Copelatus tenebrosus Régimbart, 1880

Sheth, Sayali D., Ghate, Hemant V. & Hájek, Jiří, 2018, Copelatus Erichson, 1832 from Maharashtra, India, with description of three new species and notes on other taxa of the genus (Coleoptera: Dytiscidae: Copelatinae), Zootaxa 4459 (2), pp. 235-260 : 257-259

Copelatus tenebrosus Régimbart, 1880

Copelatus tenebrosus Régimbart, 1880: 210 .

Copelatus pusillus Sharp, 1882: 580 ; synonymy by Régimbart (1899: 296).

Copelatus hisamatsui Satô, 1961: 8 ; synonymy by Satô (1983: 36).

Copelatus ceylonicus Vazirani, 1969: 402 ; new synonymy.

Copelatus assamensis Vazirani, 1970: 316 ; new synonymy.

Type localities. Copelatus assamensis : " India: Assam: Umrau near Shilong". C. ceylonicus : " Ceylon, Colombo".

Type material. Copelatus assamensis : Holotype ♂, deposited in Zoological Survey of India, Kolkata, India (not studied). Copelatus ceylonicus : Holotype ♀, deposited in Colombo National Museum, Sri Lanka (not studied).

Additional material studied. Bhutan: 1♂ 1♀, Mongar [district], Thrumshingla [ Phrumsengla ] NP, 20.– 27.vi.2010, local collector ( NMPC) . India: 1♀, Assam, Chabua , vi.1943, D.E. Hardy leg. ( GWCW) ; 1♀, Assam, Kaziranga , 75 m, 7.–9.v.1976, Wittmer & Baroni U. leg. ( GWCW) ; 5 specimens, Assam, Bhalukpong , 27°02′N, 92°35′E, 150 m, 26.v.–3.vi.2006, L. Dembický leg. ( LHCM) ; 1♀, same data, but P. Pacholátko leg. ( LHCM) ; 2♂ 4♀, Kohora (= Kaziranga vill.) at green Reed hotel, 25°35′N, 93°26′E, 160 m, 16.–19.iv.2008, M. Fikáček, H. Podskalská & P. Šípek leg. ( NMPC) ; 3 specimens, Assam-Arunachal border, Bhalukpong , 27°00.8′N, 92°39.1′E, 150 m, 1.–8.v.2012, L. Dembický leg. ( NMPC, ZMFK) ; 1♂, Darjeeling, Sonapur, Mahahandra river , 9.– 15.xi.1984, B. Bhakta leg. ( NHMB) . Nepal: 1♀, Chitwan Roy. NP, Sauraha vill., 27.35N, 84.30E, 166 m, at light, 21.–27.vii.2000, J. Schneider leg. ( NMPC) ; 1♀, same data, but D. Král leg. ( NMPC) . Sri Lanka: 1♀, Sinharaya , 4.–7.xii.1979, V. Mahler Jensen lgt., Copelatus tenebrosus Rég. , det. T.G. Vazirani 1981 ( ZMUC) ; 1♂, Hanwella , 20.xii.1979, V. Mahler Jensen lgt., Copelatus ceylonicus Vaz. , det. T.G. Vazirani 1981 ( ZMUC) ; 2♂, Inginiyagala , 14.xii.1979, V. Mahler Jensen lgt. [as C. ceylonicus ] ( ZMUC) ; 20 specimens, Colombo env., 8.xi.1980, M.A. Jäch leg. ( NHMW, GWCW) ; 1♂, Galle, Unawatuna, 30.xi.2002, M. Janalík leg. (NMPC).

Comments on classification. Vazirani (1969) described C. ceylonicus based on a single female collected in 'pond in Museum' in Colombo city. The author mentioned its similarity to C. tenebrosus and differentiated the new species by the more subparallel habitus, rufo-ferruginous coloration and by the elytral striae terminating apically at the same level. We had no possibility to see the holotype, but have studied three males identified as C. ceylonicus by Vazirani and deposited in ZMUC ( Holmen & Vazirani 1990). They are all teneral, which explains their more subparallel habitus and rufo-ferruginous coloration. Otherwise, they agree well with typical specimens of C. tenebrosus from Sri Lanka and other countries across its area of distribution; the length of the dorsal elytral striae is variable even within specimens in one population and it is not usable for species delimitation.

Copelatus assamensis was described based on a single male specimen. It was compared with C. andamanicus (= C. oblitus ) and C. malaisei Guignot, 1954 , but actually it was keyed with C. tenebrosus and C. ceylonicus with only one difference mentioned: dorsal elytral striae equally abridged apically (i.e. terminated at the same level). As mentioned above, the length of the elytral striae is variable, and moreover the same character was also mentioned in description of C. ceylonicus . We had no possibility to study the holotype, however all characters mentioned in the original description, especially the testaceous surface of the pronotum and the elytra, body size 4.9 mm and sketchy drawing of median lobe fits with extensive material of C. tenebrosus from Assam and neighbouring areas in our hands. Therefore, we have no doubts about its identity and establish the following new synonymies: Copelatus tenebrosus Régimbart, 1880 = Copelatus ceylonicus Vazirani, 1969 syn. nov. = Copelatus assamensis Vazirani, 1970 syn. nov.

Distribution. Copelatus tenebrosus is one of the most widespread Copelatus species. It occurs in the entire Oriental region, in southern China and Japan in the Palaearctic region, and also reaches Australia. Here, we present the first country records from Bhutan and Nepal.