Homoplectra albomarginata ( Ulmer 1907 )

Homoplectra albomarginata ( Ulmer 1907)

( Figs 2A–2C View FIGURES 1–2 , 4 View FIGURE 4 , 5 View FIGURE 5 , 12A–12C View FIGURES 11–12 , 13 View FIGURE 13 )

Diplectrona albomarginata Ulmer 1907, p. 74 View in CoL , holotype female, Museum of Natural Sciences of Belgium, Brussels.

Diplectrona japonica View in CoL nec Banks 1906: Ulmer 1907, pp 72–74, pl. 4 fig. 19, male; Kobayashi 1968, p. 3; Hatta and Nozaki 1991, p. 200. Misidentifications.

Diplectrona sp. 2 : Torii and Hattori 2006, pp 37–38.

Diplectroninae View in CoL Gen. sp.: Morita 2009, pp 6–7; Kawase and Morita 2014, p. 5.

Diplectroninae Gen. japonica View in CoL Complex: Nozaki et al. 2014, p. 61; Nojima 2017, p. 119 (in part).

Diplectrona japonica View in CoL Species Complex: Watanabe 2021, pp 41–43, mating behavior.

Homoplectra albomarginata : Nozaki 2021 View Cited Treatment , pp 254–256, figs 6A–6E, female, changed combination.

Homoplectra japonica Species Complex: Higuchi 2024, p. 19.

Diagnosis. Adults of this species and H. japonica are similar to each other in general morphology and coloration, but these species can be distinguished from each other by the length of the antennal scape: Each scape of this species is apparently longer than wide in this species ( Figs 2B, 2C View FIGURES 1–2 ), but as long as wide in H. japonica ( Figs 1C, 1E View FIGURES 1–2 ). The male and female of this species are similar to those of Homoplectra inazui sp. nov. in having long antennal scapes ( Figs 2B, 2C View FIGURES 1–2 ); but are easily distinguishable from the latter by the following characters: In the male, the subapicomesal surface of each inferior appendage bears a small process with a few apical spine-like setae in H. albomarginata ( Fig. 4A View FIGURE 4 ), but many spine-like setae arise directly from the apicomesal surface in H. inazui sp. nov. ( Fig. 10A View FIGURE 10 ); in the female, tergum IX is broadly sclerotized ventrally in H. albomarginata (marked with an arrow in Fig. 4H View FIGURE 4 ) but semi-membranous in H. inazui sp. nov. ( Fig. 10H View FIGURE 10 ). Furthermore, the vaginal apparatus bears an eye-glasses-shaped sclerite posterodorsally in this species ( Fig. 4H View FIGURE 4 ) but lacks such a sclerite in H. inazui .

The larva is distinguishable from known Japanese larvae by the shape of anterior margin of the frontoclypeal apotome given in the diagnosis for H. japonica . Furthermore, abdominal segment VII is lacking the subventral tufts of gills in this species but bears them in the known Japanese species ( Nozaki 2019; Kochi et al. 2023).

Description

Adult ( Figs 2A–2C View FIGURES 1–2 ). General morphology and coloration similar to those of H. japonica , but scape of each antenna apparently longer than wide ( Figs 2B, 2C View FIGURES 1–2 ). Yellow markings on female wings occasionally indistinct or lacking ( Fig. 2A View FIGURES 1–2 3 View FIGURE 3 ). Holotype female lacking distinct markings of wings ( Nozaki 2021, fig. 6A). Forewings each 7.0– 9.5 mm long in male (n = 10), 8.5–11.5 mm long in female (n = 11), 10.3 mm long in female holotype. Antennae shorter than forewings; scape approximately 2 times longer than wide, with long hair-like setae dorsally, each pedicel about 1/4 length of its scape ( Figs 2B, 2C View FIGURES 1–2 ).

