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

description: Homoplectra bicornis sp. nov.
(Fig. 8, 13)
Diagnosis. The male of this species is easily distinguishable from those of other congeneric Japanese species by the pair of posterodorsal horn-like lobes of the segment IX (Fig. 8B). The female is also easily distinguishable from those of known Japanese species by the bottle-like sclerotization of the ventral side of segment X (Fig. 8H).
Description
Adult. General morphology and coloration similar to those of Homoplectra japonica, yellow markings on female wings often indistinct. Forewings each 6.0–9.0 mm long in male (n = 10), 7.5–10.0 mm long in female (n = 3), 7.2 mm in male holotype.
Male genitalia (8A–8E). Ventrolateral sides of synsclerotized segment IX with triangular anterior projection in lateral aspect (Fig. 8A); posteroventral lobe triangular and tiny or lacking (Fig. 8C); dorsal part of segment IX rectangular in dorsal aspect (Fig. 8B), with pair of straight, horn-like lobes posterolaterally; broadly fused with segment X laterally (Fig. 8A). Segment X tapering to acute apex in dorsal aspect (Fig. 8B), bilobed posteriorly; pair of posterolateral setose areas protruding posteriorly (Fig. 8A); pair of posterior processes of segment X (p.p.X) long, spine-like, directed posterodorsad, each fused with lateral strip of genital chamber (l.s.) near posteroventral corner of segment X (Fig. 8A). Genital chamber with pair of sclerotized lateral strips curved dorsad near posteroventral corner of segment X (Fig. 8A); pair of inner processes (i.p.) long, spine-like, each arising from near anterior part of lateral strip, slightly curved ventrad, approximately as long as posterior processes of segment X (Fig. 8A). Inferior appendages each without distal segment, slightly clavate in lateral aspect (Fig. 8A), extending slightly beyond apex of segment X; each weakly convex subapicomesally, with 5–10 spine-like setae (Figs 8A inset, 8B, 8C). Phallic apparatus arcuate in lateral aspect (Fig. 8D); dorsal process of phallotheca long and narrowly triangular in dorsal aspect (Fig. 8E); pair of lateral processes of phallotheca 1/5 as long as dorsal process, usually acute apically (Fig. 8D) but rarely blunt; pair of ventral processes longer than dorsal process, each with apical half weakly sinuated in dorsal aspect (Fig. 8E). Aedeagal stem half-pipe-like, moderately curved ventrad; head about 1/7 as long as stem (Figs 8D, 8E).
Geographic variation of male genitalia (Fig. 8F). In males collected from Yamanashi Prefecture, each horn-like posterolateral lobe of segment IX in dorsal aspect is apically round and directed mesad (Fig. 8F).
Female genitalia (Fig. 8G–8H). Lateral lobes of sternum VIII cleft from base (Fig. 8I). Segment IX obliquely rectangular in lateral aspect (Fig. 8G), subpentagonal posteriorly in dorsal aspect (Fig. 8H), tergum widely sclerotized ventrally; each mesal lobe sclerotized, bean-shaped in lateral aspect (Fig. 8G), forming large crevice between it and segment IX; with pair of sclerotized ribs on vulvar scale basolaterally in ventral aspect (Fig. 8I), weakly ridged near anteromesal margins. Vulvar scale large, membranous apically (Fig. 8I). Segment X setose, subrectangular, longitudinally short in lateral aspect (Fig. 8G); ventral side sclerotized, with shape of large bottle in dorsal aspect (marked with an arrow in Fig. 8H). Vaginal apparatus slender pentagonal in dorsal aspect (Fig. 8H), with pair of falcate sclerites posterodorsally, with pair of dorsal longitudinal ridges, and with dark arch mark between ridges anterodorsally, mostly surrounding opening of duct of spermatheca (Fig. 8H).
Immature stages. Unknown.
Holotype. Male (pinned): Nyujima, Aoi-ku, Shizuoka-shi, Shizuoka, 35.2270°N, 138.3456°E, alt. 400 m, 5.v.2006, T. Nozaki (KPM-NK 91358).
Paratypes. 1 male (pinned), same data as holotype (KPM-NK 91359); 8 males, 1 female (in alcohol), same locality as holotype, 11.v.1997, T. Hattori (KPM-NK TN00640, KPM-NKTN00650); 6 males, 1 female (pinned), same locality as holotype, 3.v.2002, T, Hattori (SPMN-IS-59804–59810).
Other specimens examined. JAPAN: HONSHU: Yamanashi: 4 males, Heisei-kyo, Takao, Minami-alpsshi, alt. 1200–1400 m, 6.vii.1997, T. Hattori (SPMN); 1 female, Oyana-gawa, Fujikawa-cho, 9.vi.1996, T. Hattori (SPMN). Shizuoka: 8 males, 1 female, same locality as holotype, 5.v.1997, T. Hattori (SPMN); 1 male, same locality as holotype, 5.v.1995, T. Hattori (SPMN); 7 males, 1 female, same locality as holotype, 11.v.1997, T. Hattori; 1 male, same locality as holotype, 9.v.2006, T. Torii (TT); 2 males, 1 female, Utogi, alt. ca. 700 m, Aoi-ku, Shizuoka-shi (SPMN); 1 male, Kamikouchi-zawa, alt. 1000 m, Aoi-ku, Shizuoka-shi, 6.v.1990, T. Hattori (SPMN); 1 male, same locality, 20.vi.1990, T. Hattori (SPMN); 1 male, same locality, 9.vi.1991, T. Hattori (SPMN); 7 males, 1 female, Hatanagi, Aoi-ku, Shizuoka-shi, 18.vi.1989, T. Hattori (SPMN); 2 males, 3 females, same locality, 20.vi.1990, T. Hattori (SPMN); 1 male, 2 females, Mitsumine, Yokosawa, Aoi-ku, Shizuoka-shi, 27.v.2004, T. Hattori (SPMN); 1 male, Nigori-gawa, alt. 650 m; Umegashima, Aoi-ku, Shizuoka-shi, T. Hattori (SPMN); 1 male, Nishi-hikage-sawa, Umegashima, Aoi-ku, Shizuoka, 16.vii.1995, T. Hattori (SPMN); 1 male, 2 females, Ushikubi-toge, alt. 1500 m, Umegashima, Aoi-ku, Shizuoka-shi, 25.vii. 1998, T. Hattori (SPMN); 2 females, Abe-toge, Umegashima, Aoi-ku, Shizuoka-shi, 16.vii.1995, T. Hattori (SPMN).
Etymology. The species epithet (Latin adjective, two-horned) refers to the pair of horn-like posterolateral projections of the male segment IX in dorsal aspect.
Distribution. Central Honshu.
Biology. The holotype and a paratype male of this species were flying in the day time around a small waterfall at the type locality.
Japanese name. Tsuno-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 318-320, DOI: 10.11646/zootaxa.5566.2.4, http://zenodo.org/record/14702954