Beckidia tethys (Townes)

Zorina, Oksana V., 2006, New species and records of Beckidia Saether (Diptera: Chironomidae) from the Russian Far East, Zootaxa 1151, pp. 47-53 : 52-53

Beckidia tethys (Townes)

( Figs. 6–7 )

Harnischia (Cladopelma) tethys Townes, 1945: 152 , fig. 174. Beckiella tethys (Townes) ; Saether, 1977: 120, fig. 44.

Beckidia tethys (Townes) ; Saether, 1979: 119; Cranston et al. 1989: fig. 10.6; Makarchenko et al. 2005: 394.

Material examined: 1 male, RUSSIA, Khabarovsk Territory, Ussury River near Zabaykalskaya Village, 25.vii.2003, T. Tiunova; 1 male, Primorye Territory, Khanka Lake near Astrakhanka Village, 26.viii.1996, E. Makarchenko; 3 males, Khanka Lake near Turiy Rog Village, 12.vi.1998, T. Vshivkova.

Previous descriptions of B. tethys are brief, so below I give a more detailed description based on the specimens from the Russian Far East.

Male (n = 3)

Total length 3.0– 3.3 mm. Wing length 1.3–1.4 mm. Total length/wing length 2.1–2.5.

Coloration. Scapus yellowish, flagellomeres dark brown; ground color of thorax pale yellow, mesonotal strips and two­third of postnotum yellowish brown; front leg brownish except for pale yellow femur; mid and hind legs with pale yellow femur and tibia, ta1–5 gradually darker toward apex; abdomen yellowish.

Head. Frontal tubercle absent. Verticals 8–11. Clypeus with 6–8 setae. Antenna 895– 916 m long, AR 1.63–1.82. Maxillary palp 440 m long, lengths of segments II­V (in m): 40, 80, 110–130, 190. Palp length/head width 0.85, antenna length/palp length 2.03.

Thorax. Antepronotals 0, acrostichals 0, dorsocentrals 6–8, prealars 2–3, supraalars 1. Scutellum with 3–8 setae.

Wing. Width 0.43 mm. VR 1.03–1.22. R with 2–4 setae, R1 without setae, R4+5 with 2 apical setae, brachiolum with 2 setae. Squama with 2–5 setae.

Legs. Combs of median and hind tibiae with 2 spurs, 18–23 m long. LR1 1.94­2.0, LR2 0.64, LR3 0.73; SV1 1.37–1.38, SV2 3.36, SV3 2.64; BV1 1.67–1.69, BV2 3.21, BV3 2.22; BR1 2.89–3.13, BR2 5.0, BR3 5.0.

Hypopygium ( Figs. 6–7 ). Anal tergite bands of H­type. Anal point 50–70 m long, 9 m wide, placed preapically on tergite IX. Laterosternite IX with 1–2 setae. Transverse sternapodeme 41–45 m long. Gonocoxite 90–95 m long, with 3–4 setae. Superior volsella pad­like, 32 m long, 32–36 m wide, with 11–15 setae and microtrichia, partially fused with inferior volsella. Gonostylus 126–153 m long, 23–27 m wide, curved, widest medially. HR 0.63–0.66.

Distribution

The species has previously been recorded from Canada and USA in the Nearctic Region and from Serbia in the Palaearctic Region ( Saether et al. 2000). The species is recorded for the first time from Russia.

Figures

FIGURES 1 – 7. Male imagines of Beckidia biraensis new species (1 – 2), Beckidia connexa new species (3 – 5) and Beckidia tethys (Townes) (6 – 7). 1, 3, 6. Hypopygium. 2, 5, 7. Superior and inferior volsella. 4. Anal point. Scale bars: 50 m.