Metochus uniguttatus (Thunberg, 1822)

Kondorosy, Előd, Rédei, Dávid & Mejlon, Hans, 2014, Taxonomic corrections to species of Rhyparochromidae (Hemiptera: Heteroptera) described by Carl Peter Thunberg, Zootaxa 3838 (5), pp. 567-574 : 571-573

Metochus uniguttatus (Thunberg, 1822)

( Fig. 8–13 )

Pendulinus uniguttatus Thunberg, 1822b: 6 . Syntype (s): Caput bonae spei [= South Africa: Cape of Good Hope] (in error); depository not stated.

Pendulinus guttatus Thunberg, 1825: 5 . Syntype (s): Promontorium Africes bonae spei [= South Africa: Cape of Good Hope] (in error); depository not stated. Synonymized by Stål (1867: 382). Incorrect subsequent spelling.

Rhyparochromus bengalensis Dallas, 1852: 572 . Lectotype ( Scudder 1967: 259) (♂): India, N. Bengal; BMNH. Synonymized by Stål (1874: 162); confirmed subjective synonym.

Dieuches yeh Dohrn, 1860: 160 . Syntype (s): China: Hong Kong; lost ( Péricart 2001: 200). Synonymized by Distant (1903: 82); confirmed subjective synonym.

Selected references for M. uniguttatus . Stål (1867): 382 ( Beosus , synonymy), Distant (1903): 83 (redescription, figures, records, distribution, synonymy), Breddin (1906): 321 ( Dieuches , identity, type locality, diagnostic characters), Bergroth (1915): 174 ( Metochus , identity), Hidaka (1964): 295 (records, distribution), Slater (1964): 1241 (catalogue, distribution, bibliography), Takara & Azuma (1972): 111 (records, distribution), Zheng & Zou (1981): 202 (distribution, identity, taxonomic problems), Easton (1992): 31 (record), Easton & Pun (1997): 576 (records), Péricart (2001): 200 (catalogue, distribution), Hayashi (2002): 142 (listed, distribution), Miyamoto & Yasunaga (1989): 176 (listed, distribution), Ishikawa & Tomokuni (2012): 358 (diagnosis, colour photo, distribution), Zheng & Lin (2013): 171 (redescription, colour photo of adult and larva).

Selected references for M. bengalensis . Bergroth (1915): 174 ( Metochus , identity), Slater (1964): 1240 (catalogue, distribution, bibliography), Zheng & Zou (1981): 203 (redescription, drawing, photo, distribution), Péricart (2001): 200 (catalogue, distribution).

Selected references for M. yeh . Breddin (1906): 323 (redescription, diagnostic characters), Slater (1964): 1242 ( Metochus , catalogue, distribution, bibliography), Zheng & Zou (1981): 202 (distribution, identity, taxonomic problems), Péricart (2001): 200 (catalogue, distribution).

Type material examined. Pendulinus uniguttatus . Lectotype (present designation) ♂ ( Figs. 9–13 ): “( Pendulinus ) / guttatus / Cap.” [handwritten ( Fig. 12 )]; “Stål” [handwritten ( Fig. 13 )]; “Uppsala Univ. Zool. Mus . / Thunbergsaml. nr. 17468 / Pendulinus guttatus / Cap. TYP” [red, printed]; “ LECTOTYPUS / Pendulinus uniguttatus / Thunberg, 1822 / desig. Kondorosy, 2013” [with red frame, printed]; “ NEOTYPUS / Pendulinus guttatus / Thunberg, 1825 / desig. Kondorosy, 2013” [with red frame, printed]; “ guttatus . / Cap. 4” [handwritten, pinned in the drawer next to the specimen ( Fig. 11 )]; deposited in UPSZ.

Dieuches bengalensis . Lectotype ( Scudder 1967) ♂ ( Fig. 8 ): “ Type ” [printed circular label encircled with red]; “N. / Bengal // 42. / 25.” [handwritten circle]; “151. RHYPAROCHROMUS BENGALENSIS ” [printed, cut from Walker (1872: 98)]; “LECTO- / TYPE ” [printed circular label encircled with deep lilac]; “ RHYPAROCHROMUS / BENGALENSIS / Dallas 1852 [handwritten] / G.G.E. Scudder 19 [printed] 65 [handwritten] / LECTOTYPE [printed]” [pink]; deposited in BMNH.