Male genitalia ( Figs 4A–4F View FIGURE 4 ). Ventrolateral side of synsclerotized segment IX triangular anteriorly in lateral aspect ( Fig. 4A View FIGURE 4 ); posteroventral lobe triangular in ventral aspect ( Fig. 4C View FIGURE 4 ); dorsal part of segment IX semicircular in dorsal aspect ( Fig. 4B View FIGURE 4 ), broadly fused with segment X laterally ( Fig. 4A View FIGURE 4 ). Segment X tapering to acute apex and bilobed posteriorly in dorsal aspect, pair of posterolateral setose areas protruding posterad ( Figs 4A, 4B View FIGURE 4 ); ventral part membranous, with pair of posterior processes (p.p.X) thick and sword-like ( Figs 4A, 4D View FIGURE 4 ) with base of each process fused with lateral strip (l.s.) of genital chamber ( Figs 4A, 4D View FIGURE 4 ). Genital chamber with pair of lateral strips (l.s.) strongly sclerotized ( Figs 4A, 4D View FIGURE 4 ), rarely with pair of tiny inner processes (i.p.) near base of phallotheca ( Fig. 4D View FIGURE 4 ). Inferior appendages long and finger-like, slightly bent upward at 2/5 from base, truncate apically in lateral aspect ( Fig. 4A View FIGURE 4 ); each apex weakly depressed mesally, with short process bearing few tiny spine-like setae subapicomesally ( Figs 4A View FIGURE 4 inset, 4C). Basal plate of inferior appendages sclerotized, long rectangular in ventral aspect ( Fig. 4C View FIGURE 4 ) and fused anteriorly with anteroventral edge of phallotheca. Phallotheca evenly curved ventrad ( Figs 4A, 4E View FIGURE 4 1 View FIGURES 1–2 , 4E View FIGURE 4 2 View FIGURES 1–2 ); with dorsal process (d.p.p.) and pairs of lateral and ventral processes (l.p.p. and v.p.p.), each apex acute, length of each process variable ( Figs 4E View FIGURE 4 1 View FIGURES 1–2 , 4E View FIGURE 4 2 View FIGURES 1–2 ); with thick ventral spine (v.s.p.) sub-basally ( Figs 4C, 4E View FIGURE 4 1 View FIGURES 1–2 , 4E View FIGURE 4 2 View FIGURES 1–2 ). Aedeagus ( Fig. 4F View FIGURE 4 ) evenly curved ventrad; stem with lateral flanges, half-pipe-like; head approximately 1/10 of stem.

Female genitalia ( Figs 4G–4J View FIGURE 4 ). Lateral lobes of sternum VIII (l.l.) widely separated from each other ventrally ( Fig. 4I View FIGURE 4 ). Segment IX obliquely rectangular in lateral aspect ( Fig. 4G View FIGURE 4 ), trapezoidal in dorsal aspect ( Fig. 3H View FIGURE 3 ); ventral surface of tergum broadly sclerotized, wing-like in dorsal aspect (marked with an arrow in Fig. 4H View FIGURE 4 ); mesal lobe (m.l.IX) weakly sclerotized, oval in lateral aspect ( Fig. 4G View FIGURE 4 ), each forming large pocket-like crevice between it and segment IX in ventral aspect (marked with an arrow and asterisk in Fig. 4I View FIGURE 4 ); pair of sclerotized ribs (s.r.) forming pair of short round plate-like lobes on vulvar scale basoventrally ( Fig. 4I View FIGURE 4 ), but shape of lobes variable ( Figs 4J1–4J3 View FIGURE 4 View FIGURES 1–2 View FIGURE 3 ). Vulvar scale (v.s.) large, tongue-like, its apical margin with small median protrusion ( Fig. 4I View FIGURE 4 ); with pair of deep holes basolaterally. Segment X setose, tall and longitudinally shot in lateral aspect ( Fig. 4G View FIGURE 4 ). Vaginal apparatus (v.a.) long pentagonal in dorsal aspect ( Fig. 4H View FIGURE 4 ), tapering to duct of bursa copulatrix; with eye-glasses-shaped sclerite posterodorsally, with pair of longitudinal ridges dorsally, and with dark arched marking anterodorsally, partially surrounding opening of duct of spermatheca (d.s.).

Variations of male and female genitalia ( Fig. 5 View FIGURE 5 ). As described above, some of females collected from Moroka, Sakauchi-sakamoto, Ibigawa-cho, Gifu, have genitalia, especially a pair of basoventral lobes on the vulvar scale, very similar to those of the holotype female ( Fig. 4I View FIGURE 4 ; Nozaki 2021, fig. 6C) although the shape is variable even at the same site ( Figs 4J1–4J3 View FIGURE 4 View FIGURES 1–2 View FIGURE 3 ). In males in this population, the lengths of the processes of the phallotheca are also variable ( Figs 4E View FIGURE 4 1 View FIGURES 1–2 , 4E View FIGURE 4 2 View FIGURES 1–2 ). Furthermore, males collected nearby, in the same town, where females have their genitalia indistinguishable to those of the Moroka population, each bear a pair of distinct inner processes of the genital chamber, and the length of these processes is variable ( Figs 5A View FIGURE 5 1 View FIGURES 1–2 , 5A View FIGURE 5 2 View FIGURES 1–2 ). In other areas, different forms of the male genitalia are found not only in the above-mentioned characters but also in the shapes of segment X, the posteroventral lobe of segment IX, inferior appendages, the head of the aedeagus, and the presence or absence of the ventral spine of the phallotheca. Females collected with these males often have genitalia slightly different from those of the Moroka population, especially in the shape of the vulvar scale and vaginal apparatus. Some examples of these male and female variations are shown in Figs 5B–5F View FIGURE 5 ; although these forms are often variable even in the same locality.

