Stactobia makartschenkoi Botosaneanu & Levanidova 1988

Ito, Tomiko, 2017, The genus Stactobia McLachlan (Trichoptera, Hydroptilidae) in Japan, Zootaxa 4350 (2), pp. 201-233 : 203-208

Stactobia makartschenkoi Botosaneanu & Levanidova 1988

( Figs 1–3 , 18 )

Stactobia makartschenkoi Botosaneanu & Levanidova 1988 , 169–172, holotype male, larva, case, Kuril Islands (Kunashir). Botosaneanu & Nozaki 1996, 55, habitat, Hokkaido (Ishikari), Honshu (Niigata, Shizuoka); Kuhara et al. 2007, 68, Hokkaido (Ishikari); Ito et al. 2010, 57, Hokkaido (Shiribeshi, Hiyama, Oshima); Ito 2013, 51, 80, Hokkaido (Nemuro, Okhotsk).

Diagnosis. This species belongs to the Stactobia martynovi Species Group, and is distinguished from congeneric Japanese species in the male by the shape of the 2 slender spines of the phallus and in the final instar larva by the shapes and arrangements of the sternites of the pro- and mesothoraces.

Description. Adult. Antennae black, each 18-segmented. Tibial spur formula 1, 2, 4.

Male ( Figs 1A–1F ). Antennae 0.9–1.0 mm long (n = 5). Length of each forewing and hind wing 2.0– 2.5 mm and 1.9–2.0 mm, respectively (n = 5).

Genitalia. Tergite VII longer than sternite VII, ventral process long, with expanded spiny apex. Tergite VIII longitudinally shorter than sternite VIII. Tergite IX with pair of long anterior apodemes, sternite IX reduced. Tergite X membranous pair of with weakly sclerotized oblique bands dorsolaterally. Subgenital appendages (superior appendages of Botosaneanu & Nozaki, 1996) very small, transversely linear and sinuous with round mesal ends. Inferior appendages small, rectangular with irregularly protruded margins. Phallus tubular, slightly sinuate, flattened and somewhat broadened at apical 1/3, spoon-shaped apically, with 2 spines internally; spines slender, 20–30 times as long as basal width, slightly sinuate, slightly different in length.

Female ( Figs 1G– 1I ). Antennae 0.7–0.8 mm long (n = 3). Length of each forewing and hind wing 2.4–2.7 mm and 2.1–2.6 mm, respectively (n = 3). Internal apparatus ovoid in ventral view.

Final instar larva ( Figs 2A–2M ). Sclerites dark brown. Head width up to 0.30 mm, body length up to 2.4 mm. Setae of pro-, meso-, and metanota numbering about 30, 20, and 15, respectively; ecdysial line of mesonotum with notch at posterior 1/5. Two pairs of slender sclerites near posterior margin of prothorax ventrally, anterior one obliquely long, posterior one L-shaped. Pair of very short, transversely wide sclerites near posterior margin of mesothorax ventrally. Other features typical of genus.

Early instar larvae ( Figs 3A–3E ). Muscular, resembling beetle larva in appearance, dark brown, with many stout setae on head, thorax, and abdomen, length up to 0.9 mm.

Head. Subtrapezoidal, 0.24 mm wide in penultimate instar; dorsal ecdysial lines distinct, longest seta (seta no. 9, sensu Wiggins 1996) 1.5 times width of head, antennae near anterolateral corners, each with fine seta subapically.

Thorax. Dorsal ecdysial lines absent. Pronotal plate subquadrate dorsally with pairs of long thick setae and many short, slender setae, short spine-like setae on anterior edge and anterolateral corners. Meso- and metanotal plates wide, lateral margins slightly convex laterally, with 2–3 long stout setae at each anterolateral corner; in total bearing about 28, 12, and 14 setae on pro-, meso-, and metanota, respectively. Thoracic legs short and stout; all legs similar in form; tibial spurs acute apically, each subtended by 2 small spines.

Abdomen. Tapering from anterior to posterior. Wide rectangular dorsal plates on terga I–VIII and semicircular dorsal plate on tergum IX. Dorsal plates on segments I–VII slightly convex laterally, each with pair of long stout setae laterally and near posterolateral margin, but no setae longer than body width; several short setae dorsally and short spines laterally. Venters of segments I–VIII each with 2 pairs of long setae at setal area 2. Tergite IX with 4 pairs of long stout setae on posterior margin and several short setae dorsally. Anal legs curved anterolaterad, anal claws without accessary hooks.

Case ( Figs 3F, 3G ). Made of silk, sometimes incorporating few mineral particles, composed of ventral and dorsal valves; ventral valve flat; dorsal valve dome shaped, longer than ventral valve, with anterior and posterior hoods broader and concealing larva completely, tiny notch at middle edge of anterior and posterior hoods; up to 2.6 mm. Before pupation anterior and posterior edges of cases fixed to substrate and with reduced anterior and posterior hoods.

