Trechus thibetanus Jeannel, 1928

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 : 17-18

Trechus thibetanus Jeannel, 1928

( Figs. 2 , 15, 16, 19, 20 )

Catalogue: Trechus (s. str.) thibetanus Jeannel, 1928: 284 . Locus typicus: South Central Tibet, Dromo County, Duna [= Tuna] S of Bam Tso lake, altitude approximately 4400 m.

= Trechus pseudocameroni Deuve, 1996: 66 , syn. n. Locus typicus: South Central Tibet, Nakartse County [=Nagartse], Karo La W of Nakartse and Yam Tso lake, altitude approximately 5000 m.

Type material: Trechus thibetanus Jeannel, 1928 : Lectotype male, J. Schmidt designated 2008, with label data “Tuna: Tibetan plateau. 14.500ft. 11.vi.1924. Maj. R.H. Hingston. ”, “Everest Exp. Brit. Mus. 1924- 386.”, “ H.E. Andrewes Coll. B.M. 1945-97.”, “ thibetanus Jeannel R. Jeannel det.” ( BMNH). Paralectotypes 5 males, 3 females, with same label data as holotype ( BMNH).

Remarks: In the original description Jeannel (1928) has expressly designated the type locality and syntype series deposition as follows: “Types: nombreux exemplaires de Tuna, sur le plateau du Thibet, vers 4600 m. d’alt. (Brit. Mus.).” In the same paper he added more material of his T. thibetanus from further South Tibetan localities in a chapter “Chorologie”. A part of this material is conserved at BMNH and has now been examined. As a result, T. thibetanus sensu Jeannel, 1928 , has been found to be polytypic, including at least three distinct species: Material cited by Jeannel (1928) from Lamna La, Phuse La, Pangle, and from Rongshar Valley belongs to T. eutrechoides Deuve (1992) (see above). A single female specimen from Gautsa belongs to a third Trechus species but remains unidentified. Moreover, the true identity of T. thibetanus was hitherto really confused because Jeannel (1928) published a figure of male genitalia characters of a specimen from a locality other than the type locality: The figured aedeagus ( Jeannel 1928: p. 285, Fig. 1) is that of T. eutrechoides Deuve (1992) .

Trechus pseudocameroni Deuve, 1996 : Not studied. Identification is based on a male specimen determined and sent to the author by Thierry Deuve (MNHN) in February 2008 (see below), as well as on additional material from localities near the type locality.

Remarks on synonymy: The taxa T. thibetanus and T. pseudocameroni were described from two localities in South Tibet relatively close to each other (see distributional map, Fig. 98 ). In this portion of the Tibetan Himalaya between the Bam Tso and Yam Tso lakes the relief dynamic is not so striking and significant distributional barriers for alpine species seem not to occur. Anyway, on comparison of more comprehensive material from different localities within this area, no significant differences could be found between the populations, even in aedeagal characters, that indicate specific or subspecific differentiation (see Figs. 13, 14, 17, 18 ).

Additional material: CHINA: South Central Tibet : 1 male, Kambala [= Gampa La, Kampa La], 120 km S Lhasa, 4612 m, leg. A. Wrzecionko, with determinational label “ Trechus pseudocameroni m. Th. Deuve det. 2005” ( MNHN) ; 1 male, 3 females, Khampa La ( Lhoka ), 4650 m, 3.VII.1995, leg. W. Heinz ( CSCHM) ; 7 males, 3 females, Yamtso-ufer bei Nagartse [shore of Yam Tso lake near Nagartse], 4450 m, 28°58’31,9N 90°24’06,0E, 28.VII.1998, leg. O. Jäger ( CSCHM) .

Identification: See key above.

Relationships: According to synapomorphic character states of the longer copulatory pieces of the aedeagal internal sac within the T. thibetanus group T. thibetanus belongs to a terminal species group comprising T. boulbeni Deuve, 1997 as well both the below newly described species T. dongulaensis sp. n. and T. namtsoensis sp. n.

Distribution and geographical variation: Fig. 98 . Tibetan Himalaya between Sikkim and Yarlung Zhangbo valley.

Habitat: Lower alpine zone; vertical distribution approximately 4400–5000 m.

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 2–11. Pronotum. Fig. 2, Trechus thibetanus Jeannel, 1928, Lectotype. Fig. 3, T. dongulaensis sp. n., paratype, male. Fig. 4, T. namtsoensis sp. n., paratype, male. Fig. 5, T. eutrechoides eutrechoides Deuve, 1992, non-type male specimen from Lamna La. Fig. 6, T. glabratus sp. n., paratype, male. Fig. 7, T. korae sp. n., paratype, male. Fig. 8, T. yak yak ssp. n., paratype, male. Fig. 9, T. yak shogulaensis ssp. n., paratype, male. Fig. 10, T. rolwalingensis rolwalingensis ssp. n., paratype, male. Fig. 11, T. rolwalingensis daldunglana ssp. n., paratype, male.

FIGURES 12–27. Aedeagal median lobe with sclerotized portions of internal sac in lateral view (Figs. 12–18, 23–26; Figs. 14, 17, 23, 26 in addition with parameres) and in dorsal view (Fig. 27); apical portion of the longer copulatory piece (Figs. 19–22). Fig. 12, Trechus thorongiensis Schmidt, 1994, paratype, the arrow pointed to the prolongated basal portion of the shorter copulatory piece. Fig. 13, T. eutrechoides eutrechoides Deuve, 1992, non-type specimen from Rongshar Valley. Fig. 14, T. eutrechoides mondaensis Deuve, 1997, paratype. Figs. 15, 19, T. thibetanus Jeannel, 1928, holotype. Figs. 16, 20, T. thibetanus Jeannel, 1928, non-type specimen from Kampa La. Figs. 17, 21, T. dongulaensis sp. n., paratype. Figs. 18, 22, T. namtsoensis sp. n., paratype. Fig. 23, T. glabratus sp. n., paratype. Fig. 24, T. wrzecionkoi Deuve, 1996, non-type specimen from Gyama, Chungenpo Chong side valley. Fig. 25, T. korae sp. n., paratype. Figs. 26, 27, T. martinae sp. n., paratype.