Trechus yeti, 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 : 44-45

Trechus yeti sp. n.

( Figs. 33 , 61 , 90 )

Type material: Holotype male, with label data “ TIBET South Centr. 3–4.VII.07, NE of Shogu La pass 5000–5350 m 29°54’48– 29°57’20N 90°08’28– 90°07’49E ” ( SMNS).

Paratypes: 4 males, with same label data as holotype ( CSCHM); three of these specimens where used for further studies in molecular genetics and bear the additional label “HS 411”, “HS 412” and “HS 413”, respectively. These last mentioned three specimens each lack three legs.

Description: Body length: 3.9 mm.

Colour: Head and elytra shiny dark brown, pronotum reddish brown. Antennae, palpi and legs yellowish brown; distal portion of antennal segment III as well as antennal segments IV–XI on the whole darkened.

Microsculpture: As described in T. bhudaensis sp. n.

Head: Frontal furrows hardly flattened at level of hind suborbital seta. In all other characters agreeing with T. budhaensis sp. n.

Pronotum: Average sized, cordate, slightly transverse, strongly contracted towards base; proportions WP/ LP = 1.25–1.27, WP/WPB = 1.35–1.40, WP/WH = 1.18–1.19, WE/WP = 1.70–1.74. Surface strongly convex. Sides concave in posterior quarter. Hind angles relatively small, slightly obtuse. Marginal gutter narrow, not widened towards laterobasal depressions. Base very weakly convex in middle and more distinctly curved anteriorly at outer fifth; basal depressions smooth.

Elytra: Slightly more slender, with proportion WE/LE = 1.54–1.56. In all other characters agreeing with T. budhaensis sp. n.

Legs: Moderately slender.

Male genitalia: Aedeagal median lobe slender, average in length (LE/LA = 2.38–2.45), strongly curved basally and more elongated towards apex, in lateral view distinctly widened dorsally before apex. Basal bulb small. Terminal lamella relatively long, in lateral view evenly curved upwards. Internal sac very poorly sclerotized: In lateral view a very fine and hardly visible longitudinal sheet somewhat below the ostium. Parameres slender.

Etymology: The specific name refers to a famous but practically unexplored creature of the Himalayan- Tibetan fauna, the Yeti; noun in apposition.

Identification: Both in external and male genitalia characters very similar to the above described T. budhaensis sp. n., but differs at follows: Head and elytra darker, pronotum proportionally larger, aedeagal median lobe larger, with basal bulb proportionally smaller, with dorsal surface distinctly widened in middle of median lobe, and with internal sac sclerotisation almost completely reduced. It differs from other species of the T. antonini group primarily by the more slender legs and by the longer and more strongly curved terminal lamella of the aedeagal median lobe.

Relationships: Sister species of T. budhaensis sp. n., see chapter Relationships of the latter, above.

Distribution: Fig. 100 . Uppermost Shogu Tshu Valley of western Nyainqentanglha Shan Massif, east of Jomo Gangtse Peak.

Habitat: Higher alpine zone. The individuals of the type series were found under big stones along the rocky bank of a glacier lake at 5170 m.

Figures

FIGURE 100. Map of Southern Central Tibet showing distribution of species of the Trechus antonini group (white circles). 1, T. antonini Deuve, 1997. 2, T. religiosus sp. n. 3, T. astrophilus sp. n. 4, T. budhaensis sp. n. 5, T. rarus sp. n. 6, T. yeti sp. n. 7, T. folwarcznyi Deuve, 1997. 8, T. yak yak ssp. n. 9, T. yak shogulaensis ssp. n. 10, T. tseringi sp. n. 11, T. singularis sp. n. 12, T. tsampa sp. n. 13, T. lama sp. 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 52–64. Aedeagal median lobe with sclerotized portions of internal sac in lateral view (Figs. 52–56, 60–63; Figs. 52, 54, 55, 60, 61, 63 in addition with parameres) and in dorsal view (Figs. 57–59, 64). Fig. 52, Trechus damchungensis Deuve, 1997, holotype. Figs. 53, 57, T. cf. damchungensis Deuve, 1997, paratype from Tangula Pass. Fig. 54, T. mieheorum sp. n., paratype. Figs. 55, 58, T. bastropi sp. n., paratype. Fig. 56, T. hodeberti Deuve, 1997, nontype specimen from Lhachen La (= locus typicus). Figs. 59, 60, T. solhoeyi sp. n., paratype. Fig. 61, T. yeti sp. n., paratype. Fig. 62, T. budhaensis sp. n., paratype. Fig. 63, 64, T. rolwalingensis sp. n., paratype.

FIGURES 87–92. Habitus. Fig. 87, Trechus martinae sp. n., paratype, female. Fig. 88, T. mieheorum sp. n., holotype. Fig. 89, T. solhoeyi sp. n., paratype, male. Fig. 90, T. yeti sp. n., holotype. Fig. 91, T. astrophilus sp. n., paratype, male. Fig. 92, T. tsampa sp. n., holotype.