Pagastia (P.) caelestomontana Makarchenko, Semenchenko et Palatov, 1959

Makarchenko, Eugenyi A., Semenchenko, Alexander A. & Palatov, Dmitry M., 2021, New species and findings of Pagastia Oliver (Diptera: Chironomidae: Diamesinae) from Central Asia, with DNA barcoding of known species of the genus, Zootaxa 4951 (3), pp. 559-570 : 562-564

Pagastia (P.) caelestomontana Makarchenko, Semenchenko et Palatov , sp. nov.

( Figs. 1–4 , 8–9 )

urn:lsid:zoobank.org:act:A9FDC949-20D5-45F4-A7DF-E5A889BF9ECD

Syndiamesa sp. 1, Kustareva & Ivanova 1980: 39, Fig. 9 .

Pagastia (P.) sp. 1 Makarchenko & Makarchenko 2000: 175, Figs. 1–9 .

Material. Holotype: adult male, Central Asia , Kirgizstan , Chuy Region , Alamudun district , Kyrgyz ridge of Tien Shan mountains , left tributary of the Ala-Archa River, 2.5 km above the cordon – the checkpoint of the Ala-Archa National Park, 27.V.2016, alt. 1717 m above sea level, N 42°37.743’, E 74°29.293’, leg. D. Palatov. Paratypes: 10 larvae, same data as holotype, same data as holotype except Ala-Archa River at the confluence of the Karabulak River , 28. V.2016, alt. 2061 m above sea level, N 42°36.200’, E 74°28.819’, leg. D. Palatov ; 1 adult male, 4 larvae, Kirgizstan, Talas Region, Talas district , Talas valley , Otmek River (left source), under the Otmek pass, 12. VI.2016. alt. 2801 m above sea level, N 42°19.084’, E 73°05.770’, leg. D. Palatov ; 18 larvae, Kirgizstan, Zailiyskiy Alatau, Turgen River , 20.VIII.1984, leg. N. Petrova. 3 larvae, Tajikistan, Gorno-Badakhshan Autonomous Region, Rushanskiy District, spring in front of the mouth of the Bartang River , 03.VII.2016, alt. 2025 m above sea level, N 37°55.493’, E 71°36.183’, leg. D. Palatov.

Derivatio nominis. From name of Tien-Shan mountains where was collected type material of a new species. Tien-Shan mountains in Chinese means "celestial mountains" and in Latin celestial is mean caelestis, mountains – montanus.

Adult male (n = 1).

Total length 4.5 mm. Total length/wing length 1.01.

Coloration. Head, thorax (except scutellum), legs, and abdomen brown to dark brown; antennae light brown; scutellum gray; wings greyish.

Head. Eyes bare and strongly extended dorsomedially. Temporal setae 29–34, including 4 coronals, 20 preoculars, 5–6 verticals, and 13 postorbitals. Clypeus with 42 setae. Antenna with 13 flagellomeres and well developed plume, these setae 840–1040 μm long; pedicel with 4 setae 38–40 μm long; terminal flagellomere with 1 subapical setae 56 μm long. AR 2.21. Palpomeres lengths (in μm): 112; 132; 200; 284; 340. Palpomere 3 in distal part with sensilla capitata (diameter 20 μm). Palpomeres 1–5 length/head width 1.21.

Thorax. Antepronotum with 4–5 dorsomedial and 12–18 ventrolateral setae. Acrostichals 15 (in middle part of mesonotum), dorsocentrals 26 (in 1–2 rows, in middle part), prealars 20–24 (in 2 groups), scutellars ca 60.

Wing. Length 4.44 mm; width 1.14 mm. Membrane without setae. R and R 1 with 39–40 setae; R 4+5 with 15–16 setae. Costa extension 56 μm long. RM length/MCu length 2.83–3.2. Anal lobe well developed and protrude for- ward, rounded. Squama with 39–40 setae 100–180 μm long, in 1–2 rows. VR 0.85.

Legs. Spur of fore tibia 112 μm long; spurs of mid tibia 80 μm; of hind tibia 124 μm and 84 μm long. Hind tibial comb with 16 setae. Lengths and proportions of leg segments as in Table 1 .

