Manoa xianjuensis Qi & Lin, sp. n.

Manoa xianjuensis Qi & Lin sp. n.

( Figs 1–7)

Type material. Holotype (deposited in BDN): male (BOLD sample ID: XJ17), China, Zhejiang Province, Taizhou, Xianju, Kuocangshan Nature Reserve, Yukengcun, near stream, 28.63267°N, 120.57606°E, 190 m a.s.l., 24.V.2016, sweep net, X. Qi. Paratypes: 11 males, (BDN no. XJ18–25, XJ33, XJ36, XJ37), 3 females (ZSM no. XJ34, XJ35; BDN no. XJ16), sampling data as for holotype.

Etymology. Named after the type locality. The species epithet is adjectival for the purposes of nomenclature.

Diagnostic characters. The new species conforms to the genus descriptions in Andersen & Saether (1977) and Jacobsen & Perry (2002). The male of Manoa xianjuensis sp. n. can be separated from its congeners by the following combination of characters: frontal tubercles absent; AR 1.13–1.33; wing length 1.43–1.50 mm; wing vein R with 6–8 setae, R1 with 1–3 setae, squama with 1–3 setae; antepronotum with two lateral setae; LR1 0.96– 0.98; pars ventralis and digitus present. The female of Manoa xianjuensis sp. n. separated from its congeners by the following combination of characters: frontal tubercles absent; wing length 1.58–1.75 mm; R with 10–12 setae, R1 with 4 setae, R4+5 with 11–12 setae; costal extension with 2–3 non-marginal setae; squama with 2 setae; LR1 0.90– 0.93.

Description. Adult male (n = 4, unless otherwise stated). Total length 2.67–3.08, 2.91 mm. Wing length 1.43– 1.50, 1.49 mm. Total length/wing length 1.80–2.00, 1.92. Wing length/length of profemur 1.84–2.08, 1.97. Coloration (Figs 1, 2–4). Body pale apricot yellow.

Head (Fig. 5 a, b). Antenna with 13 flagellomeres; AR 1.13–1.33, 1.25. Temporal setae 12–16, 14, including 4 inner verticals, 7–12, 9 outer verticals, and 0–2, 1 postorbitals. Clypeus with 5–12, 9 setae. Tentorium 133–138, 135 mm long; 13–20, 17 mm wide. Palpomere lengths (in mm): 28–35, 32; 25–49, 38; 70–78, 75; 83–95, 90; 108– 138, 123. Palpomere ratio (5th/3rd) 1.54–1.77, 1.62. Third palpomere with 2–3, 3 lanceolate sensilla clavata.

Wing (Fig. 5 c). VR 1.09–1.32, 1.21. Anal lobe reduced. Membrane microtrichia distinctly visible at 100x magnification. Brachiolum with 2–3, 2 setae; R with 6–8, 7 setae; R1 with 1–3, 2 setae; costal extension 40–60, 50 mm long; with 0–1, 0 non-marginal setae; remaining veins bare. Squama with 1–3, 2 setae.

Thorax (Fig. 6 a). Antepronotum with 2 lateral setae. Acrostichals 9–10, 9; dorsocentrals 7–14, 11 in single row; prealars 2–3, 3; supraalar 1. Scutellum with 6 setae.

Legs (Fig. 5 d–f). Spur of fore tibia 38–48, 42 mm long; spurs of mid tibia 33–50, 42 and 32–48, 39 mm long; of hind tibia 50–58, 54 and 45–54, 49 mm long. Apical width of fore tibia 38–48, 40 mm; of mid tibia 38–43, 40 mm; of hind tibia 41–50, 46 mm. Lengths (in mm) and proportions of legs as in Table 1.

fe ti ta1 ta2 ta3 ta4

p1 710–850, 770 680–800, 723 650–780, 695 300–360, 325 240–280, 258 160–200, 180 p2 740–850, 795 680–800, 725 330–450, 378 160–200, 175 120–150, 133 90–100, 95 p3 810–900, 853 750–810, 775 480–540, 503 230–270, 248 190–200, 195 110–140, 125 ta5 LR BV SV BR

Hypopygium (Fig. 6 b-d). Laterosternite IX with 2–4, 3 setae. Tergite IX with 36–44, 39 setae; anal point absent. Transverse sternapodeme 25–40, 35 mm long, 13–25, 18 mm wide; phallapodeme 85–113, 101 mm long. Gonocoxite 145–163, 152 mm long; with triangular pars ventralis. Superior volsella 63–75, 70 mm long; 7–13, 10 mm wide; dorsal surface with basal microtrichia and 2–3, 2 setae; ventral surface with numerous long microtrichia and 2 apical setae. Digitus 15–30, 19 mm long; with pointed apex. Inferior volsella pediform, 50–58, 53 mm long; with 9–14, 13 long setae. Median volsella vestigial; with 2–3, 2 apical setae. Gonostylus straight; 95–108, 104 mm long; with pointed apex. HR 1.34–1.58, 1.47; HV 2.46–2.86, 2.67.

