Hydroptila chinensis Xue & Yang, 1990

Ito, Tomiko, Ohkawa, Ayuko & Hattori, Toshio, 2011, The genus Hydroptila Dalman (Trichoptera, Hydroptilidae) in Japan, Zootaxa 2801, pp. 1-26 : 5-7

Hydroptila chinensis Xue & Yang, 1990

( Figs. 3 , 14 B)

Hydroptila chinensis Xue & Yang, 1990 , 126–127, 15–16, fig. 4, male, female, China; Arefina et al., 2002, 97–98, figs 1–5, male, female, Russian Far East (continental parts), Japan (Honshu).

Adult. Wings dark brown with several small lighter markings. Antennae brown to light brown with darker markings at about half length and at apices.

Male. Lengths of forewing, hindwing and body 2.2–2.9 mm, 1.8–2.6 mm and 2.5–3.1 mm, respectively (n=5). Antennae 29–32-segmented; length 1.2–1.5 mm (n=5). Ventral process of sternite VII short, subacute apically. Segment IX with rounded antero-lateral apodemes. Dorsal plate almost completely membranous, thin and elongate in lateral view, in dorsal view rectangular with divergent postero-lateral angles. Subgenital plate elongate, 1.5 times length of dorsal plate; thin, triangular with strongly sclerotized lateral margins, membranous medially in dorsal and ventral views; in lateral view directed posteriad for basal 3/4 and then curved ventrad for apical 1/4. Phallic apparatus almost straight, with long narrow flanges; apical process and titillator absent. Inferior appendages stout and longer than subgenital plate; in lateral view almost parallel-sided, directed caudad for proximal 5/6, abruptly tapered and curved dorsad at 1/6 length; with many setae, in particular bearing long sharp setae for distal 1/2 of dorsal margin.

Female. Lengths of forewing, hindwing and body 2.5–2.8 mm, 2.0– 2.4 mm and 2.6–3.3 mm, respectively (n=5). Antennae 24–25-segmented; length 0.9–1.0 mm (n=5). Abdomen increasingly darker from anterior to posterior; segment VII the darkest and most hirsute. Ventral process of sternite VI small, apically subacute. Segment VIII tapered slightly in lateral view; tergite and sternite fused, forming heavily sclerotized annulus; in dorsal view tergite rectangular with rounded postero-lateral angles and 3 pairs of subapical setae; sternite also elongate rectangular with rounded postero-lateral angles and 4 pairs of setae. Bursa copulatrix heart-shaped.

Specimens examined. Hokkaido: 11 males, 77 females, Shibetsu-cho, Po-gawa, Pogawa-bashi, 22.VII– 12.VIII.1996, TI et al., L; 78 males, 193 females, Shibecha-cho, Kayanuma, Shirarutoro-etoro-gawa, Tomi-bashi, 25.VII.2008, TI, P; 90 males, 266 females, Shibecha-cho, Kayanuma, Shirarutoro-etoro-gawa, 17 m, 16.VII.2009, TI, P; 1 male, Shibecha-cho, Shirarutoro-ko, Togan, 25.VII.2008, TI, L; 1 female, Kushiro-shi, Aikoku, 2.VIII.1986, M. Itou; 1 male, 1 female, Kushiro-shi, Iwabokki, 3.VII.1987, M. Itou; 1 male, Kushiro-shi, Akancho, Akan-kohan, Ibeshibetsu, 21.IX.1996, TI & AO, L; 3 males, 6 females, ibid., 26.VII.1999, TI & AO, L; 5 females, ibid., 9.VIII.2007, TI, L; 1 male, 12 females, Kushiro-shi, Akan-cho, Ibeshibetsu-gawa, 425m, 14.VII– 13.IX.1997, TI & AO, L; 1 male, 20 females, ibid., 27.VII.1999, TI & AO, L; 1 female, Sarufutsu-mura, Sarufutsugawa, Shobu-bashi, 31.VII.2007, TI, L; 10 males, 5 females, Sarufutsu-mura, Nigori-kawa, Wakakusa-bashi, 1.VIII.2007, TI, P; 1 female, Horonobe-cho, Sarobetsu, Nakanoshima, small pond, 7.VII.2007, TI, S; 1 female, Honbetsu-cho, Benkeido, 21.VII.1980, TI, L; 1 female, Taiki-cho, Kimonto-gawa, Numakawa-bashi, 2.VIII.2007, TI, L. Honshu. Niigata: 5 females, Nagaoka-shi, Oyazawa, 9.VIII.2000, NKA, L (MKNM).

Remarks. The dorsal plate of male of this species was figured in lateral view but not in dorsal view in either the original description of Xue & Yang (1990) or the redescription of Arefina et al. (2002), probably due to its almost complete transparency. The male of this species is characterized by the elongate triangular dorsal and subgenital plates and upwardly curved inferior appendages. The female of this species resembles that of H. phenianica , the most abundant species in the main islands of Japan, but is distinguishable from that species by the long rectangular tergite of segment VIII.

Distribution. Japan (Hokkaido, Honshu), China, Russian Far East (continental parts).

Habitat. Adults were collected near lowland streams.

Japanese name. Chaina-hime-tobikera.

Figures

FIGURE 14. Distributions of 12 species of Hydroptila in Japan and adjacent areas. For clarity, nearby collection sites in Japan are grouped together as a single point and the sites are roughly plotted in adjacent, non-Japanese areas.

FIGURES 3 – 4. 3, H. chinensis: A – C, male; A—abdominal segments VII – X, lateral; B—genitalia, dorsal; C—same, ventral; D-F, female; D—abdominal segments VIII, lateral; E—same, dorsal; F—abdominal segments VII – X, ventral. 4, H. ogasawaraensis: A – E, male; A—abdominal segments VIII – X, lateral; B—genitalia, dorsal; C—apex of subgenital plate, variation, dorsal; D—genitalia, ventral; E—phallic apparatus, lateral; F – H, female; F—abdominal segments VII – X, lateral; G—same, ventral; H—abdominal segment VIII, dorsal.