Rheocricotopus (Psilocricotopus) togakuroasi Sasa & Okazawa 1992

Rheocricotopus (P.) togakuroasi (Sasa & Okazawa, 1992) Figs 8–9, Table 7 Rheocricotopus (Paracricotopus) togakuroasi Sasa & Okazawa, 1992: 105. Rheocricotopus (Paracricotopus) akagisecundus Kikuchi & Sasa, 1994: 114. Syn. nov. Rheocricotopus gotocedeus Sasa & Suzuki, 2001a: 145. Syn. nov. Rheocricotopus (Psilocricotopus) akagisecundus – Saether et al. 2000: 160, as R. (P.) agakisecundus (misspelling). — Ashe & O’Connor 2012: 559. — Yamamoto & Yamamoto 2014: 296. Rheocricotopus (Psilocricotopus) togakuroasi – Saether et al. 2000: 161. Paracricotopus togakuroasi – Ashe & O’Connor 2012: 456. — Yamamoto & Yamamoto 2014: 285. — Namayandeh & Ghaderi 2025: 152. Rheocricotopus (Psilocricotopus) gotocedeus – Ashe & O’Connor 2012: 564. — Yamamoto & Yamamoto 2014: 296. Type material Holotype of Rheocricotopus (Paracricotopus) togakuroasi JAPAN – Toyama • ♂; Toga, Momose; 11 Aug. 1990; T. Okazawa and M. Sasa leg.; NSMT, NSMT-IDip 4757 [No. 189: 51]. The holotype specimens of R. (Paracricotopus) akagisecundu s and R. gotocedeus were not examined. Other material examined JAPAN – Shizuoka • 1 ♀ (pharate) with Le, 2 L; Shimizu, Yanbara, Yanbara River; 35°3′ N, 138°27′ E; 170 m a.s.l.; 17 May–13 Jun. 1988; H. Niitsuma leg.; PCHN • 1 Pe; Suruga-ku, Yoshida River; 35°59′ N, 138°26′ E; 49 m a.s.l.; 8 Feb. 1988; H. Niitsuma leg.; PCHN • 1 ♂; Aoi-ku, Ashikubo; 35°2′ N, 138°21 E; 84 m a.s.l.; 15 Feb. 1996 (emerged 26 Mar. 1996); H. Niitsuma leg.; PCHN • 1 ♂ with Pe, 1 ♂ (pharate); Aoi-ku, Dainichi Pass, unnamed stream; 35°11′ N, 138°15′ E; 1100 m a.s.l.; 4 May 1998 (emerged 10 May 1998); H. Niitsuma leg.; PCHN • 1 ♂ with Pe; same data as for preceding; 28 Mar 2001 (emerged 7 Apr. 2001); PCHN • 1 Pe with Le; same data as for preceding; 16 Sep 2022; PCHN. – Fukushima • 1 ♂ with Pe and Le, 1 P with Le; Iwaki, Yaguki; 37°8′ N, 140°54′ E; 123 m a.s.l.; 15 Aug. 2001 (emerged 30 Aug. 2001); H. Niitsuma leg.; PCHN • 1 ♂ with Pe; same data as for preceding; 18 Mar. 2007 (emerged 29 Mar. 2007); PCHN. CHINA – Sichuan • 1 ♂; Liangshan, Huili, Liuhua; 27°5′ N, 102°23′ E; 1540 m a.s.l.; 26 Apr. 2021; J.Y. Shi leg.; JNU. Description Male (n = 6) Total length 2.2–3.1, 2.5 mm. COLOURATION. Head dark brown on vertex. Body mostly yellowish brown with thorax darkened on 3 scutal vittae, Sct, Pn and Pe; occasionally thorax entirely dark brown except pale HP and its surroundings. Legs uniformly dark brown. HEAD. Temporals 3–5, 4. AR 0.81–1.0, 0.9. Clypeus trapezoid with 10–15, 13 setae. Lengths (μm) of Pm 1–5: 37–47, 40 (4): 52–62, 57 (4); 98–148, 120 (5); 111–160, 134 (5); 209–303, 246 (5), respectively. Pm 4 /Pm 3 1.1–1.3, 1.1 (5); Pm 5 /Pm 4 1.6–1.9, 1.8 (5). Pm 3 with 2–4, 3 SCl; occasionally 1 (2) SCl present on Pm 4. THORAX (Fig. 8A). Lateral Aps 1–6, 4 (5). Ac 10–15, 13, longest 20–28, 24 μm long; Dc 7–10, 9, including 1–3, 2 H; Pa 3, 3. Scts 4–8, 6. HP large, oval; usually dorsal part indistinct in outline. WING (Fig. 8B). Length 1.5–2.5, 1.9 mm. C extended moderately beyond end of R 4+5; extension 44–64, 55 μm long. VR 1.1–1.2, 1.1. R