Hydroptila nanseiensis Ito

Ito, Tomiko, Ohkawa, Ayuko & Hattori, Toshio, 2011, The genus Hydroptila Dalman (Trichoptera, Hydroptilidae) in Japan, Zootaxa 2801, pp. 1-26 : 15

Hydroptila nanseiensis Ito , sp. nov.

( Figs. 8 , 14 D)

Adult. Wings dark brown with several small lighter markings. Antennae brown to light brown with darker markings apically.

Male. Lengths of forewing, hindwing and body 2.2–2.5 mm, 1.6–2.2 mm and 2.1–2.5 mm (n=5), respectively. Antennae 29–35-segmented; length 1.1–1.5 mm (n=5). Ventral process of sternite VII stout and elongate, apex with rugose sculpturing. Segment IX with rounded apodemes; lateral processes elongate, rod-shaped in dorsal and ventral views, in lateral view broadly triangular, apically rounded, surface rough towards apex. Dorsal plate composed of median plate and lateral arms: Median plate shorter than wide, in dorsal view rectangular, in lateral view slightly curved dorsad; lateral arms strongly sclerotized, rod-shaped with apices truncate in dorsal and lateral views. Subgenital plate membranous, thick, shorter than lateral arms of dorsal plate. Phallic apparatus stout and elongate, with titillator and triangular, flag-like subapical process. Inferior appendages short, rounded and leaf-like in ventral view, curved dorsad in lateral view, with 2 strong setae mesally and 1 long seta at baso-mesal angle.

Female. Lengths of forewing, hindwing and body 2.0- 2.8 mm, 1.8–2.4 mm and 2.3–3.6 mm, respectively (n=5). Antennae 25–28-segmented; length 0.9–1.1 mm (n=5). Sternite of segment VIII trapezoidal with wide semicircular concavity at distal margin in ventral view, dark median ring and conspicuous anterior triangular bands; internal ventral sclerite widely rectangular; with 3 pairs of long ventral margin setae, and pair of fine, short setae on postero-distal margin. Bursa copulatrix narrowly lozenge-shaped.

Holotype: Japan, Okinawa, Yaeyama Islands: 1 male, Ishigaki-jima, Omoto-dake (24˚25’N, 124˚11’E, 80 m), 18–19.III.2002, I. Oshima et al., L (CBM-ZI 145412).

Paratypes. 3 males, 3 females, same data as holotype (CBM-ZI 145413–145418).

Other specimens examined. Okinawa, Okinawa Island: 53 females, Kunigami-son, Yona, Sukuna-gawa, lower reach, 21.III.1999, TI & AO, L; 1 male, 3 females, Kunigami-son, Yona, small tributary of Sukuna-gawa, 22.III.1999, TI & AO, L; 1 male, 2 females, Kunigami-son, Yona-gawa, Nakafukuji-hashi, 23.XI.2010, TI, P; 3 males, 6 females, Nago-shi, Genka-kawa, Hogen-hashi, 22.XI.2010, TI, P. Okinawa, Yaeyama Islands: 144 males, 244 females, same data as holotype; 19 females, Iriomote-jima, Nishi-funatsuki-gawa, Nishi-funatsukibashi, 23.III.1999, TI & AO, L; 4 males, 50 females, Iriomote-jima, Omija-gawa, Omija-bashi, 24.III.1999, TI & AO, L; 9 males, 18 females, Iriomote-jima, Aira-gawa, 25.III.1999, TI & AO, L; 1 male, Iriomote-jima, Maeragawa, 13–14.IV.2005, TI, L.

Diagnosis. The male of this species is similar to that of H. sidong Oláh, 1989 , described from Vietnam ( Oláh 1989) and also found in China ( Zhou et al. 2009), in having the phallic apparatus unique in shape and the lateral process of segment IX triangular, but this species is clearly distinguished from the latter by the broadly rectangular dorsal section of the dorsal plate and short, round inferior appendages.

Etymology. The specific name refers to the name of the islands where this species was collected.

Distribution. Japan (Nansei Islands). Endemic to Nansei Islands.

Habitat. Adults were collected from streams in mountain and lowland areas.

Japanese name. Nansei-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 7 – 8. 7, H. spinosa: A – C, male; A—abdominal segments VII – X, lateral; B—genitalia, dorsal; C—same, ventral; D- F, female; D—abdominal segment VIII, lateral; E—same, dorsal; F—abdominal segments VII – X, ventral. 8, H. nanseiensis: A – E, male; A—ventral process, lateral; B—genitalia, lateral; C—same, dorsal; D—same, ventral; E—left inferior appendage, dorso-lateral; F – H, female; F—abdominal segment VIII, lateral; G—same, dorsal; H—abdominal segments VII – X, ventral.