Olecryptotendipes obtunsus, Mukherjee & Hazra, 2022

Mukherjee, Bindarika & Hazra, Niladri, 2022, First records of three genera, Cyphomella Saether, 1977, Olecryptotendipes Zorina, 2007 and Robackia Saether, 1977 of the Harnischia complex from India with description of O. extentus sp. n., O. obtunsus sp. n. and R. aequilongia sp. n. (Diptera: Chironomidae), Zootaxa 5091 (2), pp. 330-340 : 335-337

Olecryptotendipes obtunsus sp. n.

GenBank Accession no. MZ695837

LSIDurn:lsid:zoobank.org:act: 2E18995E-B925-4706-B2CE-899C36BFEB32

Material examined. Holotype male, labelled ‘ Holotype Olecryptotendipes obtunsus sp. n., India, West Bengal, Burdwan [23°22ʹN, 87°85ʹE], 10.ii.2021, Coll. N. Hazra’ . Paratype 2 males, same data as holotype, labelled ‘ Paratype Olecryptotendipes obtunsus sp. n., India, West Bengal, Burdwan [23°22ʹN, 87°85ʹE], 14.v.2020, Coll. N. Hazra’ . Paratype 1 male, same data as holotype, labelled ‘ Paratype Olecryptotendipes obtunsus sp. n., India, West Bengal, Burdwan [23°22ʹN, 87°85ʹE], 16.iv.2021, Coll. N. Hazra’ . Paratype 1 male, same data as holotype, labelled ‘ Paratype Olecryptotendipes obtunsus sp. n., India, West Bengal, Burdwan [23°22ʹN, 87°85ʹE], 15.vii.2021, Coll. N. Hazra’ .

Diagnosis. The new species is distinguished by the presence of an inverted Y-shaped superior volsella consisting of a non-sclerotised blunt outer part and a small sclerotised inner part, a parallel-sided anal point, weak shoulder-like corner on tergite IX and weak inferior volsella.

Etymology. The name ‘ obtunsus ’ a Latin word, refers to the blunt outer part of the superior volsella; to be treated as an adjective.

Male (n=5). Total length 2.9–3.03, 2.96 mm. Wing length 1.97–2.1, 2.03 mm. Costal length 1.90–2.00, 1.95 mm. Antennal length 0.82–0.85, 0.83 mm.

Colouration. Thorax dark brown. Leg and abdomen yellowish brown.

Head. Head width 530–550, 540 µm. Temporal setae 9–10 (IV 2–3, OV 5, Po 2). Clypeal setae 10–12. Frontal tubercles absent. Eyes bare with dorsomedial extension of 80–90, 155 µm.AR 1.82–1.93, 1.87; ultimate flagellomere 530–560, 545 µm long. Palpomere lengths (I–V) (µm): 20: 40–50; 45: 90–110; 100: 120: 130–140; 135. CA 0.65– 0.67, 0.66.

Thorax. Vittae present. Scutal tubercle absent. Acrostichals 10, dorsocentrals 6–7, prealars 3, supraalars 2–3, scutellars 6–8.

Wing ( Fig. 3A ). VR 1.07–1.12, 1.09. R 1 with 7–8 setae, R 4+5 bare. Brachiolum with 2 setae. Squama with 4 fringed setae. Anal lobe moderately developed.

Legs. Fore tibia with 3 setae. Mid legs with 2 tibial spurs; 23–25.3, 24.15 µm and 25.3–27.6, 26.45 µm long with 24–30 teeth. Hind leg with 2 tibial spurs; 27.6–29.9, 28.75 µm and 32.2 µm long with 44–50 teeth. Lengths and proportions of leg segments shown in table 3.

Abdomen. Tergite IX with weak shoulder-like corner on each side of anal point.

Hypopygium ( Figs. 3B–E ). Anal tergite band Y-shaped. Anal point parallel-sided, distally rounded, originating from caudal margin of anal tergite; 43.7–46, 44.85 µm long, 6.9–9.2, 8.05 µm wide. Anal point bearing 4 basally located lateral setae on each side. Transverse sternapodeme 39.1–43.7, 41.4 µm long, longitudinal sternapodeme 57.5–62.1, 59.8 µm long. Superior volsella variable shaped ( Figs. 3D–E ), 69–75.9, 72.45 µm long and 23 µm wide, slightly curved, apically somewhat inverted Y shaped, consisting of sclerotised shorter inner protrusion with 1 apical seta and 1 sub apical seta and a blunt non-sclerotised longer outer protrusion; covered with microtrichia in inner parts. Inferior volsella small, reaching beyond margin of anal tergite and covered with microtrichia. Gonocoxite 117.3–126.5, 122 µm long. Gonostylus 142.6–149.5, 146 µm long bearing 5 setae along inner margin. HR 0.82– 0.84, 0.83; HV 2.39–2.47, 2.43.

Distribution. West Bengal, India (present record).

Remarks. The new species is similar to Olecryptotendipes exilis Yan, Wang et Bu, 2012 in having a parallel sided anal point, two setae on the superior volsella and a microtrichiose inner part of the superior volsella, but the absence of a spur-like posterolateral projection of superior volsella and lobe on tergite IX can differentiate the new species from O. exilis . The shape of the gonostylus and presence of a weak shoulder-like corner on tergite IX are similar in both new species and O. melasmus Yan, Wang et Bu, 2012 but they differ in the shape of the superior volsella and anal point.

A world key to the species of the genus Olecryptotendipes Zorina, 2007 (♂) (revised after Yan et al. 2017)

1. Acrostichals absent; R bare (Palaearctic: Russia)....................................... O. secundus ( Zorina, 2003)

- Acrostichals present; R with setae........................................................................ 2

2(1). Thorax without dark brown spots..........................................................................3

- Thorax with dark brown spots........................................................................... 4

3(2). Inferior volsella absent; antepronotals 2 (Palaearctic: Russia, China)............................ O. lenzi ( Zorina, 2001)

- Inferior volsella lobe–like; antepronotals 6–7 (Oriental China).......................... O. exilis Yan, Wang et Bu, 2012

4(2). Superior volsella without projection...................................................................... 5

- Superior volsella with projection......................................................................... 6

5(4). Superior volsella simple, digitiform (Oriental China).................................. O. arienus Yan et Wang, 2017

- Superior volsella inverted, T-shaped in appearance (Orient: India) ( Fig. 4A ).......................... O. extentus sp. n.

6(4). Superior volsella curved basally, straight distally, with large posterolateral projection (Palaearctic and Oriental China)............................................................................. O. melasmus Yan, Wang et Bu, 2012

- Superior volsella with a partially sclerotised beak-like small projection and a flap-like blunt non-sclerotised apicolateral projection (Orient: India) (Fig 6A).......................................................... O. obtunsus sp. n.

Figures

FIGURES 3A–E. Adult male Olecryptotendipes obtunsus sp. n. A. Wing, B. Hypopygium, C. Hypopygium, scale 0.01 mm, D. Superior volsella, scale 0.01 mm, E. Superior volsella, scale 0.01 mm.

FIGURES 4A–D. Adult male Cyphomella camelus. A. Wing, B. Hypopygium (dorsal), C. Hypopygium, scale 0.01 mm, D. Hypopygium (ventral).