Rheocricotopus (Psilocricotopus) orientalis Wang 1995

Rheocricotopus (P.) orientalis Wang, 1995 Figs 12B–J, Table 10 Rheocricotopus (Rheocricotopus) orientalis Wang, 1995: 37. Rheocricotopus (Psilocricotopus) orientalis – Saether et al. 2000: 161. — Lin et al. 2020: 290. Rheocricotopus (Rheocricotopus) orientalis – Ashe & O’Connor 2012: 571. The type specimen of R. (s. str.) orientalis was not examined. Material examined CHINA – Guangdong • 1 ♂; Jiangmen, Taishan, Mt Beifeng; 22°10′ N, 112°55′ E; 230 m a.s.l.; 7 Jul. 2012; H.Q. Tang leg.; JNU • 1 ♂; Guangzhou, Huangpu, Jinyuan; 23°13′ N, 113°26′ E; 120 m a.s.l.; 29 Sep. 2016; H.Q. Tang leg.; JNU, JNU 161009005 • 1 ♂; Guangzhou, Zengcheng, Zhengguo, Lan stream; 23°20′ N, 113°58′ E; 230 m a.s.l.; 4 Jan. 2020; Y.R. He leg.; JNU, JNU LX09 • 1 ♂ (pharate); Zhaoqinag, Fengkai, Heishiding NNR; 23°27′ N, 111°51′ E; 310 m a.s.l.; 20 Mar. 2021; Z.X. Li leg.; JNU, JNU 24021901 • 5 ♂♂; same data as for preceding; 5 Nov.–15 Dec. 2021; Z.X. Li leg.; JNU, JNU 24041001 to 24041002, HSD39 • 5 ♀♀; same data as for preceding; 5–20 Apr. 2022; H.Q. Tang leg.; JNU, JNU 24040902, 24040904 • 3 Pe; same data as for preceding; 22 Apr. 2022; JNU, JNU 24041002 • 2 ♀♀; same data as for preceding; 3 Nov. 2022; JNU, JNU 24040903 • 1 ♀; Maoming, Xinyi, Mt Yunkai NNR; 22°16′ N, 111°11′ E; 1130 m a.s.l.; 12 May 2020; S.X. Luo leg.; JNU. Description Male (n = 8) Total length 2.1–2.5, 2.3 mm. COLOURATION. Head dark brown on vertex. Thorax mostly dark brown, with yellow pleural membrane; scutal vittae indistinct. Abdomen (Fig. 12B) bicoloured; T I and IV entirely yellow, remaining tergites dark brown. Legs brown. HEAD. Temporals 2–4, 3. AR 0.35–0.41, 0.38. Clypeus with 7–9, 8 setae. Lengths (μm) of Pm 1–5: 27–32, 29; 47–54, 51; 98–113, 106; 108–128, 114; 219–266, 235, respectively. Pm 4 /Pm 3 1.0–1.1, 1.1; Pm 5 /Pm 4 1.9–2.2, 2.1. Pm 3 with numerous SCl on 2 subapical oval depressions. THORAX. Lateral Aps 2–4, 3 (7). Ac 14–19, 17, longest 12–15, 13 μm long; Dc 6–8, 7, including 1–3, 2 H; Pa 3; Scts 4–5, 4. HP (Fig. 12C) large, oval, occasionally indistinct; usually sclerotized posterior margin partly visible. WING (Fig. 12D). Length 1.4–1.9, 1.6 mm. AnL much reduced; wing cuneiform, widest at around end of Cu 1. C extension 93–123, 106 (7) μm long. VR 1.1–1.2, 1.1. R with 7–14, 10 (7) setae; R 1 with 3–6, 4 (7) setae; R 4+5 with 5–8, 7 (7) setae. Sq with 1–2, 1 seta. LEGS. P 1 with ti spur 25–30, 28 μm long; P 2 with 2 ti spurs 15–20, 16 and 12–17, 14 μm long; P 3 with 2 ti spurs 37–42, 40 and 15–20, 17 (7) μm long. P 3 with ti comb of 12–13, 12 (7) bristles. Sch absent. Lengths and proportions of legs as in Table 10. ABDOMEN. Hypopygium (Fig. 12E) with T IX bearing setiferous, rounded, posterolateral lobes; AnP stout, with 12–18, 14 (7) lateral setae. Gc 143–157, 150 µm long, 3.4–4.4, 3.9 × as long as broad at middle, with SVo thin, triangular, rounded at apex; IVo 59–64, 61 µm long, digitate with apical and ventral fine setae, and longitudinal row of ventral long setae. Gs 81–86, 84 µm long, medially with triangular, well-developed CD. HR 1.7–1.9, 1.8. Female (n = 8) Total length 2.1–2.7, 2.3 mm. COLOURATION. Similar to male. SCa pale. HEAD. Temporals 3–5, 4. Lengths (μm) of Fm 1–5: 66–74, 70 (5); 57–66, 61 (5); 66–69, 67 (5); 59–71, 66 (5); 74–89, 80 (5), respectively. AR 0.28–0.33, 0.30 (5). Clypeus with 7–13, 9 setae. Lengths (μm) of Pm 1–5: 25–34, 30 (6); 47–54, 50 (6); 98–123, 109 (6); 106–140, 118 (6); 226–315, 267 (6), respectively. Pm 4 /Pm 3 1.0–1.1, 1.1 (6); Pm 5 /Pm 4 2.1–2.5, 2.3. Pm 3 with numerous SCl on 2 subapical oval depressions. THORAX. Lateral Aps 2–5, 3 (6). Ac 15–21, 18 (7); Dc 6–8, 7 including 2–3, 2 H; Pa 3; Sct 3–4, 4. WING. Length 1.6–1.8, 1.7 mm. C extension 118–148, 130 (7) μm long. VR 1.1, 1.1 (6). R with 11–17, 14 (7); R 1 with 6–9, 8 (7); R 4+5 with 14–22, 18 (6) setae. Sq with 1–2, 