taxonID	type	description	language	source
C97B87ACFFA5FF8EFF77FC645B8DF98B.taxon	description	(Figs 1 A, 1 B, 2 A – 2 H, 3 A – 3 E, 16 C) Rhyacophila sp. 15: Yamamoto et al. 2021, 70, list.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA5FF8EFF77FC645B8DF98B.taxon	diagnosis	Diagnosis. Male and female genitalia of this species are very distinctive among the R. retracta Species Group. The male genitalia are distinguishable from those of other species by the following two remarkable characters: The apicodorsal lobe of segment IX bears two pairs of stout and acute projections and segment X curves sharply posteroventrally (Figs 2 A, 2 C). In females, a pair of lateral clefts of segment VIII are situated rather ventrally and these clefts can be seen in ventral view (Fig. 3 C). Moreover, the apical half of the posterior process of the vaginal apparatus is acicular in this species (Figs 3 D, 3 E). Adult (Figs 1 A, 1 B). Length of each forewing: male 9.0 – 11.4 mm (mean = 10.4, SD = 0.70, n = 20), female 9.5 – 13.5 mm (mean = 11.9, SD = 0.94, n = 16). Forewings pale yellowish brown in male, yellowish brown in female, with irregular brown reticulation as in Figs 1 A, 1 B; assembly of rather clear pale patches at middle of hind margin in male and female (Figs 1 A, 1 B). Abdomen with small midventral process on posterior margin of sternites VI and VII in male, on that of sternite VI in female.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA5FF8EFF77FC645B8DF98B.taxon	description	Male genitalia (Figs 2 A – 2 H). Segment IX (IX) very short ventrally and long dorsally in lateral view (Fig. 2 C), rectangular in dorsal view (Fig. 2 A). Apicodorsal lobe (adl) large, widely spread and covered basal part of segment X, with two pairs of acute, finger-like projections, middle pair longer than lateral one (Figs 2 A, 2 C). Segment X (X) long, extending posteroventrad, bend 90 degrees in middle, like crane neck in lateral view (Fig. 2 E); with pair of dorsolateral ridges forming longitudinal deep groove, ridges bearing raw of setae (Fig. 2 F); apex dark pigmented, with median incision, each posterolateral process (plp) slightly expanded posterolaterad (Fig. 2 F). Pair of anal sclerites (as) fused together, bean shaped in ventral view, dark pigmented, with long common root (Figs 2 E – 2 G). Apical band (ab) sclerotized, u-shaped in ventral view, and fused with tergal band basally; tergal band (tb) well sclerotized apically, connecting to dorsum of phallotheca (pht) anteriorly (Fig. 2 E). Basal segment of each inferior appendage (bsia) setose, elongate, basal half slightly thicker in lateral view (Figs 2 C, 2 D). Apical segment of each inferior appendage (asia) subtriangular, posterodorsal margin weakly concaved in lateral view (Figs 2 C, 2 D), bearing spinules mesally (Fig. 2 D). In phallic apparatus, phallotheca cup-shaped in lateral view (Fig. 2 E); aedeagus (aed) long, almost cylindrical tapering to apex (Figs 2 B, 2 E, 2 H); dorsal appendage of phallic apparatus (dap) sclerotized, slightly shorter than aedeagus, basal 3 / 4 fused with aedeagus, apex truncated in dorsal view (Figs 2 E, 2 H). Pair of parameres (par) long, basal half thick in lateral view (Fig. 2 E), apical half thin, directed posterodorsad with acute apex (Figs 2 B, 2 E). Female genitalia (Figs 3 A – 3 E). Segment VIII (VIII) with dorsal cleft (dc) extremely wide and deep, reaching approximately 2 / 3 of segment in dorsal view (Fig. 3 A); with pair of deep lateral clefts (lc) lateroventrally, each extending to middle part of segment (Figs 3 B, 3 C); pair of apodemal rods (ar) slightly longer than segment VIII in lateral view (Fig. 3 B). Intersegmental membrane of segment VIII – X (ismVIII – X) deeply invaginated into segment VIII, slightly sclerotized, anterior part fixed to interior wall of segment VIII (Figs 3 A – 3 C). In vaginal apparatus, posterior process (pp) long, sclerotized, apical half extremely thin (Figs 3 D, 3 E), basal half thick, subtriangular in lateral view, slightly curved anteroventrad (Fig. 3 D); processus spermathecae (ps) small, subrectangular in lateral view, covered by basal part of posterior process (Fig. 3 D). Immature stage. Unknown.