Stempellinella bazovae, Orel, 2023

Orel, Oksana V., 2023, Stempellinella Brundin, 1947 (Diptera: Chironomidae) from Eastern Siberia and the Russian Far East, with the description of new species, Zootaxa 5380 (4), pp. 341-360 : 342-344

Stempellinella bazovae sp. nov.

Figs 1–7 .

http://zoobank.org/NomenclaturalActs/ 9BF2F371-DDFC-4469-91B5-25CEB35CF92E

Stempellinella sp. 2 Makarchenko et Orel, 2023: 145.

Type material. HOLOTYPE: male, RUSSIA: PRIMORYE TERRITORY, Dalnerechensky district , Bolshaya Ussurka River near the village of Salskoye, 16.vii.2003, leg. O. Zorina. PARATYPES: 1 male, same data as holotype; REPUBLIC OF BURYATIA, Irkutsk city, Salenga river basin, Uda River near the Institute of General and Experimental Biology SB RAS, 28.vi.2011 , 1 male, leg. N. Bazova.

Derivatio nominis. The new species is named in honor of Natalia Bazova, a researcher at the Institute of General and Experimental Biology of the Siberian Branch of the Russian Academy of Sciences, who provided a great help in collecting the material.

Diagnosis. Male: yellowish brown coloured species, with wing 0.90–1.16 mm long and AR 0.97–1.08; ultimate flagellomere 304–344 μm; length of 2–4 flagellomeres of maxillary palpomeres 231–261 μm. LR PI 1.64–1.79. Combs of mid and hind tibiae with 2 spurs. T-shaped anal tergite band; lateral seta absent; anal point with numerous small spinulae and 6–8 setae between anal crests; small median tergite setae at anal point base absent; superior volsella medially divided into three lobes; median volsella strongly curved, without microtrichia, with simple lamellae, stem of median volsella 15 μm long.

Description. Adult male (n=3). General colour yellowish brown. Total length 1.2–1.3 mm; total length/wing length 1.18–1.33.

Head ( Fig. 1 ). Frontal tubercles conical, 12–21 μm long. Temporal setae 4–5. Clypeus with 9–10 setae. Maxillary palp yellowish, 231–261 μm long; lengths of last 4 palpal segments (μm): 18–24, 51–60, 69–81, 93–108. Palp length/head width 1.37. Scapus brown, flagellomeres (1–10) dark-brown, 616–664 μm long. AR 0.97–1.08. Ultimate flagellomere 304–344 μm long. Antenna length/palp length 2.44–2.54.

Thorax. Ground colour of scutum yellowish brown, mesonotal strips brown or dark brown. Ac 12, Dc 5–9, Pa 1. Scutellum yellowish or yellowish brown, with 4–6 setae. Postnotum dark brown.

Wing length 0.90–1.16 mm ( Fig. 2 ). R, R 1 with 24–30 setae, R 4+5 with 18–23 setae, Cu 1 with 6–8 setae, M 3+4 with 8–14 setae, Cu with 14 setae, An with 15–24 setae. VR 1.31–1.66.

Legs ( Table 1 ). Legs yellowish. Fore tibia with 15 mm long spur; terminal combs of Ti 2 and Ti 3 with 2 spurs, 12 μm long. BR 1 3.0–4.3, BR 2 5.0–5.6, BR 3 6.4–6.8. Sensilla chaetica on Ta 1 P 2 absent.

Abdomen. Yellowish brown.

Hypopygium ( Figs 3–7 ). Anal tergite bands T-type; lateral setae absent; small microtrichia-free areas present on each side of anal point base. Anal point 36–45 μm long, wide at about apical 1/3, apically thin and pointed; with numerous small spinulae and 6–8 small median setae between anal crests; 7–8 lateral setae at anal point base. Gonocoxite 60–75 μm long; with 2–3 setae along inner margin. Width of transverse sternapodeme 36–48 μm. Phallapodeme 45–57 μm long. Superior volsella 30–36 μm long, with 3–4 dorsal and 3 median setae located on 2–3 lobes ( Fig. 6 ), without microtrichia. Digitus absent. Median volsella 45 μm long strongly curved posteriorly with simple lamellae; stem of median volsella 15 μm long, without microtrichia. Inferior volsella 45–60 mm long, apically club-shaped, with 5–6 distal setae. Gonostylus 42–48 μm long, with 3–4 setae in apical part and 1 apical seta. HR 1.43–1.64.

Female, pupa and larva unknown.

Remarks. The males of a new species are most similar to Stempellinella edwardsi Spies et Saether, 2004 , but differ from the latter by the following features: wing length 0.90–1.16 mm, AR 0.97–1.08, R, R 1 with 24–30 setae, small median setae located between anal crests, superior volsella medially divided into three lobes, stem of median volsella 15 μm long (see Table 2 ).

Distribution. Russian Far East (Primorye Territory) and Transbaikal region (Buryatia).

Figures

FIGURES 1–7. Details of the structure of the male of Stempellinella bazovae sp. nov. 1—head and antenna; 2—wing; 3–5— hypopygium; 6—superior volsella, dorsal view; 7—superior, median and inferior volsellae, dorsal view. Scale bar 20 µm (1–4), 50 µm (5–7).

Tables

TABLE 1. Length (μm) and proportions of legs of the male Stempellinella bazovae sp. nov. (n=3)

P	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta 5
P1	384–456	232–280	416–480	216–256	176–200	120–136	72
P 2	440–504	344–408	432–224	80–120	72–80	40–56	40–56
P3	464–560	360–440	264–328	152–160	128–136	80–88	48–72
P	LR	SV	BV
P1	1.64–1.79	1.48–1.56	1.75–1.84
P2	0.52–0.56	4.07–4.16	3.64–4.21
P3	0.72–0.75	3.05–3.17	2.57–2.91