with 5–17, 9 setae. R 1 and R 4+5 usually bare; occasionally R 1 with 1 (2) seta, R 4+5 with 2 (1) setae. AnL developed, obtuse. Sq with 5–8, 6 setae. LEGS. P 1 with ti spur 46–57, 51 μm long; P 2 with 2 ti spurs, 18–25, 20 and 15–22, 18 μm long; P 3 with 2 ti spurs, 39–52, 46 and 15–22, 19 μm long. P 2 with 1–5, 3 Sch on ta 1. P 3 with ti comb consisting of 10–12, 11 bristles. Lengths and proportions of legs as in Table 7. ABDOMEN. T I–VIII (Fig. 8C) with setae irregularly arranged. Hypopygium (Fig. 8D) with Anp pointed apically, bearing 8–11, 9 (5) lateral setae. Gc 157–212, 182 μm long, 3.2–4.0, 3.5 × as long as broad at middle; SVo (Fig. 8E) thin, roundly protruded; IVo simple, triangular, with blunt apex. Gs (Fig. 8F) 79–101, 89 μm long, slender, tending to protrude outwards at subapex, with low, broad and apically rounded CD. HR 1.9–2.3, 2.0. Pharate female (n = 1) COLOURATION. Vertex dark brown. Thorax yellow with dark brown 3 vittae, Sct, Pn and Pe. Abdomen yellowish brown. SCa pale yellow. HEAD. Temporals 4 or 5. Antenna 5-segmented with terminal Fm 89 μm long. THORAX. Ac present. Dc 8, including 2 H; Pa 3. GENITALIA. S VIII with 8 setae in total. T IX (Fig. 8F) undivided, with 12 setae. Cercus 77 μm long. No 94 μm long. SCa 69 μm long, 1.2 × as long as broad. Pupa (n = 8) Total length 2.8–3.8, 3.1 mm. COLOURATION. Exuviae pale brown with dark abdominal Apo and middle and posterior spines on abdomen. CEPHALOTHORAX. FA (Fig. 9A) weakly rugose, with FS 44–49, 47 (5) μm long. Scutum weakly pebbled dorsally. Thoracic horn (Fig. 12L) 261–389, 309 (7) μm long, 3.7–5.1, 4.4 (5) × as long as broad. Lengths (μm) of Pc 1–3: 111–167, 133 (5); 185–221, 198 (5); 57–111, 74 (5), respectively. Lengths (μm) of Dc 1–4: 57–79, 69 (5); 30–69, 45 (5); 17–44, 29 (5); 39–76, 58 (5), respectively. These dorsocentral setae arranged in straight line. Distances (μm) of Dc 1 –Dc 2, Dc 2 –Dc 3, Dc 3 –Dc 4: 69–91, 80 (5); 39–91, 60 (5); 15–20, 18 (5), respectively; distance ratio of Dc 1 –Dc 2 to Dc 2 –Dc 3 0.92–1.75, 1.42 (5). ABDOMEN (Fig. 9B). T I–II without spinulation; T III–VI and VIII each with sporadic, faint, more or less extensive spinulation; T VII with faint median spinulation; T IX with anterior spinulation. T IV– VI usually with median strong spine patch, occasionally without these median spines; T IV with 0–7, 2 median spines, longest 2–7, 4 (5) μm long; T V with 0–10, 5 median spines, longest 5–15, 10 (7) μm long; T VI with 0–20, 10 median spines, longest 10–17, 13 (7) μm long. T II with rows of hooklets on posterior margin. T III–VIII each with rows of spines on posterior margin. Anteriorly directed spinules present, posterior to hooklet or spine rows on T II–V. S V–VI each with rows of spines, occasionally of 2 or 3 spines, on posterior margin. PSB present on segments II–III. Segment I with 2 L-setae; II–VI each with 3 L-setae; VII with 4 LS-setae; VIII with 4–5, 4 (4) LS-setae, or 1 simple L- and 4 LS-setae (3). L 1, 2 -setae on segments II–VI long, nearly ½ × as long as segment length, some of them apically split. AL 221–265, 245 (5) μm long, 1.9–2.1, 2.0 (5) × as long