Specimens examined. HOKKAIDO. Tokachi: 1 male, Sintoku-cho, Yutomuraushi-gawa , 26.ix.1998, K. Endo. Kamikawa: 22 males, Kamikawa-cho, Pon-rubeshibe-gawa, Keimei-bashi , 11.vi.1998, AO; 13 males, Furano-shi, Yamabe, Honzawa, 19.vii.2006, TI. Ishikari: 50 males, Ishikari-shi, Hamamasu, Shiragane-no-taki, 7.vii.2006 – 8.vii.2009, TI; 53 males, 44 females, 15 pupae, 415 final instar larvae, 9 early instar larvae, Ishikari-shi, Hamamasu, Gokibiru-gawa, 1–37 m a.s.l., 12.vi.2000 – 29.x.2001, TI; 1 male, Sapporo-shi, Mt. Soranuma-dake , 1.vii.1989, NK; 19 males, Sapporo-shi, Takino, 8.vi.1978, TI; 51 males, Sapporo-shi, small stream near Nakayama Pass , 28.vi.1992, NK; 1 male, Eniwa-shi , Rarumanai-no-taki , 6.vii.2017; 5 males, Chitose-shi , Bifue-no-taki , 30.vii.2006, TI & TH. Shiribeshi: 1 male, Otaru-shi, Okusawa, Ana-taki, 12.vii.2001, AO; 21 males, Rankoshicho , Momiji-no-taki , 1–7.vii.1997, K. Okazaki; 6 males, Shimamatsu-mura, Yunosawa-gawa, 10.vi.2009, TI. HONSHU. Iwate: 2 males, Miyako-shi, Kawai-mura, Yakushi-gawa, 500 m a.s.l., 10.viii.1994, TH; 5 males, Nishi-wada-cho, Yuda, Koita-gawa, 12.VIII.1994, TH; 1 male, Kitagami-shi, Motouchi-gawa, small tributary, 20.vi.1997, TH; 9 males, Tono-shi, Tochiuchi, 29.vii.1998, N. Kawase. Miyagi: 2 males, Sendai-shi, Futakuchi, Natori-gawa, 400 m a.s.l., 8.vi.1994, TH. Yamagata: 2 males, Iide-machi, Hirogawara-gawa, Higashi-zawa, 500 m a.s.l., 3.vii.1998, TH. Saitama: 13 males, Chichibu-shi, Otaki-mura, Kudono-sawa, 20.v.1998, TI & AO. Niigata: 1 male, Shibata-shi, Uchinokura-gawa, 200 m a.s.l., 7.vii.1997, TH; 1 male, Itoigawa-shi, Kotaki-gawa, Tsuchikura-zawa, 280 m a.s.l., 11.vi.1998, TH; 1 male, Aga-cho, Kanose, Koara, 13.vi.1998, M. Maruyama; 1 male, Yuzawa-machi, Tsuchitaru, 26.vi.2001, K. Endo. Toyama: 2 males, Nanto-shi, Taira-mura, Nachidani-gawa, 450 m a.s.l., 30.vii.1995, TH. Nagano: 5 males, Kiso-fukushima-cho, Biological Station of Kyoto University , 31.vi.1993, NK. Gifu: 1 male, Takayama-shi, Nyukawa, Kute, Hirayu Tunnel, 20.ix.1998, HN. Hyogo: 4 males, Chigusa-cho , 22.ix.1997, HN. Tottori: 1 male, Misasa-cho, Kijiyama, Tenjin-gawa, tributary, 24.v.1993, NK; 1 male, Nichinan-cho, Yukawa, Wakamatsu-gawa, 580 m a.s.l., 14.ix.2002, TH. Shimane: 1 male, Masuda-shi, Hikimi-cho, Oku-hikimi-kyo, 24.v.1993, NK. Okayama: 1 male, Nagi-cho, Takimoto, Takiyama, 24.ix.2011, KN; 18 males, Kagamino-cho, Koshiwata, 13.viii.2011, KN; 12 males, Kagamino-cho, Kamisaibara, Endo, 14.viii.2011, KN; 5 males, Nagi-cho, Maguwa, 3.v.2012, KN; 4 males, Tsuyama-shi, Okutsugawa, 5.v.2011, KN; 34 males, Maniwa-shi, Hiruzen-kamifuda, 5.v.2016, KN; 5 males, Niimi-shi, Osa-oino, Fushitani, 8.v.2016, KN; 44 males, Nishi-awakura-son, Ogaya , 12.v.2016, KN; 2 males, same locality , 20.vii.2016, KN; 3 males, same locality , 24.vii.2016, KN; 47 males, Tsuyama-shi, Aba, 13.v.2016, KN; 37 males, Tsuyama-shi, Kamo-cho, Kurami, 4.vi.2016; 3 males, Kagamino-cho, Tominishi-dani, Shiraga-keikoku, 26.vi.2016, KN. SHIKOKU. Ehime: 54 males, Uchiko-machi, Odamiyama-keikoku, 800 m a.s.l., 20–22.iv.2000, TI & AO. KYUSHU. Fukuoka: 4 males, Toho-mura, Hushuyama, Houshuyama-gawa, headwater, 8.iv.1997, TN. Nagasaki: 5 males, Isahaya-shi, Takagi-cho, Todoroki-kyo, 18.ix.2000, AO. Oita: 11 males, Kokonoe-machi, Tano, Naruko-gawa, 900 m a.s.l., 18.ix.2002, TH. Kagoshima: 8 males, Okuchi-shi, Kogihara, Jusso-gawa, 480 m a.s.l., 20–21.iv.2004, TH.