Discussion. The name Pendulinus uniguttatus first occurs in Thunberg’s (1822b) work on South African Hemiptera , and it is considered as proposal of a new species. The name Pendulinus guttatus occurs in a subsequent work of Thunberg (1825). Although it is possible that the description of P. guttatus was not intended to represent a newly described taxon but rather a subsequent reference on P. uniguttatus under a slightly different new name (viz., an incorrect subsequent spelling), previous authors treated P. guttatus as an available name ( Stål 1867, Slater 1964, Péricart 2001), and this opinion is accepted in the present paper too. A single male ( Figs. 9–10 ) provided with ancient labels as P. guttatus ( Figs. 11–13 ) was found in UPSZ and it is designated in the present paper as a lectotype of P. guttatus . No specimen labelled as P. uniguttatus could be located in Thunberg’s collection (UPSZ) and it is unlikely that any types are deposited in any other collection. The identity of this species has been uncertain since its original description ( Breddin 1906, Bergroth 1915, Zheng & Zou 1981), therefore we designate a neotype with the express purpose of clarifying its taxonomic status following Article 75 of ICZN (1999). As the original descriptions of P. uniguttatus and P. guttatus are nearly verbatimly identical, their type localities are the same, and the two taxa have been regarded as conspecific by all authors since their synonymy was proposed by Stål (1867), we designate the lectotype of P. guttatus ( Figs. 9–10 ) as the neotype of P. uniguttatus . As a result of this act P. guttatus will become a junior objective synonym of P. uniguttatus .

The genus Metochus Scott, 1874 contains about 16 species currently recognized as valid (two of them reduced to synonymy in the present study), all distributed in the Oriental Region (two of them occurring in the neighbouring Palaearctic parts of East Asia). Several species are of unknown identity, and a taxonomic revision is in progress by the first author of this paper.

Metochus uniguttatus is frequently cited in the literature. References published before 1961 were reviewed by Slater (1964). Breddin (1906), Bergroth (1915) and Zheng & Zou (1981) emphasised the problems about its identity; its identification is rendered even more difficult by the uncertainty of the type locality. The species has been recorded from several localities in India, the Andaman Islands, Sri Lanka, China, Burma ( Myanmar), Indochina, the Philippines, the Malay Peninsula, and the Malay Archipelago (Sumatra, Verlaten Island) in literature reviewed by Slater (1964); Easton (1992) and Easton & Pun (1997) added Macau and Hong Kong of southern China, while Zheng & Lin (2013) added Taiwan. Further, Metochus uniguttatus has also been recorded from several islands of the Ryukyu Archipelago of Japan ( Hidaka 1964, Takara & Azuma 1972, Miyamoto & Yasunaga 1989, Hayashi 2002, Ishikawa & Tomokuni 2012). It is very likely that these records pertain to several species of similar habitus, therefore all previous records are in need of verification.

Metochus bengalensis was described from North Bengal, India. Although it was synonymized with M. uniguttatus by Stål (1874) nearly all subsequent authors recognized it as a distinct species (cf. Slater 1964, Péricart 2001). It ( M. bengalensis ) was subsequently recorded from Sri Lanka, Cambodia, and southern China ( Kirby 1891, Zheng & Zou 1981, Péricart 2001). Reexamination of its lectotype ( Fig. 8 ) leaves no doubt that it is conspecific with the neotype of M. uniguttatus designated above, therefore the synonymy proposed by Stål (1874) is hereby confirmed.

Metochus yeh was described from Hong Kong. Distant (1903) synonymized it with M. uniguttatus . As the identity of the latter species was unknown Breddin (1906) tentatively recognized M. yeh as a distinct species and provided a redescription based on a male syntype. The type material was apparently subsequently lost ( Péricart 2001); it is currently not found in the Zoological Institute of the Polish Academy of Sciences in Warsaw which currently houses most of the types of Heteroptera described by A. Dohrn (T. Huflejt, pers. comm.). Most specimens of G. Breddin’s collection are deposited in the Senckenberg Deutsches Entomologisches Institut in Müncheberg, but none of us could find any syntype of this species there, nor in any of the collections visited so far. The detailed redescription of Breddin (1906) indicates that D. yeh is also conspecific with M. uniguttatus , therefore the synonymy proposed by Distant (1903) is confirmed.

Metochus uniguttatus can be recognized by the combination of the following diagnostic characters ( Figs. 8–10 ): antennal segment I uniformly black, segment IV with a pale subbasal annulus which is about 1.5 times as broad as dark base of the same segment; pronotum black with a small median light spot on anterior portion of posterior lobe; anterior outline of pale subapical patch of corium not deeply emarginate; apical portion of membrane marmorate (smoky brown with several small, irregularly distributed pale patches); ventral laterotergite of abdominal segment V with a large, yellow patch occupying most of its surface except anterior and posterior margins, that of abdominal segment VI with a much smaller, rounded patch; mid and hind tibiae uniformly dark; femora with long, dense pubescence.

Figures

FIGURES 8 – 13. Types of Rhyparochromidae species and selected relevant labels. 8, Lectotype of Rhyparochromus bengalensis Dallas, 1852; 9 – 13, lectotype of Pendulinus guttatus Thunberg, 1825 and neotype of Pendulinus uniguttatus Thunberg, 1822, with labels (11: label pinned in the drawer next to the specimen; 12 – 13: subsequent revision labels presumably by Stål). Scales in mm; labels not to scale.