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA5FF8EFF77FC645B8DF98B.taxon	materials_examined	Holotype. Male (in alcohol): Namakusa-dani, Odamiyama, Uchiko-cho, Ehime Prefecture, Shikoku, Japan, 33 ° 33 ’ 37 ” N 132 ° 55 ’ 04 ” E, alt. 1225 m, 11 – 20. vi. 2020, E. Yamamoto (LBM 1410012659). Paratypes. Shikoku: Ehime: 1 female (pinned), Yonaru-kawa, Yanaigawa, Kuma-kôgen-cho, 25. v. 2011, T. Hattori (SPMN); 1 female, same data as the holotype (LBM 1410012660); 2 males, 4 females, type locality, 21. vi. 1999, E. Yamamoto (SPMN); 6 males, 3 females, type locality, 5. vi. 2000, E. Yamamoto (SPMN); 1 female, type locality, 8. viii. 2000, E. Yamamoto (SPMN); 2 males, 1 female, type locality, 20. ix. 2000, E. Yamamoto (SPMN); 1 female, Honomata, Odamiyama, Uchiko-cho, 1 – 10. vi. 2018, E. Yamamoto (LBM 1410012661); 1 male, same locality, 11 – 20. vi. 2018, E. Yamamoto (LBM 1410012662); 1 male (pinned, fig. 1 A), 1 female (pinned, fig. 1 B), Mitaki-keikoku, Kubono, Shirokawa-cho, Seiyo-shi, 22. v. 2011, T. Hattori (SPMN). Other specimens examined. Shikoku: Ehime: 2 females, Kanmon, Omogo, Kuma-kôgen-cho, 23 – 25. v. 1999, A. Ohkawa & T. Ito (SPMN); 4 males, 6 females, same data as the holotype, 11 – 20. vi. 2020, E. Yamamoto (Nka); 1 male, Hontani, Odamiyama, Uchiko-cho, 5 – 8. v. 2000, E. Yamamoto (SPMN); 1 female, same locality, 19. v. 2000, E. Yamamoto (SPMN); 1 female, Tarôdani, Odamiyama, Uchiko-cho, 20. vi. 2000, E. Yamamoto (SPMN). Kochi: 1 male, Sakihama-gawa, Muroto-shi, 29. iv. 2004, M. Takai (SPMN); 2 males, Ioki-gawa, Bettyaku, Aki-shi, 25. iv. 2004, K. Nio (SPMN); 1 female, Nishikuma-keikoku, Kubo-wakubo, Monobe-cho, Kami-shi, 25. vi. 2003, K. Nio (SPMN); 1 male, Befu-kyo, Monobe-cho, Kami-shi, 28. v. 2004, M. Takai (SPMN).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA5FF8EFF77FC645B8DF98B.taxon	distribution	Distribution and biology. Rhyacophila geranos sp. nov. is distributed only in Shikoku, one of Japanese main islands (Fig. 16 C). The adults were collected near mountain streams in late April to September by sweeping, Malaise traps or light traps.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA5FF8EFF77FC645B8DF98B.taxon	etymology	Etymology. The species epithet “ geranos ” (= crane) is a Greek noun derived from the crane neck-like segment X in lateral view, and crane wing-like apicodorsal lobe of segment IX in dorsal view. Japanese name. Tsuruo-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA0FF8DFF77F92C5B83F9D3.taxon	description	(Figs 1 C, 1 D, 4 A – 4 G, 5 A – 5 E, 16 D)	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA0FF8DFF77F92C5B83F9D3.taxon	diagnosis	Diagnosis. The male genitalia of R. humerigera sp. nov. are somewhat similar to those of R. koryne sp. nov., R. motakanta and R. orthacantha in having the apically bifid apicodorsal lobe of segment IX. The difference is, however, considerable. R. humerigera sp. nov. bears a pair of lateral shoulders in the middle of the apicodorsal lobe (Figs 4 A, 4 Aa), whereas other three species bear the simple, short apicodorsal lobe without such a pair of shoulders. Regarding the female genitalia, R. humerigera sp. nov. is similar to R. motakanta Schmid 1970 and R. lambakanta Schmid 1970 in bearing a medium-sized dorsal and a pair of lateral clefts in segment VIII (Figs 5 A – 5 C, 13 A – 13 B, 14 A – 14 B), but this species can be distinguished from the latter by the shape of the posterior processes of the vaginal apparatus: In R. humerigera, the apical part of the posterior process is simply round (Figs 5 D, 5 E), but in R. motakanta, the apical part of that decreases abruptly in width and height (arrows in figs 13 C, 13 D); in R. humerigera, the vaginal apparatus bends approximately 45 degrees in lateral view (Fig. 5 D), but in R. lambakanta, it bends 90 degrees in the middle in lateral view (arrows in fig. 14 D). Adult (Figs 1 C, 1 D). Length of each forewing: male 8.2 – 10.4 mm (mean = 9.3, SD = 0.77, n = 14), female 10.0 – 11.3 mm (mean = 10.7, SD = 0.50, n = 5). General morphology of R. humerigera sp. nov. similar to those of R. geranos sp. nov., but forewings of this species with many brown reticulations all over (Figs 1 C, 1 D). In abdomen, small mid ventral process on posterior margin of sternites VI and VII in male, on that of sternite VI in female.