Two new species of Riethia Kieffer, 1917 from Chile and Ecuador (Chironomidae: Chironominae, Pseudochironomini) Andersen, Trond Malla, Annui Giłka, Wojciech Zootaxa 2024 2024-05-14 5448 4 499 507 Andersen & Malla & Giłka, 2024 Andersen & Malla & Giłka 2024 [151,413,330,357] Insecta Chironomidae Riethia Animalia Diptera 4 503 Arthropoda species ecuadoriensis sp. nov.  https://zoobank.org/ urn:lsid:zoobank.org:act: 58F17D34-5F7A-47E1-8954-6BBF2FBDA93B ( Figs 3A–C, 4A–C)   Type material.  Holotypeadult male (slide mounted under five coverslips), ECUADOR, Carchi Province, Reservaecológica  El Ángel,  LagUnas El Voladero, 0.691132°N 77.882543°W,  3.800 ma.s.l.,  21.x.1990, leg. K. Böttger( ZSM).  Paratypes, 21 adultmales as holotype ( ZSM, ZMBN).   Etymology.The epithet,  ecuadoriensis,is used as an adjective and meaning “from Ecuador” in reference to the country of origin of the holotype.  Diagnostic characters.  Riethia ecuadoriensisis a dark brown species, with uniformly coloured abdomen, without bands, except for subrectangular pale brown area on tergite VII, and with scattered microtrichia dorsally on the superior volsella. For other key characters see the diagnosis for  R. chilensisgiven above.   Description.Adult male (n = 5)  Body size and proportions.Total length 5.42–5.87, 5.65 mm. Wing length 3.30–3.53, 3.39 mm. Total length / wing length 1.59–1.75, 1.67. Wing length / length of profemur 2.72–2.90, 2.79.  Colouration.Head light brown with dark brown pedicel; thorax and legs brown ( Fig. 3B); abdomen brown, tergite VII with subrectangular pale brown area in posterior 1/3 flanked by brown lateral areas ( Fig. 3C). Wing hyaline ( Fig. 3A).  Antenna.AR 1.49–1.59, 1.54. Terminal flagellomere 817–850, 835 µm long.  Head. Temporal setae 16–19, 18, bi- to tri-serial. Clypeus with 15–20, 17 setae. Tentorium 195–230, 210 µm long, 59–68, 64 µm wide. Stipes 174–209, 197 µm long, 12–16, 15 µm wide. Palpomere lengths (in µm): 52–68, 61; 88–100, 92; 152–168, 158; 216–236, 226; 260–300, 285. Third palpomere with 5–7, 6 sensilla clavata subapically, longest about 28 µm long.  Thorax. Antepronotum with 1–4, 2 ventrolateral setae. Acrostichals weak, apparently 1–2, 2; dorsocentrals 8–12, 10 insingle row; prealars 3; supraalar 1. Scutellum with 7–11, 9 setae in single row.  Wing( Fig. 3A). VR 0.99–1.04, 1.02. Brachiolum with 2–3, 3 setae; R with 19–25, 23; R 1with 11–15, 13; R 4+5with 21–26, 24 setae; other veins and membrane bare. Squama with 14–17, 16 setae.  Legs. Spur of fore tibia 69–79, 74 µm long; spurs of mid tibia 64–79, 73 µm and 76–86, 81 µm long; spurs of hind tibia 75–86, 80 µm and 83–94, 89 µm long. Width at apex of fore tibia 58–68, 64 µm; of mid tibia 66–72, 70 µm; of hind tibia 70–79, 75 µm. Lengths and proportions of legs as in Table 2.   TABLE 2.Lengths (in µm) and proportions of legs of  Riethia ecuadoriensis  sp. nov., male.     p 1  p 2  p 3   fe 1174–1277, 1236 1339–1483, 1397 1421–1524, 1475   ti 1380–1442, 1401 1277–1380, 1335 1504–1607, 1566   ta 1 1401–1442, 1426 721–803, 766 1009–1071, 1051   ta 2 659–783, 737 412–474, 428 597–639, 622   ta 3 536–597, 573 288–350, 309 453–494, 478   ta 4 371–453, 420 227–247, 235 288–309, 305   ta 5 185–206, 198 144–165, 148 165–185, 169   LR 1.000–1.045, 1.018 0.565–0.582, 0.574 0.654–0.689, 0.671   BV 2.062–2.218, 2.110 2.900–3.231, 3.127 2.579–2.618, 2.599   SV 1.829–1.884, 1.850 3.462–3.658, 3.566 2.843–2.923, 2.894   BR 2.15–3.00, 2.60 2.50–3.26, 2.85 3.70–4.34, 3.99   FIGURE 3.  Riethia ecuadoriensis  sp. nov., male. A—wing; B—foreleg; C—abdomen.  Hypopygium( Figs 4A–C). Tergite IX with slightly convex posterior margin, with 48–63, 54 setae mainly in two to three rows along posterior margin. Laterosternite IX with 7–11, 9 setae. Phallapodeme 131–149, 140 µm long; with 35–51, 41 µm long, narrow, curved oral projection. Transverse sternapodeme straight, 51–68, 59 µm long, with weak oral projections. Gonocoxite 252–277, 259 µm long. Superior volsella stout, weakly curved, with narrowly triangular apex projecting medially to anteromedially, 76–83, 80 µm long, 32–37, 34 µm wide medially, with 6–7, 6 weak dorsal setae and scattered microtrichia. Inferior volsella strongly bent dorsally with bluntly subtriangular apical part, 58–66, 62 µm long, 41–46, 43 µm wide, with microtrichia, marginal setae, and 20–25, 22 broad flattened, apically fringed setae ( Fig. 4A  1) dorsally. Pseudovolsella consisting of bluntly triangular tubercle, with single, 52–58, 56 µm long, curved seta, with second curved setae at base. Gonostylus 200–212, 209 µm long. HR 1.19–1.35, 1.24. HV 2.41–2.81, 2.67. Female and immature stages unknown.   Geographical distribution and bionomics.The species is known only from páramo grassland in the high Andes in northern Ecuador, where the males were resting on Espeltiasp. close to a lake. 4866220301 1990-10-21 ZSM K. Bottger Ecuador Reserva 3800 0.691132 LagUnas El Voladero 1 -77.882545 El Angel 4 503 1 Carchi holotype 4866220304 [241,845,541,568] ZSM, ZMBN Ecuador 4 503 21 21 Carchi paratype