Stempellinella, Brundin, 1947

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 : 358-359

Key to adult males of the genus Stempellinella from the Russian Far East and Eastern Siberia

1. Both tibial combs on mid and hind tibia with 1 spur. Median setae weak and short, located close to the anal point ( Figs. 5 , 40 , 45 ). Median volsella with simple stem, without microtrichia ( Figs 7 , 40 , 46 )...................................... 2

- Only one tibial comb on mid and hind tibia with spur. Medial setae strong and long, located far from the anal point ( Figs 15 , 50 ). Median volsella with palmate stem or lobe-shaped, with microtrichia ( Figs 16 , 51 )............................. 4

2. AR <0.7. Frontal tubercles small or absent. Median volsella long, S-shaped ( Fig. 40 ).......................................................................................... Stempellinella coronata Inoue, Kawai et Imabayashi

- AR> 0.9. Frontal tubercles well developed, conical. Median volsella curved posterior ( Figs 7 , 46 ).................... 3

3. Superior volsella simple, oval form ( Fig. 46 ). Anal tergite with 3–5 small median tergite setae close to anal point ( Fig. 45 )..................................................................... Stempellinella edwardsi Spies et Saether

- Superior volsella consist of 2–3 lobes bearing medial setae ( Figs 6–7 ). Anal tergite with 6–8 small median setae between anal crests ( Fig. 5 )............................................................... Stempellinella bazovae sp. nov.

4. Median volsella 35–45 μm long, with palmate stem and 7–10 lamellae ( Fig. 51 )........ Stempellinella tamaseptima (Sasa)

- Median volsella oval or round shape, 21–30 μm long, with 10–15 small setae ( Fig. 16 )....... Stempellinella chirka sp. nov.

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).

FIGURES 35–40. Details of the structure of the male of Stempellinella coronata Inoue, Kawai et Imabayashi, 2004. 35—head and antenna; 36—wing; 37–38, 40—hypopygium; 39—superior and inferior volsellae, dorsal view. Scale bar 20 µm (35–38), 50 µm (39–40).

FIGURES 41–46. Details of the structure of the male of Stempellinella edwardsi Spies et Saether, 2004. 41—head; 42—wing; 43—median volsella; 44–45—hypopygium; 46—superior, median and inferior volsellae, dorsal view. Scale bar 20 µm (41–44), 50 µm (45–46).

FIGURES 8–16. Details of the structure of the male of Stempellinella chirka sp. nov. 8—head; 9—antenna; 10—wing; 11, 15—hypopygium, dorsal view; 12, 14—hypopygium, ventral view; 13—hypopygium, lateral view; 16—superior, median and inferior volsellae, dorsal view. Scale bar 20 µm (8–14), 50 µm (15–16).

FIGURES 47–51. Details of the structure of the male of Stempellinella tamaseptima (Sasa, 1980). 47—head; 48—wing; 49– 50—hypopygium; 51—superior and median volsellae, dorsal view. Scale bar 20 µm (47–49), 50 µm (50–51).