Adult female (n = 2, unless otherwise stated). Total length 2.92–3.05 mm. Wing length 1.58–1.75 mm. Total length/wing length 1.67–1.94. Wing length/length of fore femur 2.06–2.31.

Coloration. As in male (Figs 3, 4).

Head (Fig. 7 a, b). Antenna (Fig. 7 a) with 6 flagellomeres; AR 0.30–0.32; flagellomere lengths (in mm): 75–88, 65–68, 68–70, 65 (2), 55 (2), 100–110. Temporal setae 15–16, including 3–4 inner verticals, 6–11 outer verticals and 2–5 postorbitals. Clypeus with 10–13 setae. Tentorium 95–135 mm long, 18–19 mm wide. Palpomere lengths (in mm): 33–40, 45–50, 70–78, 88–90, 150 (1). Palpomere ratio (5th/3rd) 1.92 (1). Third palpomere with 2–3 lanceolate sensilla clavata.

Wing. VR 1.20–1.23. Anal lobe reduced. Membrane microtrichia distinctly visible at 100x magnification. Brachiolum with 2 setae; R with 10–12 setae; R1 with 4 setae; R4+5 with 11–12 setae; costal extension 45–65 mm long, with 2–3 non-marginal setae. Squama with 2 setae.

Thorax (Fig. 7 c). Antepronotum with 2 lateral setae. Acrostichals 7–9; dorsocentrals 6–11 in single row, prealars 3, supraalar 1. Scutellum with 6 setae.

Legs. Spur of fore tibia 38–40 mm long, spurs of mid tibia 38–43 and 33–40 mm long, of hind tibia 39–50 and 36–45 mm long. Apical width of fore tibia 38–40 mm, of mid tibia 40–43 mm, of hind tibia 38–48 mm. Lengths (in mm) and proportions of legs as in Table 2.

Abdomen. Numbers of setae on tergites I–VIII: 14–20, 18–28, 18–34, 22–38, 28–30, 24–30, 18–38, 6–20. Numbers of setae on sternites I–VIII: 6–8, 4–7, 12–16, 21–30, 22–31, 24–38, 32–40.

Genitalia (Fig. 7 d, e). Sternite VIII divided, with 50–55 mm long notched floor (Fig. 7 e) under vagina; floor with approximately 32–44 setae. Tergite IX with 22 setae; gonocoxite IX with 1–2 setae. Cercus 78–100 mm long, with 42–48 setae. Seminal capsules 65–68 mm long, including 13–18 mm long, collar-shaped neck, 38–40 mm wide. Spermathecal ducts curved. Notum 75–88 mm long. Dorsomesal lobe 71–73 mm long.

fe ti ta1 ta2 ta3 ta4

p1 680–850 690–750 640–690 290–310 220–250 140–170 p2 780–850 710–770 350–400 150–160 110–130 80–90 p3 880–950 780–830 480–520 230–250 200 (2) 100–130

ta5 LR BV SV BR

p1 90–120 0.92–0.93 2.71–2.76 2.14–2.32 2.00–3.00 p2 60–80 0.49–0.52 4.28–4.70 4.05–4.26 1.77–2.22 p3 80–90 0.62–0.63 3.43–3.51 3.42–3.46 1.80–2.00 Immature stages. Unknown.

DNA barcoding analysis. The neighbor joining tree (Fig. 8) based on available DNA barcodes unequivocally associates the adult males and females of M. xianjuensis sp. n., and supports differentiation of the new species from the other barcoded Pseudochironomini. In addition, we found two distinct clades of under the name Riethia stictoptera Kieffer, 1917 with the maximum intraspecific genetic distance 18.1%, which suggests at least one misidentification in the BOLD data.

Biology and ecology. The new species was collected using a sweep-net close to a small mountain stream in Kuocangshan Nature Reserve in subtropical China. We collected M. xianjuensis sp. n. during the rainy season in late May, when the temperature is 15–20°C.