1 (7) seta. LEGS. P 1 with one ti spur 22–30, 24 (7) μm long; P 2 with 2 ti spurs, both 15–17, 16 μm long; P 3 with 2 ti spurs 37–49, 42 and 15–20, 17 μm long respectively, and with ti comb of 12–14, 13 (7) bristles. Lengths and proportions of legs as in Table 10. GENITALIA (Fig. 12F). S VIII with 6–9, 8 setae. Gp VIII divided into rounded VlL and narrow DmL; ApL distinct between VlL and DmL. T IX (Fig. 12G) undivided with 7–12, 9 setae including 2–6, 4 short setae. Gc IX well developed with 8–11, 9 setae on each side. Ce 44–71, 60 (6) μm long. No 111–130, 121 μm long. SCa 81–96, 91 (7) μm long, 1.2–1.3, 1.2 (3) × as long as broad, with conical neck; duct looped. Pupa (n = 4) Total length 3.2 (2) mm. COLOURATION. Exuviae pale brown with dark Apo and posterior spine rows on abdomen. CEPHALOTHORAX. FA (Fig. 12H) with short, blunt and somewhat pebbled warts. FS absent. Thoracic horn (Fig. 12I) 274–294, 282 (3) μm long, and 4.3–4.7, 4.4 (3) × as long as broad. Lengths (μm) of Pc 1–3: 98–113, 107 (3); 81–98 (2); 44–62, 52 (3), respectively; these arranged in triangle. Lengths (μm) of Dc 1–4: 57–62 (2); 62 (1); 30–44 (2); 34–49 (2), respectively. Distances (μm) of Dc 1 –Dc 2, Dc 2 –Dc 3, Dc 3 – Dc 4: 62–69 (2); 47–54 (2); 12 (2), respectively; these setae arranged in line; Distance ratio of Dc 1 –Dc 2 to Dc 2 –Dc 3 1.1–1.5 (2). ABDOMEN (Fig. 12J). T I without spinulation; T II–VI more or less extensive spinulation; T VII with triangular, posteromedial spinule patch; T VIII with anterior and posteromedial spinule patches; T IX with anterior spinule patch. Spine rows present on posterior margins of T II–VIII; these rows well developed, longest spine 25–30, 27 μm on T VIII. Conjunctives III/IV–V/VI and posterior margins of T III–V without anteriorly directed spinules. S IV–VII each with rows of spines on posterior margin. PSB absent. Segment I with 2 L-setae, II–VIII each with 3 L-setae, some L-setae apically split. L 1, 2 -setae relatively long on A II–VIII, these almost ½ × as long as segment length; L 3 -seta slightly shorter than L 1, 2 -setae. AL 221–239, 228 μm long, 2.0–2.2, 2.1 (3) × as long as broad, without lateral taeniae; male genital sac slightly longer than AL. Larva Unknown. Distribution Rheocricotopus orientalis is known only from Guangdong Province in Oriental China. Remarks Rheocricotopus orientalis was originally placed in subgenus Rheocricotopus, but subsequently, together with related species, transferred to subgenus Psilocricotopus by Saether et al. (2000: 161). We examined adult females, pupal exuviae and pharate male recently collected from Guangdong Province in China, and found that the female tergite IX is not divided into two protrusions, and the pupa possesses no frontal seta, no median spine or spinule patch on the tergites III–VI, and distinct caudal spines on the tergites VII and VIII. In addition, the pupa is very similar to that of R. (P.) albulus sp. nov. described here in those abdominal segments II–VIII bear three L-setae only and the anal lobe is without lateral taeniae. Therefore, this species belongs to subgenus Psilocricotopus. Within Rheocricotopus, the species is unique in the male tergite IX posterolaterally with setiferous rounded lobes, and in the pupal frontal apotome with short, blunt and pebbled warts. Wang & Saether (2001: 237) re-examined the holotype and wrote: “a lighter area mistakenly was taken as a humeral pit and there is no humeral pit in R. orientalis.” We examined sixteen adult specimens, consisting of eight males and eight females, newly collected from Guangdong Province, and found that in ten (63%) of them the sclerotized margin of a paler humeral pit is partly visible and in the remainder the structure is indistinct. Actually, all adults of the orientalis group, including R. (P.) bannaensis sp. nov. described here as a new member of this group, possess oval and large humeral pits.