Hypopygium ( Figs. 2–4 , 8–9 ). Tergite IX with 18–24 setae on each side and with an anal point 80 μm long, apically with peg 28 μm long. Tergite IX laterally from anal point on each side with rounded small lobe ( Fig. 4 ). Laterosternite IX with 14–16 setae. Transverse sternapodeme trapezoidal, 312 μm long. Phallapodeme 52–56 μm long. Gonocoxite 292 μm long, basal lobe large, angular, with long setae along outer margin and with 2 setae at in- ner part ( Figs. 3 , 8 ). Median aedeagal lobe 80–88 μm long, wedge-shaped and with toothed apex; lateral aedeagal lobe narrow, 156–164 μm long ( Fig. 2 ). Gonostylus 252–256 μm long, massive, with a rounded or rounded-angular protrusion basally along the outer edge, with megaseta 20 μm long. HR 1.14–1.16.

Pupa unknown.

Larva was described as Pagastia (P.) sp. 1 by Makarchenko & Makarchenko (2000).

Diagnosis. The male of this new species is most closely related to P. (P.) hanseni sp. nov. and can be separated in the following features: antepronotum with dorsomedial and ventrolateral setae; clypeus with 42 setae; AR 2.21; Dc 26 (in 1–2 rows), Pa 20–24; basal lobe of gonocoxite large and angular, median aedeagal lobe wedge-shaped and with toothed apex, lateral aedeagal lobe 156–164 μm long, gonostylus massive and with rounded or rounded- angular protrusion basally along the outer edge. The male of P. (P.) hanseni sp. nov. has antepronotum completely covered with setae; clypeus with ca 90 setae; AR 3.80; Dc 53–54 (in 2–4 rows), Pa 47–50; basal lobe of gonocoxite middle-sized and rounded, median aedeagal lobe wedge-shaped and with fingerlike apex, lateral aedeagal lobe 132–140 μm long; gonostylus slender, almost straight, of same thickness, sometimes slightly widened at the base, slightly curved apically. The larva of P. (P.) caelestomontana sp. nov. differs from all known species by the presence on the head capsule dorsal and dorsolateral dark markings ( Makarchenko & Makarchenko 2000, Fig. 8–9 ). See also key above and results of DNA barcoding.

Ecology. Larvae were collected from stones and bowlders covered with algae and moss in mountain rivers, located at an altitude of 1717–2801 m, at a flow rate of 0.3–0.8 m /s, with water temperature ca 12°C and in spring at an altitude of 2025 m.

Distribution. Known only from the type locality in Tien Shan and Pamir Mountains (Kirgizstan and Tajikistan) ( Figs. 12, 15 ).

Figures

FIGURES 1–7. Pagastia (P.) caelestomontana sp. nov. (1–4) and P. (P.) hanseni sp. nov. (5–7), males. 1, 6, anteropronotum in dorsal view; 2, 7, aedeagal lobes; 3, 5, hypopygium in dorsal view; 4, anal point. Bl, basal lobe of gonocoxite; LAl, lateral aedeagal lobe; MAl, median aedeagal lobe TSa, transverse sternapodeme. Scale bars for figures 1, 3, 5, 6 – 200 µm, for figures 2, 4, 7 – 50 µm.

FIGURES 8–11. Pagastia (P.) caelestomontana sp. nov. (8–9) and P. (P.) hanseni sp. nov. (10–11), males. 8, 10, hypopygium in dorsal view; 9, gonostylus; 11, anal point.

FIGURES 12–15. Type localities of Pagastia (P.) caelestomontana sp. nov. (12), P. (P.) hanseni sp. nov. (13), and P. (P.) aff. lanceolata (Tokunaga) (14–15). 12, Otmek River, Talas district, Kirgizstan (photo by E.S. Chertoprud); 13, Soktosh River, Gorno-Badakhshan Autonomous Region, Roshtqal’a District, Tajikistan (photo by D.M. Palatov); 14, Tuzumtaikul River, Gorno- Badakhshan Autonomous Region, Shughnon District, Tajikistan (photo by M.V. Vinarski); 15, spring in front of the mouth of the Bartang River, Gorno-Badakhshan Autonomous Region, Rushanskiy District, Tajikistan (photo by M.V. Vinarski).