Rheochlus wirthi (Freeman, 1961)

Siri, Augusto, Brodin, Yngve, Ilpla, Conicet-Cct & Unlp, 2014, Cladistic analysis of Rheochlus and related genera, with description of a new species (Diptera: Chironomidae: Podonominae), Acta Entomologica Musei Nationalis Pragae 54 (1), pp. 361-375 : 370

Rheochlus wirthi (Freeman, 1961)

( Figs 16–19 )

Material examined. 2 adult JJand 2 adult ♀♀, “ AUSTRALIA / Narrabeen / Middle Creek / New South Wales / September 1956 / W. W. Wirth leg” ( SMNH).

Redescription. Male imago (n = 1–2) ( Figs 16–17 ). Total length 1.34–1.53 mm, total length / wing length 1.29–1.54.

Head. Eyes hairy. Antenna with 14 flagellomeres ( Fig. 16 ). AR 0.40. Temporals and postorbital setae could not be counted. Clypeus with 2 setae. Palpomere lengths (I–V): 10–12; 13–15; 20; 15–20; 30. Tentorium 70 long.

Thorax. Setae could not be counted.

Wing ( Fig. 17 ): length 0.99–1.35 mm; width 0.37 mm; L/ W 2.68 –2.80. VR 0.88–0.92. Width of cell r 1 at the end of vein R 1 80–83 ; maximum width of cell r 5 115–130; r 1 /r 5 0.62–0.72. Brachiolum with 2–3 setae; squama with 1–2 setae. R with 0–1 setae, R 1 with 2–3 setae, R 4 +5 with 1 seta. Remaining veins bare .

Legs. Spur of front tibia 25–28 long; spurs of mid tibia 15 and 20 long; of hind tibia 15 and 48–50 long. Apex of ti 1 32 wide; of ti 3 34 wide. Comb with 9–12 spines. Lengths and proportions of legs in Table 3.

Hypopygium. Setae on tergite IX could not be counted, laterosternite IX with 2 setae. Phallapodeme 45 long; transverse sternapodeme 65 long. Gonocoxite 75 long; short basal keel 0.43 (1) as long as gonocoxite. Gonostylus 45 long; apical lobe 17 long, apical seta (“t” seta) 7 long; subapical lobe 10 long, with apical seta (“t” seta) 9 long. Seta “p” 35 long, 3 wide, L/W of seta “p” 11.7. The “x” and “y” setae discernible. The “y” seta close to the base of the apical lobe, clearly proximal to the “x” seta. HR 1.67, HV 2.03.

Female imago (n = 1–2) ( Figs 18–19 ). Total length 1.45 mm. Total length / wing length 1.39. Wing length / profemur length 3.64–4.00.

Head. Eyes hairy. Antenna with 13 flagellomeres ( Fig. 18 ). Last flagellomere 55 long, almost as long as flagellomeres 8–12 together. Flagellomeres 2–12 short, almost as long as wide. AR 0.25. Temporal setae 4; postorbitals 3 on each side; clypeals 2. Palpomere lengths (I–V): 8; 15; 18; 20; 25. Tentorium 63 long.

Thorax. Setae could not be counted.

Wing ( Fig. 19 ): length 1.02–1.04 mm; width 0.41–0.42 mm; L/ W 2.4 –2.5. VR 0.88–0.91. Width of cell r 1 at the end of vein R 1 90 ; maximum width of cell r 5 133; r 1 /r 5 0.68. Brachiolum with 0? setae; squama with 0? setae. R with 2 setae, R 1 with 4–5 setae, R 4 +5 with 3–7 setae. Remaining veins bare. C extension 50–63 long .

Legs. Spur of front tibia 20–23 long; spurs of mid tibia 20 and 10–13 long; of hind tibia 46–48 and 15 long. Apex of ti 1 24 wide; of ti 3 40 wide. Comb with 9–11 spines. Lengths and proportions of legs in Table 4.

Genitalia. Cercus 30 long; noto plus ramus 150 long. Seminal capsule 40 long. Sternite VIII with 16 setae. Tergite IX with 8 setae, plus 4 lateral setae.

Distribution. Australia (New South Wales: Narrabeen).

Figures

Figs 10–19. Rheochlus species adults. 10–12 – R. insignis Brundin, 1966, male: 10 – antenna; 11 – wing; 12 – hypopygium, dorsal view (right) and ventral view (left). 13–14 – R. insignis Brundin, 1966, female: 13 – antenna; 14 – wing. 15 – R. prolongatus Brundin, 1966, male wing. 16–19 – R. wirthi (Freeman, 1961): 16–17 – male (16 – antenna, 17 – wing); 18–19 – female (18 – antenna, 19 – wing). Scale bars = 100 ȝm.