Distribution ( Fig. 18 ). Kuril Islands (Kunashir); Hokkaido (Okhotsk, Nemuro, Tokachi, Kamikawa, Ishikari, Shiribeshi, Hiyama, Oshima); Honshu (Iwate, Miyagi, Yamagata, Saitama, Niigata, Toyama, Nagano, Gifu, Hyogo, Tottori, Shimane, Okayama); Shikoku (Ehime); Kyushu (Fukuoka, Nagasaki, Oita, Kagoshima). Newly recorded for Shikoku and Kyushu. This is the most widespread Stactobia species in Japan.

Habitat and life cycle. The above colleagues and I found larvae and pupae of this species living on smooth rock surfaces of waterfalls and very fast-flowing waters. My monthly collecting in a rapidly flowing stream (Gokibiru-gawa, Ishikari-shi, Ishikari, Hokkaido) during 2000–2001, clearly revealed that this species is univoltine, the adults appearing over summer (June to August).

Japanese name. Kawa-kaku-himetobikera.

Remarks. This is the first description of the early instar larva for this species.

Figures

FIGURE 1. Stactobia makartschenkoi Botosaneanu & Levanidova 1988. Male and female. 1 A – 1 F, male: 1 A, head and thorax, dorsal; 1 B, abdominal segments VII – X, left lateral; 1 C, abdominal segments IX – X, ventral; 1 D same, enlarged; 1 E, abdominal segments IX – X, dorsal; 1 F, phallus, dorsolateral. 1 G – 1 I, female: 1 G, posterior part of abdomen, left lateral; 1 H, same, dorsal; 1 I, same, ventral. Abbreviations: ia = inferior appendage; sa = subgenital appendage; sp = spine; VI, VII, VIII, IX, X = abdominal segments VI – X. Specimens: Hokkaido, Ishikari-shi. Scale bars: 0.1 mm for 1 A & 1 B.

FIGURE 2. Stactobia makartschenkoi Botosaneanu & Levanidova 1988. Final instar larva. 2 A, habitus, right dorsolateral; 2 B, head, dorsal; 2 C, head, ventral; 2 D, left antenna, dorsal; 2 E, labrum, dorsal; 2 F, mandibles, dorsal; 2 G, right half of thorax, dorsal; 2 H, pro- and mesosterna, ventral; 2 I, right middle leg, dorsal; 2 J, same, anterior parts, enlarged; 2 K, abdominal segments I – III, dorsal; 2 L, posterior part of abdomen, dorsolateral; 2 M, dorsal and lateral margin of dorsal sclerite of segment IX. Abbreviations: I, II, III, VII, VIII, IX = abdominal segments I – III and VII – IX, respectively. Specimens: Hokkaido, Ishikarishi. Scale bars: 1.0 mm for 2 A; 0.1 mm for 2 B.

FIGURE 3. Stactobia makartschenkoi Botosaneanu & Levanidova 1988. Early instar larva and case of final instar larva. 3 A – 3 E, early instar larva: 3 A, habitus, dorsal; 3 B, right antenna, dorsal; 3 C, tarsal claw of right foreleg, dorsolateral (morphologically posterior); 3 D, dorsal sclerite of abdominal segment IV, dorsal; 3 E, claw of right anal leg, right dorsolateral (morphologically right lateral). 3 F, 3 G, case of final instar larva: 3 F, dorsal; 3 G, ventral. Specimens: Hokkaido, Ishikari-shi. Scale bars: 0.1 mm for 3 A; 1.0 mm for 3 F & 3 G.

FIGURE 18. Distributions in Japan of 6 species of Stactobia.