Lipurometriocnemus bogotensis, Ospina-Torres & Mey & Jaime-Murcia, 2018

Ospina-Torres, Rodulfo, Mey, Wolfram & Jaime-Murcia, Patricia, 2018, Two new orthoclad species from Colombian Andes (Diptera: Chironomidae), Zootaxa 4472 (2), pp. 385-392 : 386-388

Lipurometriocnemus bogotensis n. sp.

( Figs 1–6 )

Material examined: Holotype: male: COLOMBIA, Bogota D.C., Quebrada la Vieja , 2666 m.asl., 4°38'59.12'' N 74° 2'53.75” W, 6.2.2017, light trap, “Morfo 12” leg. R.Ospina-W.Mey ( ICN-MHN) . Paratypes: 3 males, same data as holotype ( ICN-MHN, ZSM) .

Derivatio nominis. The species is named after Bogotá, capital city of Colombia where the new species was found.

Diagnostic characters. The species differs from other members of the genus by the absence of acrostichals setae on thorax. After the key of Andersen et al. (2016) it keys to couplet 3, with setae on wing veins R1 and R4+5. L. bogotensis sp. n. share with L. glabalus the poorly developed inferior volsella but the hairs on wing veins R1 and R4+5 are as numerous as in L. biancae .

Description. Male (n=4).

Dimensions. Total length 3.05–3.18, 3.09 mm. Wing length 1.88–1.89, 1.88 mm. Total length/wing length 1.62–1.68, 1.64. Wing length/length of profemur 2.25–2.35, 2.3

Coloration. Thorax predominantly dark brown to black, abdominal tergites and legs black. Abdominal sternites I–V could appear swollen and partly light grey and transparent.

Antenna. AR 1.17–1.2, 1.18. Last flagellomere 520–530, 525 µm. long, pointed at apex.

Head ( Figure 1 ) Total temporal setae 10–11, 10. Inner verticals 3–4, 3. Outer verticals 3–4, 3. Postorbitals 3–4, 3. Clypeus longer than wide, with 18–21, 19 setae. Tentorium, stipes and cibarial pump as in Figure 3 . Tentorium 140–157, 146 µm long, 30–35, 33 µm wide. Stipes 147–162, 155 µm long, 25–35, 29 µm wide. Palp segments lengths (in µm): 30; 50–60, 57; 140–170,157; 150–170, 162; 160–180, 170.

Thorax. ( Figure 2 ) Anteropronotum with 4–5, 4 lateral setae. Acrostichals absent. Dorsocentrals: 33–39, 36 setae, uniserial to triserial. Prealars: 14–20, 17 setae, partly biserial. Supraalars absent. Preepisternals 4–5, 5 setae. Scutellum with 16–18, 16 setae arranged in two rows.

Wings. ( Figure 4 ) Wing membrane bare. Anal lobe scarcely developed. VR 1.28–1.31, 1.29. Costal extension 90–110, 103 µm long. Brachiolum with 2 setae. R with 29–31, 30 setae. R1 with 24–29, 27 setae, R4+5 with 42–52, 48 setae, Costal extension with 20–26, 22, of these 8–11, 9 non-marginal setae. R4+5 ending distal to end of M3+4. Squama with 11–13, 12 setae, partly biserial.

Legs. Spur of fore tibia 48–50, 49 µm. long. Spurs of mid tibia 32.5–35, 34.3 and 30–32.5, 31 µm. long. Spurs of hind tibia 52.5–62.5, 59 and 22.5–25, 24 µm. long. Width at apex of fore tibia: 32.5–40, 36. µm. Width of apex of mid tibia 35–37.5, 35.6 µm. Width at apex of hind tibia 40–45, 43.1 µm. Comb with 20–22, 21 setae, longest 45–50, 48.5, shortest 25–27.5, 26.8 µm. long. Pseudospurs present on mid and hind tarsomeres. Lenghts and proportions of legs Table 1.

Hypopygium. ( Figures 5–6 ) Tergite IX with 18 setae, Laterosternite IX with 4–5, 4 setae. Transverse externapodeme curved, 67.5–70, 68.7 µm long. Phalapodeme 75–82.5, 77.5 µm long. Virga small, nail shaped. Gonocoxite 177.5–185, 182.5 µm long, with 45–52.5, 50 µm long, 12.5–15, 13.1 wide inferior volsella ending 117.5–125, 123 µm from apex of gonocoxite. Gonostylus 90–95, 93.7 µm long, 17.5–20, 18.7 µm wide medially. Megaseta 7.5 µm. HR: 1.86 – 1.94, 1.90. HV: 3.21–3.41, 3.29.

Distribution and ecology. The species described here lives all the year under cold climatic conditions in a mountain basin and is the first record of the genus Lipurometriocnemus from the high Andean tropical region. The light traps were placed not far from the river, which is suggestive for an aquatic or semiterrestrial habitat of the immatures.

Remarks. Lipurometriocnemus Saether include species similar to Bryophaenocladius and Metriocnemus (eye bare and squama with setae) but without anal point and wing membrane bare ( Saether 1981) ( Cranston et al. 1989). When we first tried to identify the specimens of Lipurometriocnemus bogotensis sp. n., the lack of acrostichal setae made the species somewhat enigmatic but the coincidence with the rest of the morphological characters, according with the emended description of Andersen et al. (2016) and the key of Cranston et al. (1989) where the acrosticals are not used until the couplet 66 ( Lipurometriocnemus + Eukiefferiella ) convinced us to assign the new species to Lipurometriocnemus instead of describing a new genus.

Female and immatures. Unknown.

Figures

FIGURES 1–4. Lipurometriocnemus bogotensis sp. n. 1. Head (right posterior, left anterior view) and labial palps; 2. Thorax; 3. Tentorium, stipes and cibarial pump; 4. wing

FIGURES 5–6. Lipurometriocnemus bogotensis sp. n. 5. Hypopygium, dorsal view 6. Hypopygium without Tergit IX. Dosal aspect left; ventral aspect right.