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA0FF8DFF77F92C5B83F9D3.taxon	description	Male genitalia (Figs 4 A – 4 G). Segment IX (IX) in lateral view, very short ventrally, long dorsally, widely rounded posterolaterally (Fig. 4 C); subquadrate in dorsal view, with pair of clefts in both sides of apicodorsal lobe (Fig. 4 A). In dorsal view, apicodorsal lobe (adl) long, extending posterad, bifid apically, with pair of pointed shoulders laterally (Fig. 4 A) (three specimens in Iwate Prefecture bear pair of rounded shoulders laterally (Fig. 4 Aa )); in lateral view apicodorsal lobe like sharp claws (Fig. 4 C). Segment X (X) long, straight, extending posteroventrad in lateral view (Figs 4 C, 4 D); bilobed apically in dorsal view, each apex round (Fig. 4 E). Pair of anal sclerites (as) fused together, wide, round in ventral view, with pair of dark pigmented protuberances apically (Fig. 4 F), and with long common root basally. Apical band (ab) sclerotized, u-shaped in ventral view and fused with tergal band basally (Fig. 4 F); tergal band (tb) wide, flattened, well sclerotized apically, connecting to dorsum of phallotheca anteriorly (Fig. 4 D). Basal segment of each inferior appendage setose, elongate, basal half slightly thicker (Figs 4 B, 4 C). Apical segment of each inferior appendage rounded, right trapezoid in left lateral view (Fig. 4 C), apical half bearing spinules mesally. In phallic apparatus, phallotheca (pht) cup-shaped in lateral view (Fig. 4 D); aedeagus (aed) long, almost cylindrical, tapering to apex (Figs 4 D, 4 G); dorsal appendage of phallic apparatus (dap) sclerotized, shorter than aedeagus, basal 3 / 4 fused with aedeagus, apical margin slightly rounded, protruded mesally (Figs 4 D, 4 G). Pair of parameres (par) long cylindrical, each tapering to apex, dilated subapically, bearing many small spines ventrally around mid-length (Figs 4 B, 4 D). Female genitalia (Figs 5 A – 5 E). Segment VIII (VIII) with dorsal cleft (dc) wide and deep in dorsal view (Fig. 5 A), with pair of deep lateral clefts (lc) extending to middle part of segment (Fig. 5 B), and with posteroventral margin rounded, semicircular (Fig. 5 C). Intersegmental membrane of segment VIII – X (ismVIII – X) deeply invaginated into segment VIII, slightly sclerotized, dorsally into anterior margin, ventrally into middle part of segment VIII, anterior part fixed to interior wall of segment VIII (Figs 5 A – 5 C). In vaginal apparatus, posterior process (pp) sclerotized, long bottle shape in ventral view (Fig. 5 E), anterior half curved ventrad (Fig. 5 D); processus spermathecae (ps) small, long oval in lateral view, covered by basal part of posterior process (Fig. 5 D). Immature stage. Unknown.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA0FF8DFF77F92C5B83F9D3.taxon	materials_examined	Holotype. Male (in alcohol): Shibukuro-gawa, Tazawako-tamagawa, Senboku-shi, Akita Prefecture, Honshu, Japan, 39 ° 56 ’ 20 ” N 140 ° 42 ’ 22 ” E, alt. 485 m, 18 – 25. vi. 2018, K. Aoya (LBM 1410012663). Paratypes. Honshu: Iwate: 1 male (pinned), 1 female (pinned, fig. 1 D), Seiren-no-taki, Uchikawame, Hanamaki-shi, 10. viii. 1994, T. Hattori (SPMN); 1 male, 1 female, tributary Tobetsu-gawa, Yamagata-cho, Kuji-shi, 12. vi. 2004, N. Kuhara (LBM 1410012664 – 1410012665). Akita: 2 males (pinned, fig. 1 C), Toroko, Hachimantai, Kazuno-shi, 4. vii. 2019, M. Ookura (SPMN); 1 male, type locality, 28. ix – 5. x. 2018, K. Aoya (LBM 1410012666); 1 male, type locality, 5 – 13. x. 2018, K. Aoya (LBM 1410012667). Other specimens examined. Honshu: Aomori: 1 male, 1 female, Akaishi-gawa, Komori-machi, Ajigasawamachi, 6. vi. 1982, M. Kobayashi (KPM-NKMK 71010); 1 male, Sasanai-gawa, Iwasaki, Fukaura-machi, 7. vi. 1982, M. Kobayashi (KPM-NKMK 71080). Iwate: 4 males, 1 female, Matsukusa, Kuzakai, Miyako-shi, 12. vii. 1997, N. Kuhara (KuN- 14991) (NKa); 1 male, 3 females, same data, N. Kuhara (KuN- 14995) (NKa); 6 males, Oyama-gawa, Kadoma, Miyako-shi, 13. vii. 1997, N. Kuhara (KuN- 14982) (NKu). Akita: 1 male (pinned), Koirikawa, Hachimori, Happou-cho, 14. vi. 2019, M. Ookura (MTa); 1 male (pinned), Numanosawa, Tazawako, Senboku-shi, 24. ix. 2013, M. Tanaka (MTa); 1 male (pinned), Kotaki-zawa, Nakasen, Daisen-shi, 13. vii. 2010, M. Tanaka (MTa).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA0FF8DFF77F92C5B83F9D3.taxon	distribution	Distribution and biology. Rhyacophila humerigera sp. nov. is distributed in northern part of Tohoku District in Honshu (Fig. 16 D). Adults were collected near mountain streams in June to October by sweeping, Malaise traps or light traps.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA0FF8DFF77F92C5B83F9D3.taxon	etymology	Etymology. The Latin species epithet “ humerigera ” (Latin adjective, with a pair of shoulders) is derived from the shape of the apicodorsal lobe of the segment IX in male genitalia: a pair of shoulders on both sides of the apicodorsal lobe. Japanese name. Kadoo-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA3FF80FF77F9955B83FB83.taxon	description	(Figs 1 E, 1 F, 6 A – 6 H, 7 A – 7 E, 16 D)	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA3FF80FF77F9955B83FB83.taxon	diagnosis	Diagnosis. The male genitalia of R. koryne sp. nov. are slightly similar to those of R. motakanta and R. orthacantha in having the apically bifid, straight apicodorsal lobe of segment IX, but R. koryne sp. nov. is easily distinguished from the latter by the shape of the apicodorsal lobe which is long, club-shaped in lateral view (Fig. 6 C). On the other hand, the shapes of the apicodorsal lobes of the other two species are short, acute apically (not club-shaped) in lateral view (Figs 9 B, 11 B). Female genitalia of this species are very similar to those of R. orthacantha (Figs 7 A – 7 E, 15 A – 15 D), and both species cannot be distinguished from each other in the present study. However, the distributions of both species are clearly allopatric (Fig. 16 D). Adult (Figs 1 E, 1 F). Length of each forewing: male 8.6 – 12.3 mm (mean = 10.8, SD = 0.89, n = 21), female 11.8 – 13.0 mm (mean = 12.5, SD = 0.52, n = 5). Forewing coloration of R. koryne sp. nov. (Figs 1 E, 1 F) similar to that of R. humerigera sp. nov. Small mesal ventral process on posterior margin of sternites VI and VII in male and sternite VI in female abdomens.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA3FF80FF77F9955B83FB83.taxon	description	Male genitalia (Figs 6 A – 6 H). Segment IX in lateral view, very short ventrally, long dorsally and widely rounded posterolaterally (Fig. 6 C), subquadrate in dorsal view, with pair of clefts in both sides of apicodorsal lobe (Fig. 6 A); apicodorsal lobe long triangular with bifid apex in dorsal view (Fig. 6 A), long club shaped in lateral view (Fig. 6 C). Segment X long, extending posteroventrad in lateral view (Fig. 6 E); bilobed apically, each apex blunt in dorsal view (Fig. 6 F). Pair of anal sclerites fused together, wide, rounded in ventral view (Fig. 6 G), with pair of dark pigmented protuberances apically, and with long common root basally (Fig. 6 G). Apical band sclerotized, u-shaped in ventral view, fused with tergal band basally; tergal band wide, flattened, well sclerotized apically, connecting to dorsum of phallotheca anteriorly (Fig. 6 E). Basal segment of each inferior appendage setose, elongate, basal half slightly thicker (Figs 6 B – 6 D). Apical segment of each inferior appendage rounded, right trapezoid in left lateral view (Fig. 6 B), apical half bearing