Hydropsyche orbiculata Ulmer 1911

Ito, Tomiko & Nozaki, Takao, 2018, The family Hydropsychidae Curtis (Trichoptera) in the Ryukyu Archipelago, southwestern Japan, Zootaxa 4504 (4), pp. 545-565 : 558-560

Hydropsyche orbiculata Ulmer 1911

( Fig. 7 A–7R)

Hydropsyche orbiculata Ulmer 1911 , 397–399, figs 7, 8, male, Taiwan; Malicky and Chantaramongkol 2000, 812, 851, pl. 25, male, Taiwan.

Hydropsyche yaeyamensis Tanida 1986 , 479–482, fig. 4, male, female, larva, habitat, Ishigaki-jima; Tanida 1997, 447. New synonym.

Specimens examined. Taiwan: 2 males, Nantou, Ren’ai Xiang, Huisun Forest Area, Beigang River , 490 m a.s.l., 3.iii.2015, N. Nishimura, L. Ishigaki-jima : 8 males, 60 females, Omoto-dake , 18–19.iii.2002, I. Oshima et al ; 2 females, same locality, 26.xi.2003, M. Takai ; 1 male, same locality, 20.v.2009, K. Tojo ; 1 female, Miyara-gawa , 60 m a.s.l., 12.iv.2011, TI , P; 1 male, 1 female, same locality, 30.x.2015, TI , L; 2 females, Nagura-gawa , 8–18 m a.s.l., 11–13.iv.2011, TI , P & S; 7 females, same locality, 25–31.x.2012, TI , L, P & S; 5 females, same locality, 18– 20.iii.2016, TI , L, P & S; 1 male, 5 females, Nagura-gawa, Takeda , 12–19.x.1999, KK, L ; 1 female, Nagura-gawa, Itona , 15.x.1999, KK, L ; 2 females, Tomino , 5.vi.2003, M. Takai ; 1 female, Ara-kawa , 55 m a.sl., 28.xi.2013, TI & RS, S. Iriomote-jima : 2 males, Omija-gawa, Omija-bashi , 24.iii.1999, TI & AO, L; 1 male, same locality, 29.x.2012, TI , P.

Distribution. Japan: Ryukyu (Ishigaki-jima, Iriomote-jima). Taiwan.

Remarks. This species was originally described based on two males from Kanshirei, Taiwan ( Ulmer 1911), and recorded in many localities in Taiwan ( Hsu 1997; Malicky & Chantaramongkol 2000). However, Tanida found that the specimens from Ishigaki-jima, southern Ryukyu were slightly different from H. orbiculata in apical parts of tergite X, and considered them being a new species, i.e., H. yaeyamensis Tanida 1986 . He showed the diagnosis of H. yaeyamensis referring to the Ulmer (1911) ’s figures of H. orbiculata as follows: Apical parts of tergite X extend in parallel with squarish apices in H. yaeyamensis , but curved inwards with acute apices forming an ovoid mesal structure in H. orbiculata ( Tanida 1986) .

In 2017, we obtained figures of the holotype male (label “ Formosa, Kanshirei, V.09 Sauter, Coll. Ulmer, 6- 63”; figured by W. Mey) and a photograph of a paratype male (label “Kanshirei Formosa, 19–27.v.08, Sauter, Coll Ulmer, Eing Nr 6 63; photographed by T. Dalsgaard) of H. orbiculata Ulmer 1911 , deposited in the Zoological Museum, Hamburg University ( Figs 7 A–7D). Although we couldn’t obtain the figure or photograph of the dorsal aspect of the holotype, because it can’t be found at present time (T. Dalsgaard, personal communication, 25 November 2017), segment IX, inferior appendages and phallic apparatus of the holotype ( Figs 7A, 7B ) and apical parts of tergite X of the paratype ( Figs 7C, 7D ) are identical to those of Tanida’s male specimens collected from Ishigaki-jima ( Tanida 1986, fig. 4; Figs 7K, 7M, 7O, 7P ). Therefore, H. yaeyamensis Tanida 1986 must be a junior synonym of H. orbiculata Ulmer 1911 .

The shape of genitalia of the type specimens agrees with that of Taiwanese specimens of H. orbiculata ( Hsu 1997, fig. 53; Malicky and Chantaramongkol 2000, Tafel 25; Figs 7 E–7J).

Japanese name. Yaeyama-shima-tobikera.

Figures

FIGURE 7. Hydropsyche orbiculata Ulmer. Holotype male from Taiwan, figured by W. Mey (7A, 7B): 7A, genitalia, left lateral; 7B, left inferior appendage and phallic apparatus, ventral. Paratype male from Taiwan, photographed by T. Dalsgaard (7C, 7D): 7C = genitalia, dorsal; D = labels of paratype. Male from Taiwan, Nantou (7E–7J): 7E, genitalia, left lateral; 7F, same, dorsal; 7G, left inferior appendage, ventral; 7H, phallic apparatus, left lateral; 7I, apical part of phallic apparatus, dorsal; 7J, same, ventral. Male and female from Ishigaki-jima (7K–7R): 7K, male genitalia, left lateral; 7L, same, dorsal; 7M, left inferior appendage, ventral; 7N, phallic apparatus, left lateral; 7O, apical part of phallic apparatus, dorsal; 7P, same, ventral; 7Q, female genitalia, left lateral; 7R, same, ventral. Abbreviations: IX–X = abdominal segments IX–X.