Corynoneura hortonensis Fu & Saether 2012, sp. n.

• Main Authors: Fu, Yue, Saether, Ole A.
• Format: Text
• Language: unknown
• Published: Zenodo 2012
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Insecta; Diptera; Chironomidae; Corynoneura; Corynoneura hortonensis; Northwest Territories; Canada; Seta; Humps; Horton River
• Online Access: https://dx.doi.org/10.5281/zenodo.5258043; https://zenodo.org/record/5258043

Corynoneura hortonensis sp. n. (Figs 16 A–G) Type material. Holotype male, CANADA: Northwest Territories, Horton River (6921'N, 12649.8'W), 4.vii.2000, Bohdan Bilyj (CNC). Paratypes: 4 males, 1 female, as holotype (ZMBN). Etymology. Named after the type locality. Diagnostic characters. The male is similar to C. kedrovaya Makarchenko et Makarchenko in the shape of the inferior volsella and gonostylus, but the two species can easily be separated as the tergite IX of C. kedrovaya has 4– 6 long setae, the phallapodeme is strongly curved and the joint with the sternapodeme is placed pre–laterally, while in C. hortonensis tergite IX of the male is without long setae, the phallapodeme is slightly curved and placed in a caudal position of the sternapodeme. The male is also similar to C. sundukovi Makarchenko et Makarchenko in the shape of the inferior volsella and sternapodeme, but the two species can easily be separated as the superior volsellae of C. sundukovi are large with almost right-angled corner, while in C. hortonensis the superior volsellae are small. Genitalia of female very simple, without any long setae, coxosternapodeme with only 1 lateral lamella. Male (n = 3–5) Total length 0.96–0.98, 0.97 mm. Wing length 0.66–0.74, 0.70 mm. Total length/wing length 1.3–1.5, 1.4. Wing length /profemur length 2.8. Coloration . Head brown; thorax and legs brown; abdominal tergites I–VI yellow, VII–IX brown. Head . Eyes bare. Antennae in all specimens broken. Tentorium 110–120, 114 µm long, 11–15, 13 µm wide; stipes 41 µm long, 3 µm wide. Clypeus with 5–7, 6 setae. Lengths of palpomeres (in µm): 6–8, 7; 10–12, 11; 12– 19, 17; 21–24, 22; 51–55, 53. Palpomere 5/3 ratio 2.1–2.9, 2.4. Thorax . Antepronotals absent. Dorsocentrals 6–7, prealars 2. Scutellum with 2 setae. Wing (Fig. 16 A). VR 3.6–3.9, 3.7. Cu/wing length 0.56–0.60, 0.58; C length 326–358, 341 µm long; Cu 420– 432, 426 µm long; wing width/wing length: 0.44–0.46, 0.45; costa with 6–8, 7 setae. Legs. Fore trochanter with dorsal keel. Spur of fore tibia 16–20, 18 µm long; of mid tibia 10–13, 11 µm long; of hind tibia 11 µm and 25–28, 26 µm long. Width at apex of fore tibia 18–22, 20 µm; of mid tibia 15–17, 16 µm; of hind tibia (a) 32–36, 33 µm. Width of hind tibia 1 / 3 from apex (d) 15–18, 17 µm; elongation length (b) 33–37, 35 µm; length of maximum thickening (c 1) 55–63, 59 µm; total length of thickening (c 2) 97–104, 99 µm; a/d 1.9–2.1, 2.0; b/d 1.8–2.3, 2.1; c 1 /d 3.6–4.2, 3.8; c 2 /d 5.7–6.4, 6.1. Hind tibia expanded, with comb of 12–18, 14 setae, one seta near spur strongly S-shaped (Fig. 16 G). Lengths of leg segments and their proportions as in Table 14. Hypopygium (Fig. 16 B–C). Tergite IX medially concave with posterior humps. Laterosternites IX without a long seta. Superior volsella small and anteriomedially fused. Inferior volsella slightly rounded and fused with the inner margin of gonocoxite, with 1–3 strong setae. Phallapodeme curved, 30–35, 32 µm long. Transverse sternapodeme 18–22, 20 µm. Megaseta 4–6 µm long. HR 1.9–2.3, 2.1; HV 3.1–3.3, 3.2. Female (n = 1) Total length 0.89 mm. Wing length 0.71 mm. Total length/wing length 1.30. Coloration . Head brown; thorax and legs yellowish brown; abdomen as in male but paler. Head. Eyes bare. Antenna broken. Tentorium 69 µm long, 7 µm wide. Palpomere lengths (in µm): 15, 14, 18, 25, 37. Palpomere 5/3 ratio 2.1. Palpomere 2 small, palpomeres 3, 4 and 5 elliptical. Clypeus with 6 setae. Thorax. Antepronotals 0, dorsocentrals 7, prealars 2. Scutellum with 2 setae. Wing (Fig. 16 D). VR 2.75. Wing broader than in male. C 340 µm long; Cu 440 µm long. C/wing length 0.49, Cu/wing length 0.60. Costa with 13 setae. Legs. Fore trochanter with distinct dorsal keel. Fore leg broken except femur; spur of mid tibia 10 µm long, of hind tibia 30 µm long. Width at apex of mid tibia 21 µm, of hind tibia (a) 30 µm. Width of hind tibia 1 / 3 from apex (d) 18 µm, elongation length (b) 33 µm, length of maximum thickening (c 1) 62 µm, total length of thickening (c 2) 102 µm; a/d 1.7, b/d 1.8, c 1 /d 3.4, c 2 /d 5.7. Hind tibia expanded, with comb of 12 setae, one seta near spur strongly S-shaped. Lengths of leg segments and their proportions as in Table 15. Abdomen. Setae not observable. Genitalia (Fig. 16 E–F). Without any long setae. Cercus 30 µm long, 21µm wide. Notum length 110 µm long. Coxosternapodeme with only 1 lateral lamella. Seminal capsules 44 µm long, 30 µm wide; neck length 10 µm long, width at apex 6 µm. Remark. The type material is not in a good condition, with the antennae and most of the legs broken. However, most of observable characters of the male separate the species from all other members of the genus. : Published as part of Fu, Yue & Saether, Ole A., 2012, 3536, pp. 1-61 in Zootaxa 3536 on pages 33-35