Laccoporus nigritulus (Gschwendtner, 1936)

Zhao, Shuang, Jia, Fenglong & Balke, Michael, 2011, Rhantus fengi sp. n. from Xizang, China, and notes on Laccoporus nigritulus (Gschwendtner) (Coleoptera, Dytiscidae), ZooKeys 94, pp. 61-71 : 65-67

Laccoporus nigritulus (Gschwendtner, 1936) Figs 10-15

Laccophilus apicicornis var. nigritulus Gschwendtner 1936: 367.

Laccoporus nigritulus (Gschwendtner): Vazirani 1970: 563-564 (new combination, new status); Nilsson 2001: 253.

Laccoporus viator Balfour-Browne 1939: 104; Nilsson 2001: 253; new synonymy.

Laccophilus sp.: Nilsson 1995: 71.

Type localities:

Laccophilus apicicornis var. nigritulus: China: Tibet, Te-ring Gompa; Laccoporus viator : China: Tibet, Gyangtse.

Type material:

Laccophilus apicicornis var. nigritulus: 10 syntypes, Te-ring Gompa. 14,000 ft. Tibet (F.H. Stewart) in ZSIC [not studied]. Nilsson (2001) mentioned a lectotype designation by Vazirani (1970), but Vazirani mentioned that he studied the holotype and one paratype, the type status is therefore rather unclear and we could not access types from ZSIC to clarify the situation.

Laccoporus viator : Holotype, „allotype” and 10 other paratypes in BMNH. We studied 2 ♂♂ paratypes labelled: „Co-type”, "Gyangtse. / 13,000 ft. / June 1904. / Tibet Expedit. / H.J. Walton. / 1903 –172.”, "Laccoporus / viator. B-B. / Co-type.".

Other material examined:

20 exs (SYSU): 2 ♂♂CHINA: Xizang, Dingri (Tering), 4300 m, 2.vi.1974, leg. Xuezhong Zhang, Academia Sinica; 1 ♀ the same data as male; 1 ♀ Xizang, suburb of Rikaze, 3826 m, 20-23.vii.1986, leg. Geqiu Liang; 5 ♂♂, 3 ♀♀ Xizang, Rikaze, 3862 m, 4.viii.1986, leg. Geqiu Liang; 1 ♂ the same data as the former, with a label "Laccophilus indicus?"; 4 ♂♂, 3 ♀♀ Xizang, Mozhugongka County, 7.viii.1986, leg. Geqiu Liang; 8 exs (MTD, NMPC, CHF) "Tibet, Yamtso-ufer bei / Nagartze, N28°58'31,9 / E90°24'6,0; 4450mNN; / 29.VII. 1998; leg. O. Jäger”, "Laccoporus nigritulus / (Gschwendtner) / Fery det. 1999"; 11 exs (MTD, CHF) "Tibet, Tingriebene / N28°34'39,7/E86°36'52,7; 4400 m / 3.-5.VIII. 1998, lg. Jäger“, "Laccoporus nigritulus / (Gschwendtner) / Fery det. 1999".

Redescription.

Measurements. Length 4.5-5.0 mm, width 2.5-2.6 mm (paratypes of Laccoporus viator : length 4.5-4.8 mm, width 2.3-2.6 mm).

Colouration

(Figs 10, 11, 15). Dorsum uniformly yellow brown. Head yellowish brown, with one short dark brown line near antennae. Antenna with antennomeres 1-4 and base of antennomeres 5-6 yellow brown, antennomeres 7-11 andapical parts of antennomeres 5-6 dark brown. Maxillary palpomeres yellow brown, apical palpomere apically dark. Labial palpomeres yellow brown, apical palpomere dark. Pronotum sometimes paler with darker median, anterior and posterior transverse bands. Elytra clearly darker than pronotum, but with the same color at base as pronotum. Ventral surface of head and thorax black. Abdomen black, ventrites 3-6 yellow brown along posterior margins (e.g. Fig. 15). Legs yellow brown with coxae black, posterior half of metacoxal process yellowstructures(see http://www.species-id.net/wiki/Laccoporus_nigritulus for high resolution images of surfaces). Head with surface sculpture consisting of small irregular polygonal meshes, with some sparse coarse and shallow punctures in posterior half. Meshes somewhat stronger on posterior portion. Clypeus with transverse series of large punctures present anteriorly. Labrum with very deep excavation, surface with short transverse meshes, anterior notch with dense and short white setae. Antenna filiform, not dilated. Pronotum more or less depressed laterally, without lateral bead, with small irregular polygonal meshes, sometimes very tiny punctures detectable. Posterior corner almost rectangular. Elytra with base as wide as posterior portion of pronotum, surface with irregular polygonal meshes in size and shape, sculpture more or less stronger than that on pronotum, tiny punctures very sparse and clearly detectable. Prosternal process thin and long,bisinuate in lateral view, almost reaching posterior margin of mesocoxae. Metaventrite medially with some coarse and strong punctures behind mesocoxae. Metacoxae and metasternum strongly and irregularly scratched, with dense longitudinal sculptures and sparse tiny punctures. Pro- and mesofemora with tuft of long setae at basal portion posteriorly. Metafemora with fine and dense sculpture and tiny punctures. Metatibia with inner spur longer than outer one. Pro- and mesotarsi smooth. Metatarsi smooth, with fine sculpture dorsally. First tarsomere of metatarsi almost as long as following two tarsomeres combined. Claws normally curved, protarsal claws longer than metatarsal claws. Metatarsomere 1 almost as long as metatarsomeres 2-3 combined. Claws regularly curved, proclaws longer than metaclaws.

Male.

Protarsus not dilated. Median lobe and parameres as in Figs 12-14.

Distribution.

China: Xizang.

Remarks.

Genus Laccoporus was erected by Balfour-Browne (1939) with Laccoporus viator Balfour-Browne, 1939 as the type species. This author had no knowledge about Laccophilus apicornis var. nigritulus Gschwendtner, 1936. The latter taxon was transferred to Laccoporus and raised to species status by Vazirani (1970) who studied two syntypes housed in ZSIC. Vazirani (1970) had doubts that Laccoporus viator and Laccoporus nigritulus were different species, but he could not study Balfour-Browne’s types. We have no access to specimens in ZSIC, but Vazirani (1970) provided an illustration of the ventral side of the median lobe of Laccoporus nigritulus , which agrees with our specimens.

The types of Laccoporus viator are from Gyangtse (Jiangzi). The types of Laccoporus nigritulus were collected from “Te-ring” (Dingri) and “Gompa” (Gangba). The distance between these sites is only about 100-120 km (Fig. 16). The two latter sites are not far (about 90-120 km respectively) from Rikaze where some of our newly studied specimens originate from. The altiude of these three sites is 3900-4300 m.

Zeng (1989) described " Laccophilus thibetanus sp. n." from Rikaze, Xizang in her PhD thesis (unpublished, in Chinese) (in the corrected thesis version, the name was changed to Laccoporus xizangensis sp. n. by herself, possibly acknowledging that Xizang is a more precise reference to the type locality than “Tibet”). Nilsson (1995: 71) recorded a " Laccophilus sp." and stated that it is based on " Laccophilus tibetanus Zeng, 1989: 4 (nom. nud., Tibet)". We found the specimens that have the same locality data as recorded by Zeng (1989) in SYSU. Although there is no specific name and no type designation attached to these specimens, we are confident that Zeng (1989) based her unpublished Laccophilus xizangensis on these specimens. All the specimens are conspecific with Laccoporus nigritulus .