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

description: Homoplectra flagelliformis sp. nov.
(Figs 6, 13)
Diplectrona japonica nec Banks 1906: Kawase & Hayashi 2010, p. 85. Misidentification.
Diplectroninae Gen. japonica Species Complex: Nojima 2017 (in part), p. 119.
Diagnosis. The male of this species is very similar to that of H. japonica in the short antennal scapes and the shape of the phallic apparatus; but can be distinguished by the shape of the ventral processes of the phallotheca and aedeagus: In this species, the ventral processes of the phallotheca are almost straight apically (Figs 6D, 6H), and the stem of the aedeagus bears a pair of round lobes apically in lateral aspect (Fig. 6D); but in H. japonica, the ventral processes of phallotheca curve dotsomesad apically (Figs 3D, 3E), and the posterior margin of the aedeagal stem is truncate in lateral aspect (Fig. 3D).
The female of this species is similar to that of Homoplectra shikoku sp. nov., in having a trapezoidal basoventral lobe on the vulvar scale but these species can be easily distinguished from each other by the shape of the lateral lobes of segment VIII: The mesal margin of each lateral lobe is concave in the middle in this species (Fig. 6K), but it is smoothly convex in H. shikoku sp. nov. (Fig. 7K).
Description
Adult. Length of antennal scape and general coloration of body and wings very similar to those of H. japonica. Wings occasionally uniformly dark brown in female. Forewings each 8.5–10 mm in male (n = 10), 10.5–13 mm in female (n = 10), 9.7 mm in male holotype.
Male genitalia (Figs 6A–6H). Ventrolateral sides of synsclerotized segment IX protruding anterad and round on each side in lateral aspect (Fig. 6A); posteroventral lobe long and rectangular in ventral aspect (Fig. 6C), its apex weakly bilobed in ventral aspect. Dorsal part of segment IX subtriangular, apically round in dorsal aspect (Fig. 6B), fused with segment X laterally (Fig. 6A). Segment X bilobed in dorsal aspect (Fig. 6B), with pair of large posterolateral setose areas (Fig. 6A); each ventrolateral margin sclerotized, recessed into segment IX (Fig. 6A). Inferior appendages each without distal segment, long and finger-like in lateral aspect (Fig. 6A), extending beyond apex of segment X, slightly curved upward apically; slightly convex subapicomesally, with about 10 spine-like setae (Figs 6A–6C). In phallotheca, long dorsal process thin, whip-like in lateral aspect (Fig. 6D), gradually curving posteroventrad (specimens macerated by KOH solution often strongly curved or recurved apically as in Fig. 6F); broad basally and tapering to acute apex in dorsal aspect (Fig. 6E); lateral processes absent; pair of ventral processes in lateral and dorsal aspect (Figs 6D–6F) slender, almost straight, approximately half as long as dorsal process. Aedeagus evenly curved ventrad in lateral aspect (Fig. 6D); stem half-pipe-like, with pair of posterior lobes, each lobe oval in lateral aspect (Figs 6D) and concave mesally (Fig. 6E); with head approximately 1/4 as long as basal stem (Fig. 6D).
Female genitalia (Figs 6I–6L). Lateral lobes of sternum VIII widely separated from each other in ventral aspect (Fig. 6K), each with mesal margin concave in middle. Segment IX oblique rectangular in lateral aspect (Fig. 6I), subpentagonal with round lateral and apical margins in dorsal aspect (Fig. 6J); pair of mesal lobes sclerotized, semicircular in lateral aspect (Fig. 6I); pair of sclerotized ribs forming wide trapezoidal lobe on vulvar scale basoventrally (Fig. 6K). Vulvar scale large, membranous and convex apically. Vaginal apparatus long pentagonal in dorsal aspect (Fig. 6J), tapering to duct of bursa copulatrix; posterodorsal part semimembranous, with complicated wrinkles, with pair of longitudinal ridges dorsally, opening of duct of spermatheca situated between ridges near middle, with dark inverted V-shaped mark dorsally, partially surrounding opening of duct of spermatheca (Fig. 6J).
Geographic variations of male and female genitalia (Figs 6G, 6H, 6L). In males collected from Okayama and Hiroshima Prefectures, the posteroventral lobe of segment IX is short (Fig. 6G). The ventral processes of the phallotheca are approximately the same length as the dorsal process of the phallotheca in specimens collected from Hiroshima Prefecture (Fig. 6H). In females collected from Hiroshima Prefecture, the posterior margin of basoventral lobe on the vulvar scale is shallowly concave (Fig. 6L).
Immature stages. Unknown.
Holotype. Male (in alcohol): Takezaki, Okuizumo-cho, Shimane, 35.1693°N, 133.1751°E, alt. 761 m, 16– 28.v.2007, M. Hayashi, Malaise trap (KPM-NK TN00580).
Paratypes. 10 males, 5 females (in alcohol), same data as holotype (KPM-NK TN00590, KPM-NK TN00600).
Other specimens examined. JAPAN: HONSHU: Tottori: 1 male, 2 females, Funadani-gawa, Kofu-cho, alt. 750 m, 25.v.1993, N. Kuhara (KuN). Shimane: 25 males, 12 females, same data as holotype (20 males, 7 females: NK). Okayama: 5 males, 1 female, Oosaooino, Niimi-shi, 8.v.2016, K. Nojima (KN); 3 males, 1 female, Hiruzenkamifukuda, Maniwa-shi, 5.v.2016 (KN). Hiroshima: 1 male, 2 females, Yoshiwa, Hatsukaichi-shi, 11.v.1976, K. Baba (KPM); 3 males, Hosomi-dani, Yoshiwa, Hatsukaichi-shi, 11.v.2005, I. Mori.
Etymology. The species epithet (Latin adjective, whip-like) refers to the whip-like dorsal process of the phallotheca.
Distribution. Western Honshu (Chugoku District).
Biology. Many adults of this species were collected in May using a Malaise trap over a small spring flow at the type locality (Kawase and Hayashi 2010).
Japanese name. Muchio-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 314-316, DOI: 10.11646/zootaxa.5566.2.4, http://zenodo.org/record/14702954