremita sp. n.

( Figs. 29 , 45, 46 )

Type material: Holotype male, with label data “ NEPAL oc. Karnali Prov., 34 km NE Jumla, Bachtal SE Taka, 29°30’12’’N, 82°24’20’’E, 3800 m, 01.VII.1999 leg. A. Weigel ” ( NME).

Paratypes: 1 male, 2 females, with same label data as holotype ( CSCHM, CWG) .

Description: Body length: 3.1–3.4 mm.

Colour: Dorsal surface brown, moderately shiny, head distinctly darker than pronotum, palpi, three or four basal antennal segments and legs yellowish brown.

Microsculpture: Head with slightly engraved slightly transverse meshes on disc, and with deeply engraved almost isodiametric meshes in frontal furrows and on neck; pronotum with faintly engraved slightly transverse meshes on disc but with deeply engraved meshes throughout basal depressions. Elytra with moderately engraved slightly transverse meshes in both sexes.

Head: As described in T. muguensis sp. n.

Pronotum: Proportions: WP/LP = 1.18–1.26, WP/WPB = 1.35–1.43, WP/WH = 1.23–1.24, WE/WP = 1.58–1.65. In all other pronotal characters agreeing with T. muguensis sp. n.

Elytra: Proportion WE/LE = 1.42–1.52. Striae impunctate, two or three inner stria slightly stretched on elytral disc, absent at base and flattened on apex; fourth stria only suggested as a fine incomplete line, outer striae completely reduced. In all other elytral characters completely agreeing with T. muguensis sp. n.

Male genitalia: Aedeagal median lobe elongate (LE/LA = 1.63–1.65), in lateral view strongly curved behind basal bulb, almost straight in the middle portion, distinctly bent upwards at the beginning of distal quarter, with undulate curve at apex; ventral side slightly widened in middle. In dorsal view, right side of median lobe slightly widened at the beginning of distal quarter; tip of terminal lamella produced, rounded. Internal sac with sclerotized portion relatively small, strongly flattened in lateral view.

Etymology: The specific epithet is used as a noun in apposition, and refers to the Latinized Greek word ‘eremita’, a hermit.

Identification: In external characters almost identical to T. franzianus Mateu & Deuve, 1979 and the forgoing described T. muguensis sp. n., but elytral micromeshes in females not so deeply engraved. In addition, T. eremita sp. n. differs from both these species by its aedeagal characters: The median lobe is more elongated than in T. muguensis sp. n., with its basal bulb not so strongly bent downwards, but with its apical portion more distinctly curved upwards. In dorsal view, the median lobe is more slender than that of T. franzianus , and not widened behind middle on its left side. For differentiation with the newly described species T. aedeagalis sp. n. and T. sculptipennis sp. n. see diagnosis of the latter below.

Relationships: See remarks in chapter Relationships of T. tilitshoensis Schmidt, 1994 .

Distribution: Fig. 98 . North slope of Sisne Himal, Western Nepal Himalaya . Up to now only known from the southern side valley of Mugu Karnali River South East of Taka.

Habitat: The few specimens of the type series were found under big stones on subalpine meadows beside a brook at an altitude of 3800 m. However, the vertical distribution of the species truly extends to the alpine zone.

Figures

FIGURE 98. Map of central parts of Tibet and the Himalaya showing distribution of species of the Trechus thibetanus group (white circles), of the Trechus pumoensis group (white squares), of the Trechus rolwalingense group (black circles), and of the Trechus stratiotes group (black squares). 1, T. namtsoensis sp. n. 2, T. dongulaensis sp. n. 3, T. thibetanus Jeannel, 1928. 4, T. glabratus sp. n. 5, T. thorongiensis Schmidt, 1994. 6, T. eutrechoides eutrechoides Deuve, 1992. 7, T. eutrechoides mondaensis Deuve, 1997. 8, T. pumoensis Deuve, 1997. 9, T. tilitshoensis Schmidt, 1994. 10, T. franzianus Mateu & Deuve, 1979. 11, T. muguensis sp. n. 12, T. eremita sp. n. 13, T. aedeagalis sp. n. 14, T. sculptipennis sp. n. 15, T. rolwalingense rolwalingense ssp. n. 16, T. rolwalingense daldunglana ssp. n. 17, T. stratiotes stratiotes ssp. n. 18, T. stratiotes malikasthana ssp. n.

FIGURES 28–35. Head, pronotum. Fig. 28, Trechus pumoensis Deuve, 1997, paratype, male. Fig. 29, T. eremita sp. n., paratype, female. Fig. 30, T. tilitshoensis Schmidt, 1994, paratype, male. Fig. 31, T. aedeagalis sp. n., paratype, male. Fig. 32, T. antonini Deuve, 1997, non-type female specimen from Lhachen La. Fig. 33, T. yeti sp. n., paratype, male. Fig. 34, T. cf. damchungensis Deuve, 1997, paratype, male from Tangula Pass. Fig. 35, T. hodeberti Deuve, 1997, non-type female specimen from Lhachen La.

FIGURES 39–51. Aedeagal median lobe with sclerotized portions of internal sac in lateral view (Figs. 39, 40, 42, 43, 45, 47, 49; Figs. 39, 40, 47, 49 in addition with parameres) and in dorsal view (Figs. 41, 44, 46, 48, 50). Fig. 39, Trechus pumoensis Deuve, 1997, paratype. Figs. 40, 41, T. franzianus Mateu & Deuve, 1979, non-type specimen from Dhauli Lake. Fig. 42, T. tilitshoensis Schmidt, 1994, non-type specimen from Gungdang N-slope. Fig. 43, 44, T. muguensis sp. n., paratype (43) and holotype (44). Figs. 45, 46, T. eremita sp. n., paratype. Figs. 47, 48, T. sculptipennis sp. n., paratype. Figs. 49, 50, T. aedeagalis sp. n., paratype. Fig. 51, T. stratiotes sp. n., paratype.