Pseudodiamesa (s. str.) gorodkovi Makarchenko, 1909

Makarchenko, Eugenyi A., 2022, Redescription of two little-known Palaearctic species of Pseudodiamesa Goetghebuer (Diptera: Chironomidae: Diamesinae), Zootaxa 5092 (5), pp. 596-600 : 596-598

Pseudodiamesa (s. str.) gorodkovi Makarchenko

( Figs. 1–5 )

Pseudodiamesa (s. str.) gorodkovi Makarchenko, 1983: 1909 ; Ashe & O’Connor 2009: 304.

Material examined. Holotype: adult male, Russia, Karachay-Cherkess Republic , Caucasus Mountains, Teberda Nature Reserve, alt. 1300 m above sea level, 17.III.1964, leg. K. Gorodkov. Paratypes: 4 adult males, same data as holotype ; 1 adult male, same data as holotype, except 25.XII.1959, leg. L. Arens.

Adult male (n = 3).

Total length 6.1–7.0 mm. Wing length 5.8–6.0 mm. Total length/wing length 1.0–1.16.

Coloration. Head, thorax, legs, and abdomen dark brown to black; antennae brown to dark brown; wings greyish.

Head. Eyes bare and extended dorsomedially. Temporal setae including 14–16 preoculars, 8–14 verticals and 8–10 postorbitals. Clypeus with 41–48 setae. Antenna with 13 flagellomeres and developed plume, setae of which 525–1689 μm long; pedicel without setae; terminal flagellomere with 1 subapical setae 64–72 μm long; AR 3.96–4.40. Palpomere lengths (in μm): 44–50; 186–193; 294–300; 248–252; 280–290. Palpomere 3 distally with sensilla capitata (diameter 16–20 μm). Palpomeres 1–5 length/head width 1.01–1.11.

Thorax. Antepronotum with 20–22 lateral setae. Acrostichals absent, dorsocentrals 38–43 (in 2 rows in anterior 2/3 and in 3 rows in posterior 1/3), prealars 51–56 (in 2–3 rows), scutellars ca 60–67.

Wing. Length 5.8–6.0 mm; width 1.40–1.44 mm. Membrane without setae. R and R 1 with 9–12 setae, R 4+5 with 2 setae on apex. Costa extension 150–160 μm long. RM length/MCu length 2.0–2.3. Anal lobe developed, outline rounded.

Squama with ca 80–90 setae, 164–197 μm long, in 2 rows. VR 0.90–0.91.

Legs. Spur of fore tibia 136–172 μm long; spurs of mid tibia 96–113 μm and 92–101 μm; of hind tibia 140–143 μm and 76–101 μm long. Hind tibial comb with 12–16 setae. Lengths and proportions of leg segments as in Table 1 .

Hypopygium ( Figs. 1–5 ). Tergite IX with 16–28 setae on each side, 56–68 μm long. Anal point wide in basal part, tapering to pointed apex, 168–170 μm long ( Figs. 1–3 ). Laterosternite IX with 16–22 setae. Gonocoxite 520–525 μm long; basal lobe of small size, rounded, with some long setae at inner part ( Figs. 1, 3, 5 ). Gonostylus 358–361 μm long, massive, in dorsal view with large lobe on the outer edge and with small triangular tubercle in the basal part along the inner edge ( Figs. 1–3 ); shape in ventral view as in Fig. 4 ; apically with small tooth, megaseta absent. HR 1.45–1.63. Transverse sternapodeme 260 μm long and 96–100 μm wide, with short rod-like oral projections, anterior margin slightly concave ( Fig. 5 ). Phallapodeme with lateral aedeagal lobe 184–192 μm long, which more wide in basal 1/4 and narrow in distal 3/4, elongated in rounded apex ( Fig. 5 ).

Pupa and larva unknown.

Remarks. I include this species in the nivosa group. The original description ( Makarchenko 1983) did not contain data on the shape and structure of the transverse sternapodeme. Namely, these characters are present only in P. (s. str.) gorodkovi and are absent in other representatives of the genus. Also, this species differs from the known members of Pseudodiamesa by a short massive gonostylus with a large lobe along the outer edge and some other features specified in this redescription.

Distribution. Known only from type locality in Teberda Nature Reserve of the North Caucasus.

Figures

FIGURES 1–5. Male of Pseudodiamesa (s. str.) gorodkovi Makarchenko. 1, 3, hypopygium in dorsal view; 2, gonostylus in dorsal view; 4, gonostylus in ventral view; 5, transverse sternapodeme, lateral aedeagal lobes and basal lobe of gonocoxite.