Final instar larva ( Figs 12A, 12C View FIGURES 11–12 ). Head 1.3–1.8 mm wide (n = 8), slightly longer than wide ( Fig. 12A View FIGURES 11–12 ); frontoclypeal apotome asymmetrical in dorsal aspect, anterior margin evenly convex mesally, concave laterally, left side recessed, secondary setae acicular ( Fig. 12B View FIGURES 11–12 , inset); posterior angle 82°–85°, maximum width 0.9–1.2 mm. Meso- and metathorax and abdominal segments bearing gills, with one pair of ventral tufts of gills on mesothorax and abdominal segment VII, with two pairs of ventral tufts of gills on metathorax and each of abdominal segments I to VI, with 1–3 lateral conical gills on each of abdominal segments III to VII.

Pupa ( Fig. 12C View FIGURES 11–12 ). Body length 9.5–12 mm (n = 5). Anal processes ( Fig. 12C View FIGURES 11–12 ) sclerotized, not bifurcate, ventral surfaces covered by tiny spines, with apices acute and directed dorsad. Other characters similar to those of H. japonica ( Figs 11C–11E View FIGURES 11–12 ).

Specimens examined. JAPAN: HONSHU: Niigata: 1 female, Mt. Amakazari, Itoigawa-shi , 26.vi.1955, K. Baba ( KPM); 1 female, Mushi-gawa (alt. 170 m), Oyachi, Itoigawa-shi , 27.v.1995, T. Hattori ( SPMN); 1 female, Fudo-no-taki (alt. 300 m), Oyachi, Itoigawa-shi , 27.v.1995, T. Hattroi ( SPMN). Toyama: 1 male, Nashitani-gawa, Ainokura, Nanto-shi , 17.vi.2018, Y. Higuchi. Ishikawa: 3 male, 3 females, Hodatsushimizu-cho , 2–26.v.1990, I. Togashi ( KT); 1 male, Sannomiya, Tsurugi, Hakusan-shi , 18.iv.1984, I. Togashi ( KT); 1 male, Sunagozen, Hakusan-shi , 25.v.1980, I. Togashi ( KT); 1 male, Odani, Chugu, Hakusan-shi , 28.v.2016, Y. Higuchi; 2 males, Ushikubi-gawa, Shiramine, Hakusan-shi , 8.vi.2021, Y. Higuchi; 1 female, small stream, Ushikubi-gawa, Shiramine, Hakusan-shi , 2.vii.2023, Y. Higuchi; 1 male, 2 females, Ohirasawa, Kanazawa-shi , v.1982, M. Eguchi ( KT); 1 male, Nabetani, Nomi-shi , 29.iv.1990, Y. Sugie ( KT); 20 males, same locality, 1.v–5.vi.1993, Y. Sugie ( KT); 2 males, Dainichi R., Maruyama, Komatsu-shi , 17.vi.1982, K. Tanida ( KT). Fukui: 2 males, 1 female, Kitadanicho-obara, alt. 1400 m, Katsuyama-shi , 27.vii.2003, K. Inazu; 1 male, Nyu, Mihama-cho , 21.v.2001, N. Kawase ( NK); 2 males, 1 female, Misaka-dani, Oono-shi , 10.vi.2006, T. Torii ( SPMN); 1 male, Shimoshinjo, Sabae-shi , 6.v.1986, H. Nishida ( KT); 1 male, Nokatani (alt. 310m), Notaoi, Natasho, Ohi-machi , 25.iv.2010, T. Hattori ( SPMN). Nagano: 1 male, Aoni-sawa (alt. ca. 850 m), Hakuba-mura , 11.vi.1995, T. Hattori ( SPMN); 3 males, 2 females, Kamikochi, Azumi, Matsumotoshi , alt. 1510 m, 4.vii.2010, K. Tojo ( SUMNS); 1 male, 1 female, nr. Mizuki-sawa, Ogiso, Kiso-mura , alt. 1300 m, 13.vi.2012, T. Nozaki; 1 male, Chigono, Fukushima, Kiso-machi , 31.v.1993, N. Kuhara (KuN); 2 females, Komanoyu, Fukushima, Kiso-machi , 31.v.1993, N. Kuhara (KuN). Gifu: 5 males, Ozu, Ibigawa-cho , 14–16.v.2001, N. Kawase ( NK); 10 males, 1 female, same locality, 13.v.2002, N. Kawase; 31 males, 4 female, 5 pupae, 2 prepupae, 1 larva, Hin-dani, Ibi-gawa (alt. 400 m), Ibigawa-cho , 3–4.v.1996, T. Hattori ( SPMN); 4 males, 1 female, 1 larva, Nishimaenotani, Tsurumi, Ibigawa-cho , 10.iv–1.vi.2002, N. Kawase ( NK); 5 males, 6 females, Moroka, Sakauchi-Sakamoto, Ibigawa-cho , 20.iv–8.v.2023, N. Kawase, Malaise trap ( KPM); 2 males, 1 female, same data except collecting date 8.v–18.v.2023 ( NK); 10 males, 8 females, same data except collecting date 18.v–12.vi.2023 ( KPM); 1 female, same data except collecting date 12.vi–29.vi.2023 ( NK); 3 males, 1 female, same locality, 9.v.2024, N. Kawase; 1 male, Meiho-kera, Gujo-shi , 2.v.1992, T. Hattori ( SPMN); 2 females, 1 