Homoplectra shikoku Nozaki, 2025, sp. nov.
Creators: name: Nozaki, Takao
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Trichoptera
Hydropsychidae
Homoplectra
Homoplectra shikoku

description: Homoplectra shikoku sp. nov.
(Figs 7, 13)
“ Diplectrona ” japonica Complex: Yamamoto & Ito 2014, p. 13.
Diplectroninae Gen. japonica Species Complex: Nozaki 2016, pp 75, 348, female (photo); Yamamoto et al. 2021, p. 73.
Diagnosis. The male of this species is somewhat similar to those of H. japonica and H. flagelliformis sp. nov. in having a short antennal scape and in the shape of the phallic apparatus; but is easily distinguishable from those two species by bearing long inner processes of the genital chamber and posterior processes of segment X (Fig. 7C).
The female of this species is similar to that of H. flagelliformis sp. nov. in having a trapezoidal basoventral lobe on the vulvar scale, but they can be distinguished from each other by the character states given in the diagnosis for that species.
Description
Adult (Fig. 7A). General coloration of body and wings, and length of antennal scapes similar to those of H. japonica. Yellow markings on female wings rarely lacking. Forewings each 9.0–11.0 mm in male (n = 10), 9.8–13.0 mm in female (n = 10), 9.5 mm in male holotype.
Male genitalia (Figs 7C–7H). Ventrolateral sides of synsclerotized segment IX subtriangular in lateral aspect (Fig. 7C); posteroventral lobe trapezoidal in ventral aspect (Fig. 7E), usually with central shallow notch apically; dorsal part of segment IX triangular with round apex in dorsal aspect (Fig. 7D), broadly fused with segment X laterally (Fig. 7C). Segment X bilobed in dorsal aspect (Fig. 7D), pair of posterolateral setose areas thumb-like in lateral aspect (Fig. 7C); each with ventrolateral margin sclerotized; segment X with pair of posterior processes (p.p.X) having variable length, even in same locality (Figs 7H1–7H3), with few apical spine-like setae. Genital chamber with pair of weakly sclerotized lateral strips (l.s.); with pair of long spine-like inner processes (i.p.) evenly curved ventrad (Fig. 7C). Inferior appendages each without distal segment, long finger-like in lateral aspect (Fig. 7C), extending beyond apex of segment X, weakly bent upward in apical 1/3; subapicomesal apex weakly bulging mesally and with more than 10 spine-like setae (Figs 7C inset, 7D, 7E). Phallic apparatus arcuate in lateral aspect (Fig. 7F), dorsal process of phallotheca acicular in lateral and dorsal aspects (Figs 7F, 7G), gently curved ventrad (Fig. 7F); pair of ventral processes of phallotheca approximately 2/3 as long as dorsal process (Fig. 7F), but occasionally only slightly shorter than dorsal process. Aedeagal stem thick, half-pipe-like (Fig. 7G), moderately curved ventrad, with long head, approximately 1/4 as long as basal stem (Fig. 7F).
Female genitalia (Figs 7I–7K). Lateral lobes of sternum VIII cleft from base, mesal margins convex, posteromesal margin evenly curved laterad in ventral aspect (Fig. 7K). Segment IX subrectangular with round posterolateral corners in dorsal aspect (Fig. 7J), obliquely S-shaped in lateral aspect (Fig. 7I); pair of mesal lobes sclerotized, semicircular in lateral aspect (Fig. 7I); pair of sclerotized ribs forming wide trapezoidal lobes on vulvar scale basoventrally (Fig. 7K). Vulvar scale tongue-like in ventral aspect, membranous apically (Fig. 7K). Vaginal apparatus long triangular in dorsal aspect (Fig. 7J); with pair of sclerotized round bulges posterolaterally, and with dark M-shaped mark between pair of longitudinal ridges anteriorly, partially surrounding opening of duct of spermatheca.
Immature stages. Unknown.
Holotype. Male (in alcohol): Izugataniyama, Nishidani, Kumakogen-cho, Ehime, 33.5628°N, 132.9358°E, alt. 1370 m, 20.v.2020, E. Yamamoto (KPM-NK TN00610).
Paratypes. 15 males, 8 females, same data as holotype (KPM-NK TN00620, KPM-NK TN00630), 2 males (pinned), Nishidani, Kumakogen-cho, Ehime, alt. 1310 m, 25.v.2011, T. Hattori (SPMN-IS- 59802, SPMN-IS- 59803).