as broad, with 5–11, 8 lateral taeniae on posterior ⅓–½. Larva (n = 6) Total length 3.5 (1) mm. Length of head capsule 387–411 (2) μm. COLOURATION. Head yellow with darkened PM. HEAD. CI 0.7 (1). PM 207–239, 221 μm long. Dorsal surface (Fig. 9C) with frontoclypeolabrum and lateral labral sclerites. Labrum with bifid SI. At least one pair of ChB apically bifid. Lengths (μm) of 1 st –5 th antennal segments: 68–85, 78 (5); 23–28, 25 (5); 7–8, 8 (5); 6–7, 6 (5); 7 (5) respectively. AR 1.6–1.8, 1.7 (5). First segment (Fig. 9D) 3.4–4.5, 4.0 (5) × as long as broad, with RO located 0.10–0.18, 0.15 (5) from base and single SA located 0.10–0.14, 0.12 (4); apically with Bl 41 (1) μm long, reaching 4 th segment; Abl 23–26, 24 (3) μm long. Second segment apically with LO 8–10, 9 (5) μm long, and St 2–3, 3 (4) μm long. Pm 64–70, 67 (5) μm long. Mandible (Fig. 9E) 127–143, 136 (4) μm long; Si with 6 or 7 branches. Maxilla (Fig. 9F) with PG consisting of 9 distinct teeth; anterior LCh 2.7–4.5, 3.4 × as long as broad. M (Fig. 9G) with 2 simple median teeth; combined width of these median teeth 31–34, 33 μm. Amp 13–20, 17 μm wide at most, with 15–17, 16 beard setae beneath. BODY. With setae 98–148, 135 μm long. Pc (Fig. 9H) 33–34, 34 (4) μm long, 1.7–1.8, 1.7 (4) × as long as broad, with 1 spur and 3 anal setae. PP with 15 or 16 claws, small claws somewhat squashed. Distribution The species has been known only from Palaearctic Japan. Here, a record is added from Oriental China (Sichuan). Remarks Sasa & Okazawa (1992: 105–106) described this species based on a single male from Toyama Pref., Japan, and wrote: “The distribution of setae on abdominal tergites are arranged into two transverse rows and thus it has characters typical of the genus Paracricotopus Thienemann and Harnish, 1932 ”. However, a re-examination of the holotype disclosed that the tergal setae actually are irregularly arranged (see Fig. 8C). Additionally, humeral pits are large on the postpronotum as written in the original description (Sasa & Okazawa 1992: 106), “scutum with a pair of large humeral pits”. The species does not belong to the genus Paracricotopus, but to the genus Rheocricotopus. Specimens collected recently from Japan show the following features: male with a low, broad and apically rounded crista dorsalis; pupa usually with a median spine patch on each of the tergites IV– VI; and larval head capsule yellow with a largely dark brown postmentum. These features are unique in subgenus Psilocricotopus. The pupa especially is highly unusual among described pupae of R. (Psilocricotopus) in having rounded spine patches on the abdominal tergites IV–VI, a feature usual in pupae of Rheocricotopus (s. str.). Although we could not examine the holotypes of Paracricotopus akagisecundus Kikuchi & Sasa, 1994 and Rheocricotopus gotocedeus Sasa & Suzuki, 2001a, these species may be junior synonyms of R. (P.) togakuroasi. Judging from the original descriptions, we found no significant difference between R. (P.) togakuroasi and these two species. The holotypes of both species were not found, thus should be considered lost.