female, Iwai-machi (alt. 1220 m), Takayama-shi , 9.vi.2011, T. Hattori ( SPMN); 1 female, Kokufu, Takayama-shi , 9.vi.2019, H. Suzuki; 1 female, Amou, Kawai-cho, Hida-shi , 20.vi.2020, N. Kawase ( NK); 3 males, 1 female, Fudo-daki, Tsukechi-cho, Nakatsugawa-shi , 21.v.1996, T. Nozaki ( KPM); 1 male, 1 female, Shinden, Fukuoka, Nakatsugawa-shi , 21.v.1996, T. Nozaki ( KPM). Shizuoka: 2 males, Nishigochi-gawa, Umegashima, Aoi-ku, Shizuoka-shi , 1.v.2010, T. Torii ( TT); 1 male, 1 female, Nyujima, Aoi-ku, Shizuoka-shi , 5.v.1997, T. Hattori ( SPMN); 3 males, 3 females, same locality, 9.v.1999, T. Hattori ( SPMN); 1 male, same locality, 9.v.2006, T. Torii ( TT); 1 female, Hirano, Aoi-ku, Shizuoka-shi , 11.v.1996, T. Hattori ( SPMN); 1 male, Yunno, Shizuoka-shi , 29.iv.1989, T. Hattori ( SPMN); 1 male, Dainichi, Ikawa, Aoi-ku, Shizuoka-shi , 21.v.2003, T. Hattori ( SPMN); 1 male, Uchimaki-gawa, Shizuoka-shi , 1.v.2001, T. Hattori ( SPMN); 1 male, Sumata-kyo, Senzu, Kawanehon-cho , 4.vi.2007, T. Hattori ( SPMN); 1 male, 4 females, same locality, 4.v.2010, T. Torii ( TT); 1 male, Utoge-no-taki, Setonoya, Fujieda-shi , 2.viii.2001, T. Torii ( TT); 1 male, same locality, 18.v.2003, T. Torii ( TT); 2 females, Yamame-dani, Setonoya, Fujieda-shi , 8.v.2004, T. Torii ( TT); 3 males, 1 female, Ookaya-gawa, Kamiooka, Shimada-shi , 26.iv.2002, T. Torii ( TT). Aichi: 2 males, 1 female, 1 pupa, 8 larvae, Mennoki-toge, Tsugu, Shitara-cho , 27.v.1990, T. Nozaki ( KPM); 3 males, same locality, 14.v.1991, T. Nozaki ( KPM). Mie: 1 male, Mt. Nonobori, Kameyama-shi , 8.v.1994, H. Morita ( KT); 7 males, 2 females, Miyazuma-kyo, Suizawa-cho, Yokkaichi-shi , 26.v.2009, H. Morita; 12 males, 1 female, Yunoyama, Komono-cho , 19.v.2005, H. Morita; 1 male, Kawachi-dani (alt. 300 m), Yamaguchi, Fujiwara-cho, Inabe-shi , 4.vi.2006, H. Morita, T. Nozaki & T. Hattori ( SPMN). Shiga: 18 males, 1 female, Ibuki, Maibara-shi , 1.v.1985, H. Nishimoto ( KT); 33 males, 22 females, Ojigahata, alt. 600 m, Taga-cho , Shiga, 10.v–8.vi.2008, H. Morita; 1 male, Ohara, Yogo-cho, Nagahama-shi , 17.v.2010, N. Kawase ( NK); 4 males, 1 female, Nakanokawachi, Yogo-cho, Nagahama-shi , 17.v–26.vi.2010, N. Kawase ( NK); 9 males, Shiratani, Makino-cho, Takashima-shi , 17.v.2014, N. Kawase; 3 males, 1 male pupa, Akebibara, Tsuchiyama-cho, Koka-shi , 15.v.1989, T. Nozaki ( KPM); 5 males, 1 female, Okawara, Tsuchiyama-cho, Koka-shi , 14–30.v.2008, N. Kawase ( NK); 2 males, 1 female, Buhei-toge, Okawara, Tsuchiyama-cho, Koka-shi , 13.v.2008, N. Kawase ( NK); 2 males, Shirokura-dani, Okawara, Tsuchiyama-cho, Koka-shi , 17.v.2005, N. Kawase ( NK); 1 male, 1 female, same locality, 30.iv.2007, N. Kawase ( NK); 40 males, 45 females, Yuzurio, Eigenji-cho, Higashiomi-shi , 12–31.v.2009, N. Kawase ( NK); 1 male, same locality, 12.v.2009, N. Kawase ( NK); 4 males, Oishitomikawa-cho, Otsu-shi , 22.iv–16.v.2024, N. Kawase ( NK). Hyogo: 3males, 1 female, Soryu-no-taki, Santocho-kawakami, Asago-shi , 15.v.2015, K. Inazu ( KI); 1 male, 2 females, Hyono-senrindo, alt. 911 m, Unawa, Sekimiya-cho, Yabu-shi , 2.vi.2007, K. Inazu ( KI); 2 males, 1 female, same locality, 30.v.2022, K. Inazu; 1 male, seep, alt 965 m, Oyacho-yokoiki, Yabu-shi , 18.v.2023, K. Inazu ( KI); 2 females, same locality, 28.vi.2023, K. Inazu ( KI); 2 males, 2 females, Ichinomiyacho-sencho, Shiso-shi , alt. 800–900 m, 6.vi.2016, K. Inazu (1 male, 1 female: KI); 3 males, 1 female, Arinocho-karato, Kita-ku, Kobe-shi , 12.v.2020, S. Watanabe ( MNHA). Okayama: 1 male, Ogaya, Nishiawakura-son , 28.v.2017, K. Nojima ( KN); 9 males, 2 females, Ombara, Kamisaibara, Kagamino-cho , 23.v.2021, K. Nojima (6 males, 1 female: KN).