Other specimens examined. JAPAN: SHIKOKU: Tokushima: 6 males, 5 females, Konose-kyo, Kitokitagawa, Naka-cho, 6.v.2009, T. Torii (SPMN); 1 male, Higashiiya-sugeoi, Miyoshi-shi, alt. 1330–1380 m, 8.vi.2011, T. Nozaki (KPM). Ehime: 7 males, 4 females, type locality, 11.v–10.vi.2013, E. Yamamoto; 10 males, type locality, 21–31.v.2018, E. Yamamoto; 1 male, Yurano-mori, Kumakogen-cho, 10.v.2007, E. Yamamoto; 4 males, same, 21.v.2007, E. Yamamoto; 1 male, Tsuchigoya, Wakayama, Kumakogen-cho, 20.vii.1996, T. Befu (KPM); 2 males, Wakayama, Kumakogen-cho, 21.v.1999, A. Ohkawa & T. Ito; 1 males, Banjo-dani, Wakayama, Kumakogen-cho, 9.vi.2011, K. Nio (KPM); 2 males, 2 females, Mt. Kasatori, Uchiko-cho, alt. 1500 m, 6–10.vi.2013, E. Yamamoto; 1 male, same, 16–20.vi.2020, E. Yamamoto; 4 males, Oda-cho, Uchiko-cho, 8.v.1992, E. Yamamoto (KPM); 4 males, Odamiyama, Uchiko-cho, 4.v.1986, E.Yamamaoto (KPM); 2 males, same locality, 28.iv.1990, E. Yamamoto (KPM); 2 males, same locality, 20.v.1991, E. Yamamoto (KPM); 1 male, same locality, 13.v.2002, E. Yamamoto (KPM); 32 males, 6 females, Namakusa-dani, Odamiyama, Uchiko-cho, 23.v.2020, E. Yamamoto; 12 males, 7 females, Hondani, Odamiyama, Uchiko-cho, 17.v.2020, E. Yamamoto; 13 males, 3 females, Koya-yama, Odamiyama, Uchiko-cho, 21.v.2020, E. Yamamoto; 5 males, 3 females, Honomata, Odamiyama, Uchiko-cho, alt. 925 m, 1–20.v.2018, E. Yamamoto. Kochi: 1 male, Nishikuma-rindo, Monobe-cho, Kami-shi, 20.vi.1999, T. Befu (KPM); 3 males, 1 female, same, 12.v.2001, M. Takai; 1 female, same, 5.v.2004, M. Takai; 1 male, Shiraga-toge, Monobe-cho, Kami-shi, 3.vii.2004, T. Takai; 1 male, Befu-kyo, Monobe-cho, Kami-shi, 5.v.2002, M. Takai; 1 female, Tengu-ike, Tsuno-cho, 11.v.2002, M. Takai; 1 male, 1 female, Funato, Tsuno-cho, alt. 910 m, 24.v.2011, T. Hattori (SPMN); 6 males, 2 females, Nano-gawa, Terakawa, Ino-cho, 25.v.1999, A. Ohkawa & T. Ito; 1 male, Mt. Iyofuji, Nakanoka, Ino-cho, alt. 1540 m, 9.vi.2011, T. Nozaki & K. Nio; 1 male, Kuroson, Nishitosa, Shimanto-shi, 30.iv.2005, M. Takai.
Etymology. The specific epithet refers to a major island in Japan, named Shikoku, where this species is widely distributed.
Distribution. Shikoku.
Biology. Many adults of this species, including a mating pair, were found resting on leaves of vegetation along spring seeps or small flows at the type locality in the daytime on 20 May 2020 (Figs 7A, 7B), and were easily collected with an insect net (Yamamoto personal communication on 13 July 2024).
Japanese name. Shikoku-kimadara-shima-tobikera
description: Published as part of Nozaki, Takao, 2025, Redescriptions of Homoplectra japonica (Banks 1906) and H. albomarginata (Ulmer 1907) (Trichoptera, Hydropsychidae), with descriptions of five new similar species from Japan, pp. 303-328 in Zootaxa 5566 (2) on pages 316-318, DOI: 10.11646/zootaxa.5566.2.4, http://zenodo.org/record/14702954