spinules mesally (Fig. 6 D). In phallic apparatus, phallotheca near cup-shaped in lateral view (Fig. 6 E); aedeagus long, almost cylindrical tapering to apex (Figs 6 B, 6 E, 6 H); dorsal appendage of phallic apparatus sclerotized, shorter than aedeagus, basal 3 / 4 fused with aedeagus, apex slightly protruded in middle (Figs 6 E, 6 H). Parameres long cylindrical, tapering to apex, dilated subapically, with a few small spines ventromesally around mid-length (Figs 6 B, 6 E). Female genitalia (Figs 7 A – 7 E). Segment VIII with dorsal cleft excavated to apical 1 / 4, tiny protrusion usually present mesally (Fig. 7 A), but occasionally absent, with pair of lateral clefts extending to apical 1 / 3 (Fig. 7 B), and posteroventral margin rounded, semicircular (Fig. 7 C). Intersegmental membrane of segment VIII – X (ismVIII – X) deeply invaginated into segment VIII, slightly sclerotized, dorsally into anterior margin, ventrally into middle part of it, anterior part fixed to interior wall of segment VIII (Figs 7 A – 7 C). In vaginal apparatus, posterior process sclerotized, long bottle shape in ventral view (Fig. 7 E); anterior half slightly curved anteroventrad in lateral view (Fig. 7 D); processus spermathecae small, long rectangular in lateral view, covered by basal part of posterior process (Fig. 7 D). Immature stage. Unknown.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA3FF80FF77F9955B83FB83.taxon	materials_examined	Holotype. Male (in alcohol): Shingo-yuno, Niimi-shi, Okayama Prefecture, Honshu, Japan, 35 ° 00 ’ 58 ” N, 133 ° 19 ’ 44 ” E, alt. 550 m, 1. vi. 2013, K. Nojima (LBM 1410012668). Paratypes. Honshu: Hyogo: 1 male, 1 female, Amagoike, Takenouchi, Wadayama-cho, Asago-shi, 25. v. 2004, K. Inazu (SPMN). Okayama: 2 males, 1 female, Uno, Kamo-cho, Tsuyama-shi, 6. v. 2013, K. Nojima (LBM 1410012669 – 1410012671); 3 males, 1 female, same data as the holotype (LBM 1410012672 – 1410012675); 6 males, 1 female, Koshiwata, Kagamino-cho, 9. vi. 2013, K. Nojima (LBM 1410012676 – 1410012682); 2 males, Ogaya, Nishi-awakura-son, 12. v. 2016, K. Nojima (LBM 1410012683 – 1410012684). Other specimens examined. Honshu: Hyogo: 1 male, Sugawara, Kishida, Shin-onsen-cho, 30. v. 2004, K. Inazu (NKa); 1 male (Fig. 1 E), 1 female (Fig. 1 F), Mihara, Takeno-cho, Toyooka-shi, 9. vi. 2009, K. Inazu (NKa); 1 female, Kumanami, Muraoka-ku, Kami-cho, 4. vi. 2006, K. Inazu (NKa); 1 male, Itabami, Nishigouchi, Chikusa-cho, Shisô-shi, 23. v. 2016, K. Inazu (NKa); 1 female, Mimuro-no-taki, Kouchi, Chikusa-cho, Shisô-shi, 14. vii. 2016, K. Inazu (NKa). Okayama: 6 males, 3 females, Akawase-keikoku, Kami-saibara, Kagamino-cho, 8. vi. 2011, K. Nojima (NKa). Tottori: 1 female, Kachi-gawa, Wakasa-cho, 12. ix. 2002, T. Hattori (SPMN); 1 male, Yukawagawa, Yukawa, Nichinan-cho, 11. ix. 2008, N. Kuhara (KuN- 15026) (NKu). Shimane: 1 male, Sada-cho, Izumo-shi, 15. ix. 1993, H. Nishimoto (SPMN).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA3FF80FF77F9955B83FB83.taxon	distribution	Distribution and biology. Rhyacophila koryne sp. nov. is distributed in western Honshu (Fig. 16 D). Adults were collected near mountainous streams in May to September by sweeping or light traps.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA3FF80FF77F9955B83FB83.taxon	etymology	Etymology. The species epithet “ koryne ” (Greek noun, club) is derived from the shape of the apicodorsal lobe of the segment IX of male genitalia in lateral view. Japanese name. Maruo-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFAEFF86FF77FB255B9DF808.taxon	description	(Figs 8 A – 8 C, 12 A – 12 D, 16 A)	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFAEFF86FF77FB255B9DF808.taxon	diagnosis	Diagnosis. Rhyacophila retracta Martynov 1914 is clearly distinguished from other species of the R. retracta Species Group by the following unique genital characters: In males, the short, trilobed apicodorsal lobe of segment IX (Figs 8 A, 8 B); in females, segment VIII with a deep dorsal cleft and a pair