Pseudoxyethira ishiharai ( Utsunomiya 1994 )

Ito, Tomiko, 2017, The genus Pseudoxyethira Schmid (Trichoptera, Hydroptilidae) in Japan, Zootaxa 4319 (1), pp. 194-200 : 195

Pseudoxyethira ishiharai ( Utsunomiya 1994)

( Figs. 1–8 , 19 )

Scelotrichia ishiharai Utsunomiya 1994 , 345–318, male, female, larva, case, Shikoku (Kochi); Ohkawa and Ito 2002, 449–458, male, female, larva, case, habitat, feeding behavior, Hokkaido (Ishikari, Shiribeshi), Honshu (Yamagata, Tokyo, Kanagawa, Nagano, Gifu, Shizuoka, Aichi), Shikoku (Ehime, Kochi), Kyushu (Nagasaki, Miyazaki); Katsuma 2006, 35, Honshu (Ibaraki); Satake and Kuranishi 2007, 282, Izu Islands (Mikura-jima); Kuhara 2011, 52, 72, Hokkaido (Sorachi); Kuhara and Ito 2017, 16, Yakushima.

Pseudoxyethira ishiharai: Zhou et al. 2016 , 214.

Male ( Figs. 1–8 ). Black. Length of each forewing and hind wing 1.7–2.2 mm and 1.4–2.0 mm, respectively (n = 10); androconia present. Antennae 18-segmented, 0.8 mm long (n = 10). Spur formula 0, 2, 4 or 1, 2, 4, variable individually and locally.

Genitalia. Dorsal plate short, membranous, subquadrate. Inferior appendages long, in ventral view length 4 times maximum width; gradually broadened at first, widest at middle, gradually narrowing in distal half; mesal edges of distal half strongly sclerotized, serrated due to presence of many small spines; subacute or round apically. Phallus long, apically divided into lateral lobe and middle membranous lobe: lateral lobes each with spine apically; middle membranous lobe often difficult to observe.

Specimens examined. Hokkaido: 13 males, Imakane-cho , Oshubunnai-no-taki, 5.vii.2006, TI & TH ; 5 males, Ishikari-shi, Hamamasu-ku, Shiragane-no-taki, 7.vii.2006, TI; 1 male, same locality, 8.vii.2009, TI ; 3 males, Iwanai-cho , Narugami-no-taki, 3.viii.2006, TI & TH ; 1 male, Fukuhsima-cho , Fudo-no-taki, 4.viii.2006, TI & TH. Honshu. Ishikawa: 15 males, Wajima-shi, Machino-cho, Sosogi, 5 m a.s.l., 10.vi.2011, TH. Yamanashi: 1 male, Minobu-cho, Ojiro, 460 m a.s.l., 12.vi.2010, TH. Shizuoka: 2 males, Shizuoka-shi, Mizumiiro-gawa, Ubaga-fuchi, 31.v.1995, TH. Shiga: 1 male, Higashi-omi-shi, Eigenji, Kanzaki-gawa, small fall, 3.ix.2013, TI ; 1 male, same locality, 11.vi.2016, TI. Okayama: 3 males, Nishi-awakura-son, Okaya, 24.vii.2016, K. Nojima. Shimane: 1 male, Misato-cho, Nagato, Hibiki-dani, 6.viii.2001, AO. Shikoku. Tokushima: 1 male, Naka-cho, Konose-kyo, 22.v.2008, M. Takai & TI. Ehime: 1 male, Uwajima-shi, Nametoko-keikoku, 400–600 m a.s.l., 23.ix.2002, TH. Kyushu. Nagasaki: 3 males, Korai-cho, Todoroki-kyo, 18.ix.2000, AO. Oita: 1 male, Kusu-machi, Mori, Shimizu-bakuen, 450 m a.s.l., 18.iv.2004, TH. Ryukyu Islands. Amami-oshima: 7 males, Yamato-son, Materiano-taki, 25–26.x.2011, TI. Okinawa-jima: 4 males, Kunigami-son, Yona-gawa , Heigi-hashi , 10.iv.2011, TI ; 1 male, same locality, 18.iii.2015, TI ; 4 males, Nakijin-son, Shigema-gawa, upper reach, 17.iii.2014, TI; 3 males, Nakijin-son, Shigema-gawa, lower reach, 8.iv.2011, TI. Ishigaki-jima: 1 male, Omoto-dake , small fall near foot path, 26.x.2012, TI ; 3 males, Fukidori-gawa, middle reach, 20.iii.2016, TI. Iriomote-jima: 1 male, Nishifunatsuki-gawa , Nishi-funatsuki-bashi, 30.x.2012, TI ; 9 males, Yuchin-gawa , small fall, 23.x.2015, TI ; 1 male, same locality, 23.iii.2016, TI.

Remarks. This species is distinguished from congeneric species by the shape of the inferior appendages and the phallus: Inferior appendages with serrated mesal edges and apex of phallus divided into 3 parts.

Distribution ( Fig. 19 ). Hokkaido, Honshu, Shikoku, Kyushu, Ryukyu Islands (Yakushima, Amami-oshima, Okinawa-jima, Ishigaki-jima, Iriomote-jima), Izu Islands. New to middle and southern Ryukyu Islands.

Habitat. Adults of this species were collected near waterfalls and rapid streams with large rocks.

Japanese name. Koke-himetobikera.

Figures

FIGURE 19. Distributions of 3 species of Pseudoxyethira in Japan.

FIGURES 1 – 8. Male of Pseudoxyethira ishiharai (Utsunomiya): 1, head and thorax, dorsal; 2, right antenna, right lateral; 3, right wings, dorsal, with enlarged androconia; 4, right tibiae of 3 legs, dorsal, with enlarged apical half of foretibia; 5, genitalia, left lateral; 6, same, dorsal; 7, same, ventral; 8, apex of right inferior appendage, ventral, variation; specimen, Hokkaido, Imakane-cho, Oshubunnai-no-taki. Abbreviations: VII – IX, abdominal segments VII – IX; dp, dorsal plate; ia, inferior appendage; ph, phallus.