Hydroptila introspinata Zhou & Sun 2009

Ito, Tomiko & Shimura, Noriyoshi, 2019, Notes on six microcaddisfly species (Trichoptera: Hydroptilidae) recorded for Japan, one a newly described species, Zootaxa 4629 (1), pp. 26-38 : 26-38

Hydroptila introspinata Zhou & Sun 2009

( Fig. 3 )

Hydroptila introspinata Zhou & Sun in Zhou et al. 2009 , 906–908, male, northeastern China; Park et al. 2018, 103–104, Korea.

Revised description. Adult. Wings in alcohol brown without any dots. Wing length: males (n = 5), forewings each 2.4–2.7 mm, hind wings each 2.0– 2.4 mm; females (n = 5) forewings each 2.6–2.9 mm, hind wings each 2.4–2.7 mm. Antennae brown; in males (n = 5), each 1.3–1.4 mm long, 29–30-segmented; in females (n = 5), each 0.8–1.0 mm long, 24–25-segmented. Long thick ventromesal process on segment VII in males and short ventromesal process on segment VI in females.

Male ( Figs 3 A–3E). Segment IX with roundly produced anterolateral margins and pair of setose lateral processes (l.p.); lateral processes directed caudad, subacute apically. Tergite X composed of large dorsal plate (d.pl.) and pair of spinous processes (s.pr.); dorsal plate semitransparent, semicircular in dorsal and ventral views, with 4 pairs of thick spines in transverse row at median section ventrally; spinous processes emerging laterally from ventral half of tergite, each with basal half broad and abruptly narrowing to spinous apical half, directed caudad in lateral view and mesocaudad in ventral view. Subgenital plate (s.pl.) membranous, broadly convex with small shallow concavity apicomesally, distinctly shorter than dorsal plate. Inferior appendages (i.a.) strongly sclerotized, rod-shaped in lateral view, broad basally and narrowing and diverging in ventral view, each with many thick and fine setae at distal 2/3. Phallic apparatus long, almost straight, with constriction at middle, slender distally; titillator absent; aedeagus (ae.) shorter than subapical process (sub.pr.).

Female ( Figs 3 F–3H). Segment VIII cylindrical, with 3 pairs of long setae in transverse row ventrally and pair of long setae dorsally at midlength, setae slightly twisted, ventral sclerite dark and conspicuous, lozenge-shaped in ventral view, bearing numerous very fine spines on surface. Vaginal apparatus narrow, long, sublanceolate.

Specimens examined. Japan, Hokkaido: 1 male, Eniwa-shi , Honryu-2-go-bashi, 21.viii.2009, T. Ito, light pan trap ; 3 males, Chitose-shi, Monbetsu-gawa , 240 m, 14.vii.2000, T. Ito et al., light trap ; 1 male, Kuromatsunai-cho, Utasai, Utasai-gawa , 16.vi.2005, N. Kuhara. Honshu : Iwate: 2 males, Ôshu-shi, Koromogawa-ku , Ômori, 19– 20.vi.2007, T. Ito, light. Shikoku : Ehime: 7 males, 7 females, Oda-cho, Koyamama , 6–22.vi.2000, E. Yamamoto & M. Doi, Malaise trap ; 1 male, 1 female, Kumakogen-cho, Omogo, small stream near Omogo Mountain Museum, 23.v.1999, T. Ito & A. Ohkawa ; 4 males, 12 females, same locality, 8.vi.2011, T. Nozaki et al . Kochi: 2 males, Nangoku-shi, Nakanokawa , 14.v.2004, M. Takai ; 3 males, Higashi-tsuno-mura, Tengu-ike , 8.v.2004, M. Takai ; 1 male, 2 females, Shukuge-shi, Isshobara , 30.iv.2004, M. Takai. Kyushu: Miyazaki : 2 males, 2 females, Kitagawa-cho, Kumata, Kita-gawa , 15 m, 22.iv.2004, T. Hattori .

Distribution. China (Heilongjiang), Korea (Gyeongsangbuk-do), Japan (Hokkaido, Honshu, Shikoku, Kyushu). New to Japan.

Remarks. Males of this species are very similar to those of Hydroptila spinosa Arefina and Armitage 2003 , known in the Russian Far East and Japan, in having a large semicircular dorsal plate with 4 pairs of spines ventrally and strongly sclerotized divergent inferior appendages. However, H. introspinata is clearly distinguished from H. spinosa by the presence of the spinous processes of tergite X. Females of this species, described here for the first time, are very similar to those of H. spinosa ; they are not discriminated from each other in the present study. This species is recorded in Japan for the first time, and some of the specimens in the samples listed above were misidentified as H. spinosa by Ito et al. (2011). This species was found together with H. spinosa in several localities in Hokkaido and Honshu, and found without H. spinosa in all localities in Shikoku and Kyushu.

Japanese name. Hari-hime-tobikera (newly given here).

Figures

FIGURE 3. Male and female of Hydroptila introspinata Zhou & Sun 2009. 3A–3E, male: 3A, genitalia, left lateral; 3B, same, dorsal; 3C, same, ventral; 3D, phallic apparatus, left lateral; 3E, ventral process of segment VII. 3F–3H, female: 3F, abdominal segments VII–X, left lateral; 3G, same, ventral; 3H, vaginal apparatus, ventral. Abbreviations: VII–X = abdominal segments VII–X; ae. = aedeagus; d.pl. = dorsal plate; d.pr. = dorsal process; i.a. = inferior appendage (paired); l.p.= lateral process (paired); sub.pr. = subapical process; s.pl. = subgenital plate.; s. pr. = spinous process (paired). Scale bars = 0.1 mm.