of shallow lateral clefts (Figs 12 A, 12 B). Specimens examined. Hokkaido: 1 female, Horokaishikari-gawa, Kamikawa-cho, 6. vii. 1993, M. Sato (SPMN): 1 female, Yamabe-nishi, Furano-shi, 16. vii. 1996, T. Kishimoto (SPMN); 1 female, Shikaribetsu, Shikaoicho, 27. viii. 1995, unknown collector (SPMN); 1 male, Shirogane-no-taki, Ofuyu, Hamamasu-ku, Ishikari-shi, alt. 5 m, 31. vii. 2006, T. Ito & T. Hattori (SPMN); 1 male, 4 females, Ponbetsu-gawa, Ikushunbetsu, Mikasa-shi, 22. vi. 1997, T. Ito & A. Ohkawa (SPMN); 1 male, 1 female, Takino, Sapporo-shi, 28. vii. 1978, T. Ito (SPMN); 1 male, Jozankei, Sapporo-shi, 23. viii. 1995, H. Nishimoto (SPMN); 2 males, 6 females, Ôtaki, Date-shi, 24. viii. 1995, H. Nishimoto (SPMN); 32 males, 16 females, Ken-ichi-gawa, Kumaishi-ayukawa-cho, Yakumo-cho, alt. 50 m, 23. vi. 1997, T. Ito & A. Ohkawa (SPMN); 3 males, same locality, 22. vii. 1997, same collectors (SPMN); 1 male, same locality, 25. viii. 1997, same collectors (SPMN); 1 male, Himekawa, Mori-machi, 29. ix. 1993, T. Ito (SPMN); 4 males, 9 females, same locality, 24. vi. 1997, T. Ito & A. Ohkawa (SPMN); 1 male, Shamisen-daki, Shikabe-cho, 11. ix. 2006, T. Ito (SPMN); 1 female, Uzurakawa, Assabu-cho, 30. v. 2003, T. Ito & A. Ohkawa (SPMN); 1 female, Kouzurakawa, Assabu-cho, 22. vi. 2003, T. Ito & A. Ohkawa (SPMN); 2 females, Ikusagawa, Nanae-cho, 23. vi. 2003, T. Ito & A. Ohkawa (SPMN); 1 male, 10 female, same locality, 11. ix. 2006, T. Ito (SPMN); 1 female, Idesu-kawa, Siriuchi-cho, 8. vii. 1978, T. Ito (SPMN); 1 male, 1 female, Mt. Horoshiri, Toyonuka, Biratori-cho, 25. vii. 2017, K. Inazu (NKa). Tsushima Islands: 1 male, Azu-kawa, Izuhara-machi, Tsushima-shi, 3. vi. 1984, M. Kobayashi (KPM-NKMK 77850).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFAEFF86FF77FB255B9DF808.taxon	distribution	Distribution. Rhyacophila retracta is broadly distributed in Hokkaido, Tsushima Islands, Korea, northeastern parts of China, Sakhalin, Kuril Islands, continental parts of Russian Far East and southern Siberia (Fig. 16 A: Yang et al. 2005; Ivanov 2011; Taira et al. 2025). Kobayashi (1985) recorded females as this species from Kanagawa, central Honshu, but I identified them (KPM-NKMK 76740) deposited in the Kobayashi collection of KPM as an unknown species belonging to the Rhyacophila angulata Species group Ross 1956. Japanese name. Ueno-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF87FF77FF7C5BD6FA73.taxon	description	(Figs 9 A – 9 C, 13 A – 13 D, 16 B)	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF87FF77FF7C5BD6FA73.taxon	diagnosis	Diagnosis. The male genitalia of R. motakanta are similar to those of R. orthacantha in having the apically bifid, short apicodorsal lobe, but R. motakanta is easily distinguished from R. orthacantha by bearing the apically truncated anal sclerite without any protuberances apically (Fig. 9 C) (whereas R. orthacantha has the anal sclerites with pair of dark pigmented protuberances apically (Fig. 11 C )). The female of R. motakanta is easily distinguished from those of other species by the shape of the vaginal apparatus: The apical part of the posterior process narrows abruptly in lateral and ventral views (arrows in figs 13 C, 13 D). Specimens examined. Honshu: Iwate: 3 females, Yakushi-gawa, Taimagura, Etsunagi, Miyako-shi, 10. viii. 1994, T. Hattori (SPMN). Akita: 2 males, 3 females, Asahi-kawa, Nibetsu, Akita-shi, 20. vi. 1997, T. Hattori (SPMN). Yamagata: 4 males, Sagae-shi, 18 – 22. vii. 1994, Murakami (SPMN); 3 males, Asahi Mineral Spring, Tateki, Asahi-machi, 2. viii. 1983, S. Uchida (KPM-NKMK 74290); 4 males, 6 females, Higashi-zawa, Hirokawara, Iide-machi, 3. vii. 1998, T. Hattori (SPMN). Tokyo: 2 males, 9 females, Nippara-gawa, Okutama-machi, 5. vi. 1991, T. Kagaya & T. Nozaki (TNo). Kanagawa: 1 male, Karasawa, Nakatsugawa, Kiyokawa-mura, 14. vi. 1989, S. Uchida (TNo); 1 male, 2 females, Shiraishizawa, Yamakita-machi, 12 – 13. v. 1983, T. Nozaki (TNo). Nagano: 2 males, 4 females, Narai-gawa, Shiojiri-shi, 