Arocatus pseudosericans Gao, Kondorosy & Bu 2013

Arocatus pseudosericans Gao, Kondorosy & Bu, 2013

(Figs. 20, 28–31)

Arocatus sericans (non Stål, 1859): Hidaka (1964: 288, 1965: 222) and subsequent authors. Misidentification. Arocatus pseudosericans Gao, Kondorosy & Bu, 2013: 694, 701. Holotype: ♂, China: Shaanxi, Chengguan, Foping county; NKUM (examined).

Material examined. TAIWAN. Taipei: Taihoku [= Taipei], iv., coll. T. Shiraki, identified as “ Arocatus sericans Stål ” (1 ♀, NTU); Ilan Co.: Tabo (Rato) [= Duowang], 22.viii.1923, coll. T. Shiraki (1 ♂ 1 ♀ NTU); Taichung Co.: Lishan, 1900 m, 26.vi.1979, leg. K.S. Lin & L.Y. Chou (1 ♀ TARI), Liyang, 19.ix.1981, leg. T.C. Hsu (1 ♀ NTU); Nantou Co.: Sungkang, 30.v.1965, leg. B.S. Chang (1 ♀ NMNS, 1282-33983); same locality, 2100 m, xii.1984, Malaise trap, leg. K.S. Lin & K.C. Chou (1 ♀ TARI); same locality, x.1985, Malaise trap, leg. K.S. Lin (1 ♂ TARI); Tsuifeng, 2300 m, xii.1984, Malaise trap, leg. K.S. Lin & K.C. Chou (1 ♂ TARI); Tungpu, 1200 m, 22– 25.xi.1982, leg. K.C. Chou & S.P. Huang (1 ♀ TARI); Mt. Li Ying, 25.i.2011, leg. C.T. Tang (1 ♀ NCHU); Hualien Co.: Lianhua Pond Trail, 11–13.x.2013, leg. K. Takahashi (1 ♀ NMNS); Shinbaiyan, 1644 m, 19– 20.x.2013, leg. K. Takahashi (1 ♀ NMNS); Chiayi Co.: Alishan Township, Chashan, 8.iii.2016, leg. B.S. Kuo (3 ♂♂ 2 ♀♀ NMNS); Kaohsiung Co.: Fenggangshan, 20.i.2010, leg. Y.B. Fan (1 ♀ TFRI). — SOUTH KOREA. Gyeongsangbuk-do: Gimcheon-si, Daedeok-myeon, Yeonhwa-ri, 20.ix.2012, leg. S.W. Park (1 ♀ NIBR) (Figs. 28–29).

Diagnosis. This species is recognized within the genus Arocatus by the combination of the following characters: body with long, dense pilosity (Fig. 20); head red, apex of clypeus and an extensive interocular patch black (the two sometimes connected); pronotum provided with a rather strong median carina, black, margined with red laterally and along midline in its whole length; corium black, basal portion of costal margin more or less extensively red (Figs. 28–31). Male genitalia were illustrated by Yang (2007, as sericans) and Gao et al. (2013).

Distribution. China (Fujian, Guangxi, Guizhou, Shaanxi, Sichuan, Zhejiang); Japan (Honshu, Kyushu) (Gao et al. 2013); Korea (new record); Taiwan (new record).

Remarks. Arocatus sericans (Stål, 1859) was recorded from Taiwan first by Hidaka (1964, 1965); later Yang (2007) provided a record and illustrations of male genitalia and Zheng & Lin (2013) a photo of a Taiwanese specimen. Reexamination of the voucher specimen of Yang (2007) deposited in TARI and studying the photo of Zheng & Lin (2013) left no doubt that both of these records pertain to A. pseudosericans. Several additional workers (Takara & Azuma 1972, Zheng & Zou 1981, Azuma & Kinjo 1987, Lee & Kwon 1991, Lee et al. 1993, Kwon et al. 2001, Péricart 2001, Shao et al. 2008, 2010, Nakatani & Kohno 2012, Gao et al. 2013, Ishikawa 2016) listed the species from Taiwan without referring to any exact locality, listing any examined material, or referring to any source of information; most of these records can probably be traced back to the records of Hidaka (1964, 1965). No specimen of A. sericans from Taiwan has been seen during the present study, and we consider all previous records as misidentifications pertaining to A. pseudosericans; A. sericans apparently does not occur in the country.

Probably all previous records of A. sericans from Japan and Korea also pertain to A. pseudosericans. Several

voucher specimens were seen from Korea, deposited in NIBR (Fig. 28–29); at least the illustrations of Esaki (1950:

221, fig. 566), Hidaka (1962: plate 43, fig. 6), Nakatani & Kohno (2012: plate 85, fig. 332a) and Enju et al. (2013:

263), all based on specimens from Japan, certainly pertain to A. pseudosericans.

Intraspecific variability. An examination of specimens from Taiwan and comparison with material from

China (deposited in NKUM) and Korea (deposited in NIBR) revealed that the diagnostic characters of A.

pseudosericans provided by Gao et al. (2013), based exclusively on specimens from China and Japan, need

revision, as follows:

(1) The black interocular patch on head is usually broadly separated from the marking of the clypeus in the continental populations, but it is occasionally connected with the latter one by a narrow, frequently faint median vitta.

(2) Abdominal venter uniformly red except for genital capsule (♂) and middle of ventrite VII (♀), or extensively black in middle, except for red margins (Fig. 29), or with black transverse fasciae along posterior margins of abdominal ventrites III–VII.

(3) The red markings on the midline and lateral margins of pronotum, midline of scutellum, and base of costal margin of fore wing might be more (Fig. 28) or less extensive (Fig. 30).

(4) Total body lengths of specimens of A. pseudosericans from Taiwan measured during the present study ranged as 6.0– 6.7 mm (♂♂, n = 5) and 6.5–7.4 mm (♀♀, n = 9), thus specimens are somewhat smaller in average; all females fell out of the range given by Gao et al. (2013) based on material from China and Japan: 5.90–7.00 (♂♂, n = 5) and 7.70–7.80 (♀♀, n = 2). The size difference between specimens from the Asian mainland (Korea, Figs. 28–29) and Taiwan (Figs. 30–31) is conspicuous.

In spite of the above differences, male genitalia showed no remarkable variability among material from different

places within the distribution area and they corresponded well with the illustrations provided by Gao et al. (2013:

figs. 5E–H, 6C–E), therefore we recognize all of them conspecific. Conspicuous intraspecific variability in other

species of Arocatus have been documented as well, e.g. in A. pilosulus Distant, 1879 (Gao et al. 2013), A. roeselii

(Schilling, 1829) (Péricart 1999), and A. longiceps Stål, 1872 (Stehlík & Hradil 2000, Aukema & Hermes 2009).