Trechus lama, 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 : 55-56

Trechus lama sp. n.

( Figs. 66 , 93 )

Type material: Holotype male, with label data “ TIBET ( South Central ) 29.VI.07, Dulong, Kurum vall. NW Lhasa, 4900–5200 m, ca. 29°42’18N 90°35’16E ”, “south ascent of Tsubu side valley, above Tsurphu Monastery” ( BMNH) . Paratypes: 21 males, 7 females, with same label data as holotype ( BMNH, CKAB, CSCHM) .

Description: Body length: 3.5–4.0 mm.

Colour: Dorsal surface dark brown, shiny, with pronotum in most specimens somewhat lightened reddish brown. Antennae, palpi and legs yellowish brown; in some specimens distal half of antennal segment III or IV and antennal segments IV–XI on the whole darkened.

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

Head: Temples 4/5 – 5/6 of length of eyes, in some specimens almost as long as eyes. In all other characters agreeing with T. astrophilus sp. n.

Pronotum: Proportions: WP/LP = 1.19–1.29, WP/WPB = 1.29–1.36, WP/WH = 1.19–1.23, WE/WP = 1.69–1.79. Sides more strongly concave anterad of hind angles, the latter large, sometimes slightly bent outwards, slightly obtuse or rectangular. Base slightly curved anteriorly at outer fifth. Basal depression rugose both sides of middle of pronotum due to the presence of several small longitudinal wrinkles in addition to the convex surfaces of sculpticells. In all other characters agreeing with T. astrophilus sp. n.

Elytra: Broader oval, with proportion WE/LE = 1.50–1.55. Sides with shoulders almost evenly rounded. Striae more deeply punctate. Preapical seta is located close to the second stria and at the beginning of the posterior elytral seventh or eighth. In all other characters agreeing with T. astrophilus sp. n.

Legs: Relatively slender.

Male genitalia: Aedeagal median lobe average in length (LE/LA = 2.69–2.88), more strongly curved in basal half, slightly elongate towards apex, but with terminal lamella short; the latter distinctly curved upwards, its base slightly stepped from level of ventral margin of median lobe. Basal bulb average. Internal sac with slightly sclerotized longitudinal sheets below median lobe ostium, without distinct copulatory piece.

Etymology: The specific name refers to the Buddhist monks of Tibet, and especially to the monks of the very old Tsurphu Monastery which is located near the type locality of the new species; noun in apposition.

Identification: This new species is very similar to the above described T. astrophilus sp. n., but differs in having antennae paler, pronotal hind angles larger, basal depressions more distinctly rugose, elytra broader oval, and especially by having aedeagal internal sac only weakly sclerotized. It is also similar to T. folwarcznyi Deuve, 1997 , but has larger body size, head, antennae and legs slender, temporae longer and elytra much broader. In male genitalia characters T. lama sp. n. can easily be distinguished from both T. budhaensis sp. n. and T. yeti sp. n., which also have more slender appendages, broader oval elytra and weak internal sac sclerotisation of aedeagal median lobe, by the much stouter aedeagal median lobe with a shorter terminal lamella which is slightly stepped from the level of the ventral margin of the median lobe.

Relationships: This species is the presumed sister species of T. astrophilus sp. n., see the latter, above.

Distribution: Fig. 100 . Transhimalaya: Currently only known from the source area of a snow water brook on south western side of middle Tsubu Valley (or Tsurphu Valley) which is the north western side valley of the Kurum Valley north west of Lhasa.

Habitat: Higher alpine zone. The specimens were found under stones on gently inclined slopes of eastern exposition and close to small melt water brooks at altitudes between 5100 and 5200 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 65–80. Aedeagal median lobe with sclerotized portions of internal sac in lateral view (Figs. 65–71, 77–80; Figs. 65, 68–71, 79, 80 in addition with parameres) and in dorsal view (Figs. 72–76). Figs. 65, 74, Trechus astrophilus sp. n., paratype. Fig. 66, T. lama sp. n., paratype. Fig. 67, T. singularis sp. n., holotype. Fig. 68, T. tsampa sp. n., paratype. Figs. 69, 76, T. yak yak ssp. n., paratype. Figs. 70, 73, T. religiosus sp. n., paratype. Figs. 71, 72, T. chaklaensis sp. n., paratype. Fig. 75, T. yak shogulaensis ssp. n., paratype. Fig. 77, T. antonini sp. n., non-type specimen from Lhachen La (= locus typicus). Fig. 78, T. folwarcznyi Deuve, 1997, non-type specimen from Shogu La (= locus typicus). Fig. 79, T. rarus sp. n., holotype. Fig. 80, T. tseringi sp. n., paratype.

FIGURES 93–95. Habitus. Trechus lama sp. n., paratype, male (93). T. religiosus sp. n., paratype, male (94). T. chaklaensis sp. n., paratype, female (95).