12. vi. 2012, T. Ito (SPMN); 1 female, Kamanashi-gawa, Hakushu-cho, Hokuto-shi, 11. vi. 1994, T. Hattori (SPMN). Gifu: 3 males, Tokuyama-dam, Fujihasi, Ibigawa-cho, 17. vii. 1992, F. Hori (SPMN). Shizuoka: 5 females, Sugehiki-gawa, Nakaizu-cho, Izu-shi, 14. v. 1995, T. Hattori (SPMN). Shiga: 2 males, Takatoki-gawa., Kohara, Yogo-cho, Nagahama-shi, 22. v. 2010, H. Morita (NKa); 5 males, 47 females, same locaality, 27. v. 2008, T. Ushijima (NKa); 23 males, 1 female, same locality, 28. v. 2008, T. Ushijima (NKa). Hyogo: 1 male, 1 female, Akioka, Kami-cho, 4. vi. 2006, K. Inazu (NKa); 1 male, 1 female, Kouro, Chikusa-cho, Shisô-shi, 26. vi. 2016, K. Inazu (NKa). Nara: 1 male, Kawaai, Tenkawa-mura, alt. 600 m, 26. v. 1974, T. Hattori (SPMN). Shikoku: Kagawa: 1 female, Kaba-kawa, Shionoe-cho, Takamatsu-shi, 23. v. 2000, E. Yamamoto (SPMN). Ehime: 2 females, Namakusa-dani, Odamiyama, Oda-cho, 29. v. 1999, E. Yamamoto (SPMN). Kochi: 2 males (pinned), Kuroson, Okuyanai, Shimanto-shi, 22. v. 2011, T. Hattori (SPMN); 11 males, Befu-kyo, Monobe-cho, Kami-shi, 28. v. 2004, M. Takai (SPMN); 13 males, Shirai-dani, Teragawa, Ino-cho, 1. vii. 2005, M. Takai (SPMN); 1 male, 2 females, same locality, 20. vi. 2006, M. Takai (SPMN).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF87FF77FF7C5BD6FA73.taxon	distribution	Distribution and biology. Rhyacophila motakanta is widely distributed in Honshu, Shikoku and Kyushu (Fig. 16 B: Taira et al. 2025). Adults of this species were collected near streams in May to August. Taira (2023) reported that this species had a univoltine life cycle in central Honshu. Japanese name. Motakanta-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF85FF77FA345895FB83.taxon	description	(Figs 10 A – 10 C, 14 A – 14 D, 16 C)	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF85FF77FA345895FB83.taxon	diagnosis	Diagnosis. The male genitalia of R. lambakanta are very distinctive among the R. retracta Species Group in the shape of the apicodorsal lobe of segment IX: Narrow, long, and arcuately curving posteroventrally in apical half (Figs 10 A, 10 B). The female genitalia of R. lambakanta are similar to those of R. motakanta and R. humerigera sp. nov. in having a medium-sized dorsal cleft and a pair of lateral clefts in segment VIII (Figs 5 A – 5 C, 13 A – 13 B, 14 A – 14 B), but can be distinguished from them by the characters given in the diagnosis of R. humerigera sp. nov. Specimens examined. Honshu: Miyagi: 1 male, Natori-gawa, Futakuchi Onsen, Akiu-machi, Sendai-shi, 8. vi. 1974, T. Hattori (SPMN). Yamagata: 1 male, 1 female, Shizu, Nishikawa-machi, 18 – 19. ix. 2004, H. Nishimoto (SPMN). Tochigi: 1 male, Daiya-gawa, Nikko-shi, 6. x. 2002, H. Nishimoto (SPMN). Tokyo: 6 males, 1 female, Ôkumotori-dani, Nippara-gawa, Okutama-machi, alt. 1300 m, 5. vi. 1991, T. Nozaki (Nka). Kanagawa: 3 males, Shiraishizawa, Yamakita-machi, 12 – 13. v. 1982, T. Nozaki (Nka). Niigata: 8 males, 5 females, Wasabi-zawa, Ôtokoro, Itoigawa-shi, alt. 1150 m, 14. viii. 1998, T. Hattori (SPMN); 1 male, Yahei-gawa, Ôtokoro, Itoigawa-shi, alt. 1600 m, 31. viii. 2023, D. Kato (NKa). Ishikawa: 1 male, Chûgu, Hakusan-shi, 29. ix. 2001, H. Nishimoto (SPMN). Yamanashi: 1 pupa (male), Sakuba-daira-bashi, Ichinose-takahashi, Enzan, Kôshu-shi, alt. 1300 m, T. Hattori (SPMN); 3 males, 2 females, Hirogawara, Ashiyasu-ashikura, Minami-arupusu-shi, 13. viii. 1973, T. Hattori (SPMN); 1 male, Kamanashi-gawa, Hakushu-cho, Hokuto-shi, alt. 900 m, 1. vi. 1997, T. Hattori (SPMN). Nagano: 2 males, Kuro-sawa, Yokokawa, Tatsuno-machi, alt. 1050 m, 17. viii. 1996, T. Hattori (SPMN); 1 male, Oguro-gawa, Ina-shi, alt. 1400 m, 17. viii. 1996, T. Hattori (SPMN); 10 males, 1 female, Shio-kawa, Kashio, Ôshika-mura, alt. 1400 m, T. Hattori (SPMN). Gifu: 1 male, Namai, Taki-machi, Takayama-shi, 9. vi. 2003, H. Nishimoto (SPMN); 5 males, same locality, 24. vi. 2004, H. Nishimoto (SPMN); 4 males, 1 female, same locality, 18. vi. 2005, H. Nishimoto (SPMN); 1 male (pinned), 