Homoplectra bicornis, Nozaki, 2025

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, Zootaxa 5566 (2), pp. 303-328 : 318-320

publication ID	https://doi.org/10.11646/zootaxa.5566.2.4
publication LSID	lsid:zoobank.org:pub:9866D791-F9AA-4701-9EBC-B3A52613C657
DOI	https://doi.org/10.5281/zenodo.14718632
persistent identifier	https://treatment.plazi.org/id/03BD87A8-3111-FF80-FF2D-BFE5D2DA242D
treatment provided by	Plazi
scientific name	Homoplectra bicornis
status	sp. nov.

Treatment

Homoplectra bicornis sp. nov.

( Fig. 8 View FIGURE 8 , 13 View FIGURE 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 View FIGURE 8 ). 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 View FIGURE 8 ).

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 View FIGURE 8 ); posteroventral lobe triangular and tiny or lacking ( Fig. 8C View FIGURE 8 ); dorsal part of segment IX rectangular in dorsal aspect ( Fig. 8B View FIGURE 8 ), with pair of straight, horn-like lobes posterolaterally; broadly fused with segment X laterally ( Fig. 8A View FIGURE 8 ). Segment X tapering to acute apex in dorsal aspect ( Fig. 8B View FIGURE 8 ), bilobed posteriorly; pair of posterolateral setose areas protruding posteriorly ( Fig. 8A View FIGURE 8 ); 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 View FIGURE 8 ). Genital chamber with pair of sclerotized lateral strips curved dorsad near posteroventral corner of segment X ( Fig. 8A View FIGURE 8 ); 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 View FIGURE 8 ). Inferior appendages each without distal segment, slightly clavate in lateral aspect ( Fig. 8A View FIGURE 8 ), extending slightly beyond apex of segment X; each weakly convex subapicomesally, with 5–10 spine-like setae ( Figs 8A View FIGURE 8 inset, 8B, 8C). Phallic apparatus arcuate in lateral aspect ( Fig. 8D View FIGURE 8 ); dorsal process of phallotheca long and narrowly triangular in dorsal aspect ( Fig. 8E View FIGURE 8 ); pair of lateral processes of phallotheca 1/5 as long as dorsal process, usually acute apically ( Fig. 8D View FIGURE 8 ) but rarely blunt; pair of ventral processes longer than dorsal process, each with apical half weakly sinuated in dorsal aspect ( Fig. 8E View FIGURE 8 ). Aedeagal stem half-pipe-like, moderately curved ventrad; head about 1/7 as long as stem ( Figs 8D, 8E View FIGURE 8 ).

Geographic variation of male genitalia ( Fig. 8F View FIGURE 8 ). 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 View FIGURE 8 ).

Female genitalia ( Fig. 8G–8H View FIGURE 8 ). Lateral lobes of sternum VIII cleft from base ( Fig. 8I View FIGURE 8 ). Segment IX obliquely rectangular in lateral aspect ( Fig. 8G View FIGURE 8 ), subpentagonal posteriorly in dorsal aspect ( Fig. 8H View FIGURE 8 ), tergum widely sclerotized ventrally; each mesal lobe sclerotized, bean-shaped in lateral aspect ( Fig. 8G View FIGURE 8 ), forming large crevice between it and segment IX; with pair of sclerotized ribs on vulvar scale basolaterally in ventral aspect ( Fig. 8I View FIGURE 8 ), weakly ridged near anteromesal margins. Vulvar scale large, membranous apically ( Fig. 8I View FIGURE 8 ). Segment X setose, subrectangular, longitudinally short in lateral aspect ( Fig. 8G View FIGURE 8 ); ventral side sclerotized, with shape of large bottle in dorsal aspect (marked with an arrow in Fig. 8H View FIGURE 8 ). Vaginal apparatus slender pentagonal in dorsal aspect ( Fig. 8H View FIGURE 8 ), 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 View FIGURE 8 ).

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 ). GoogleMaps

Paratypes. 1 male (pinned), same data as holotype ( KPM-NK 91359 ) GoogleMaps ; 8 males, 1 female (in alcohol), same locality as holotype, 11.v.1997, T. Hattori ( KPM-NK TN00640 , KPM-NKTN00650 ) GoogleMaps ; 6 males, 1 female (pinned), same locality as holotype, 3.v.2002, T, Hattori (SPMN-IS-59804–59810). GoogleMaps

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 GoogleMaps , 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 GoogleMaps , 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 GoogleMaps , 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 GoogleMaps , Aoi-ku, Shizuoka-shi, 27.v.2004, T. Hattori ( SPMN); 1 male, Nigori-gawa GoogleMaps , alt. 650 m; Umegashima, Aoi-ku, Shizuoka-shi, T. Hattori ( SPMN); 1 male, Nishi-hikage-sawa, Umegashima, Aoi-ku GoogleMaps , Shizuoka, 16.vii.1995, T. Hattori ( SPMN); 1 male, 2 females, Ushikubi-toge GoogleMaps , alt. 1500 m, Umegashima, Aoi-ku, Shizuoka-shi, 25.vii. 1998, T. Hattori ( SPMN); 2 females, Abe-toge, Umegashima GoogleMaps , 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.