Propsilocerus taimyrus Zelentzov

Makarchenko, Eugenyi A. & Semenchenko, Alexander A., 2023, Review of subfamily Prodiamesinae (Diptera: Chironomidae) from the Russian Far East and bordering territory, Zootaxa 5323 (1), pp. 1-26 : 19-21

Propsilocerus taimyrus Zelentzov

( Figs. 49–58 )

Propsilocerus taimyrus Zelentzov, 2000: 1242 ; Ashe & O’Connor 2012: 503.

Propsilocerus saetheri Wang, Liu et Paasivirta, 2007: 310 ; Ashe & O’Connor 2012: 503. Syn. nov.

Material examined. Russia: 2 adult males (paratypes), Eastern Siberia, Krasnoyarsk Territory, 10 km North of Norilsk Airport, Alykel station , nameless lake, 69.380287 N, 87.397822 E, 7.VII.1991, leg. N. Zelentzov.

Description

Adult male (n = 2). Total length 5–6 mm. Total length/wing length 1.63–1.96.

Coloration (slide-mounted material). Dark brown.

Head. Eyes bare, reniform. Temporal setae including 10–17 inner verticals (in 2 rows), 4–6 outer verticals and without postorbitals. Clypeus with 20–26 setae. Antenna with 13 flagellomeres and developed plume; terminal flagellomere without subapical setae; AR 1.87–2.2. Palpomeres lengths (in μm): 50–84; 72–96; 132–150; 140–156; 180–200. Palpomeres 1–5 length/head width 1.12–1.15.

Thorax. Antepronotum with 17–26 lateral setae. Acrostichals absent, dorsocentrals 69–89, prealars 49–60, supraalars 1–3, preepisternals 38–65, scutellars 38 – 52; posterior anepisternum II with 6–9 setae. All setae except supraalars arranged in 3–5 rows.

Wing. Length 2.8–3.5 mm, width 0.60–0.80 mm. R and R 1 with 28–56; R 4+5 with 0–2 setae in distal part. Costa extension 120–190 μm long. Anal lobe developed, outline rounded. Squama with 20–35 setae, 88–100 μm long. VR 1.18–1.30.

Legs. Spur of fore tibia 80–96 μm long; spurs of mid tibia 60–66 μm and 63–75 μm; of hind tibia 62–72 μm and 78–102 μm long. Hind tibial comb with 10–11 setae. Lengths and proportions of leg segments as in Table 9.

Hypopygium ( Figs. 49–58 ). Tergite IX with 36–55 long setae and narrow, tapering to pointed apex anal point 76–108 μm long, with 6–7 long lateral setae and 4–6 setae at base ( Figs. 49, 55–56 ). Laterosternite IX with 7–10 setae. Phallapodeme 129–180 μm long; transverse stemapodeme 124–186 μm long, with oral projections ( Fig. 57 ). Gonocoxite 392–432 μm long. Superior volsella as in Fig. 58 , 48 –64 μm long. Inferior volsella as in Figs. 49–50 , 96–228 μm long. Median volsella with rounded base and strong apical spine ( Figs. 51–54 ), 54–88 μm long, sometimes with small tooth in base. Gonostylus with two branches ( Figs. 49–50 ), basal branch 220–228 μm long, inner branch 176–180 μm long; megaseta 16–18 μm long. HR 1.75 –1.78.

Pupa and larva unknown.

Remarks. The description of this species from the Taimyr region was published in Russian ( Zelentzov 2000), and, unfortunately, was not used in the paper of Wang et al. (2007) with description of P. saetheri from Finland. After comparing adult males of P. taimyrus with the description of the P. saetheri , as well as photographs of the hypopygium of this species from Norway, which were kindly provided by Dr. E. Stur, we came to the conclusion that the P. saetheri is a synonym of the P. taimyrus , since the hypopygium of all specimens, as well as other features, are similar, except for the absence of setae in P. satheri on the preepisternum ( Table 10 ), but according to E. Stur (pers. comm.), a male from northern Norway has at least 40 preepisternals.

Distribution. Known from arctic region of East Siberia, Finland and Norway.

Figures

FIGURES 49–58.Adult male of Propsilocerus taimyrus Zelentzov (paratypes).49, hypopygium in dorsal view; 50, hypopygium in ventral view; 51–54, median volsellae; 55–56, anal point; 57, transverse strenapodeme; 58, superior volsellae. Scale bars are 50 μm.

FIGURES 40–48. Adult males of Propsilocerus paradoxus (Lundstrṏm). 40, part of hypopygium in dorsal view; 41, part of hypopygium in ventral view; 42, 45, median volsella; 43, transverse sternapodeme, phallapodeme and aedeagal lobe; 44, gonostylus; 46–47, tergite IX; 48, anal point. Scale bar is 50 μm.