2 females (pinned), Iwai-machi, Takayama-shi, 9. vi. 2011, T. Hattori (SPMN); 1 female, Otome-keikoku, Kashimo, Nakatsugawa-shi, 8. vi. 2003, H. Nishimoto (SPMN); 1 male (pinned), 1 female (pinned), Hora, Miyagawa-cho, Hida-shi, 9. vi. 2011, T. Hattori (SPMN); 1 male, Tsurumi, Fujihashi, Ibigawa-cho, 29. v. 2002, N. Kawase (NKa). Shizuoka: 3 males, 5 females, Nishihikage-zawa, Umegashima, alt. 900 m, Shizuoka-shi, 5. vi. 1999, T. Hattori (SPMN); 10 males, 2 females, same locality, 28. v. 2014, T. Hattori & T. Nozaki (SPMN); 4 males, 6 females, Higashi-zawa-deai, Umegashima, Shizuoka-shi, alt. 900 m, 23. vii. 1994, T. Hattori (SPMN); 2 females, Abe-kawa, Nyû-jima, Shizuoka-shi, alt. 375 m, T. Hattori (SPMN). Shiga: 1 male, Takatoki-gawa, Yogo-cho, Nagahama-shi, 28. v. 2008, T. Ushijima (NKa); 1 male, Intani, Kitahira, Ôtsu-shi, 30. iv. 2014, S. Takeda (NKa); 1 male, Katsuragawa-sakashita-cho, Ôtsu-shi, 20. v. 2013, S. Takeda (NKa). Kyoto: 1 pupa (male), Kurama, Kyotoshi, 19. v. 1974, T. Hattori (SPMN).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF85FF77FA345895FB83.taxon	distribution	Distribution and biology. Rhyacophila lambakanta is distributed from northeastern to central Honshu, Japan (Fig. 16 C: Taira et al. 2025). Adults of this species were collected near streams in late April to early October. Hattori (2005) indicated that this species was found in rather higher altitude than R. motakanta and R. orthacantha. Japanese name. Yumi-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFA9FF85FF77FA345895FB83.taxon	discussion	Remarks. Kobayashi (1984) recorded a male collected from Sado Island (Sadogashima) as R. lambakanta. I examined his specimen (KPM-NKMK 72950) and found that the apicodorsal lobe of segment IX of his male is clearly shorter than that of R. lambakanta described above. Further research is needed to confirm the specific identity of this male.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFABFF85FF77FB255BE7F82C.taxon	description	(Figs 11 A – 11 C, 15 A – 15 D, 16 D)	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFABFF85FF77FB255BE7F82C.taxon	diagnosis	Diagnosis. The male genitalia of R. orthacantha are similar to those of R. motakanta in having a short, apically bifid apicodorsal lobe of segment IX, but can be distinguished from the latter by the characters given in the diagnosis of R. motakanta. The female genitalia of this species are indistinguishable from those of R. koryne sp. nov. as indicated in the diagnosis of R. koryne sp. nov. Specimens examined. Honshu: Tokyo: 1 male, Ôkumotori-dani, Nippara-gawa, Okutama-machi, alt. 1300 m, 5. vi. 1991, T. Nozaki (TNo). Shizuoka: 2 females, Nigori-gawa, Umegashima, Shizuoka-shi, 9. vi. 2002, T. Hattori (SPMN); 2 males, 1 female, Warashina-gawa, Yunoshima, Shizuoka-shi, alt. 300 m, 7. v. 1995, T. Hattori (SPMN); 6 males, 2 females, same locality, 11. v. 2001, T. Hattori (SPMN); 1 female, Ituka-zawa, Tashiro, Ikawa, Shizuoka-shi, alt. 750 m, T. Hattori (SPMN). Mie: 2 males, 2 females, Kawachi-dani, Yamaguchi, Fujiwara-cho, Inabe-shi, alt. 250 m, 4. vi. 2006, T. Hattori (SPMN). Shiga: 1 male, Takatoki-gawa, Yogo-cho, Nagahama-shi, 28. v. 2008, T. Ushijima (NKa). Nara: 7 males, Kawaai, Tenkawa-mura, 26. v. 1974, T. Hattori (SPMN); 1 male, Dorokawa, Tenkawa-mura, 15. v. 2004, H. Nishimoto (SPMN).	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
C97B87ACFFABFF85FF77FB255BE7F82C.taxon	distribution	Distribution and biology. R. orthacantha is distributed in central Honshu (Fig. 16 D: Taira et al. 2025). Adults were collected from mountain streams by sweeping or light traps in May to June. Taira (2023) reported that this species had a univoltine life cycle in central Honshu. Japanese name. Togari-mijikao-nagare-tobikera.	en	Kawase, Naoki (2025): Three new species of the Rhyacophila retracta species group (Trichoptera, Rhyacophilidae) from Japan. Zootaxa 5691 (3): 561-578, DOI: 10.11646/zootaxa.5691.3.6, URL: https://doi.org/10.11646/zootaxa.5691.3.6