Distribution. Honshu (central to western).

Biology. Larvae of this species were collected from small spring flows or seeps in mountain areas. Adults were active in the daytime of late spring to early summer, and Watanabe (2021) reported a diurnal mating behavior.

Japanese name. Nagae-kimadara-shima-tobikera.

Remarks. Descriptions of male and female genitalia above are based on 17 males and 15 females collected using a Malaise trap in Moroka, Sakauchi-sakamoto, Ibigawa-cho, Gifu Prefecture. These females have genitalia similar to those of the holotype female ( Nozaki 2021, fig. 6C). Ulmer (1907) described this species as a member of the genus Diplectrona based on a female specimen, and Nozaki (2021) transferred it to the genus Homoplectra based on the examination of photographs of the holotype.

Nozaki (2021) mistakenly wrote that the holotype female was collected from “an unknown locality in Gifu, central Honshu”; but in fact, Ulmer (1907) did not mention the precise name of the type locality other than “ Japan.” Although the type locality of this species is not known, females which have similar genital morphology as those of the holotype were found in specimens collected from western Gifu and adjacent areas in central Honshu in this study ( Fig. 4I View FIGURE 4 and Nozaki 2021, fig. 6E).

In addition, Ulmer (1907) recorded males collected from Gifu as Diplectrona japonica [= H. japonica ]; however, the male of H. japonica described above does not have a pair of long spine-like processes arising from the genital chamber as described and illustrated by Ulmer (1907, figs 114–115). According to Ulmer’s description, his male bears a tooth-like projection (eine zahnartige Erhebung) on the subapicomesal face of each inferior appendage. These characters suggest that his specimen must belong to H. albomarginata .

The male and female genitalia of H. albomarginata are very variable ( Figs 4 View FIGURE 4 , 5 View FIGURE 5 ). Although I treat them as individual and/or geographic variations in the single species H. albomariginata , further study with molecular data is needed to confirm their identity and phylogenetic relationships.