Stegana (Steganina) arcygramma, Chen, Xi-Peng & Chen, Hong-Wei, 2008

Chen, Xi-Peng & Chen, Hong-Wei, 2008, The Stegana coleoptrata species group (Diptera: Drosophilidae) from mainland China, Zootaxa 1891, pp. 55-65 : 61-62

Stegana (Steganina) arcygramma sp. nov.

( Figs 25–30 )

Specimens examined. Holotype ɗ (SCAU, No. 120297): CHINA – labelled “Menglun, Xishuangbanna, Yunnan, 21°41' N, 101°25' E, 700 m a.s.l., 12.ix.2002, on tree trunk, H.W. Chen”. Paratypes: 1Ψ (SCAU, No. 120298), same data as holotype; 1ɗ1Ψ (SCAU, No. 120299 -300), Mengla, Xishuangbanna, Yunnan, 21°28' N, 101°38' E, 600 m a.s.l., on tussock, 23.iv.2007, J. J. Gao.

Etymology. A combination of the Greek words “arcy” + “gramma”, referring to the scutum with longitudinal markings laterally.

Diagnosis. Aedeagus strongly, roundly expanded ( Figs. 28, 29 ); gonopods roundly protruded dorso-medially, with 1 cuneal projection on posterior surface ( Fig. 30 ).

Description. Male and female: Frons yellow, black below ocellar triangle and lower margin (above ptilinal fissure), lacking minute setulae. First flagellomere yellow on basal half, black on distal half. Face yellow, black on lower margin; facial carina absent. Clypeus black medially, brown laterally. Palpus black. Gena black; postgena brown. Scutum yellow with 1 broad dark brown longitudinal stripe medially in male and female, 1 brown longitudinal stripe (interrupted at transverse suture) sublaterally and 2 black patches each on upper parts of postpronotum and supra-alar area in male, brown longitudinal markings laterally in female (like as in Stegana (Steganina) ctenaria Nishiharu, 1979 ). Mesopleuron with 1 black longitudinal stripe above (running from propleuron to the base of halter), but interrupted medially in male. Katepisternum white-yellow on lower part, brown on upper part. Scutellum black, yellow at tip. Wing dark brown to black anteriorly, slightly pale posteriorly, white-yellow at tip. Legs dark brown, grey-yellow on all tarsi and apical parts of all tibiae. Fore femur with 6-8 suberect setae on distal part of ventral surface. Abdominal tergites brown medially, with yellow patches on lateral margins of 2nd to 4th tergites. Male terminalia: Epandrium with ca. 27 setae on dorsal to posterolateral portion per side, strongly narrowed ventrally ( Fig. 25 ). Surstylus incurved and somewhat concave apically, with numerous serrated, minute processes ( Fig. 26 ). Tenth sternite protruded posteriorly, with 2 acute projections (one each side) dorso-laterally ( Fig. 27 ). Paramere undistinguishable. Aedeagus without tentacle-like setae ( Figs. 28, 29 ).

Measurements. BL = 3.50 mm in holotype (range in 1ɗ and 3Ψ paratypes: 3.56–4.20); ThL = 2.09 mm (1.73–2.15); WL = 3.28 mm (3.40–3.70); WW = 1.70 mm (1.48–1.75). Indices: arb = 12/8 (10/7–12/8), avd = 0.75 (0.68–0.72), adf = 1.82 (1.50–2.00), flw = 2.18 (2.00–2.20), FW/HW = 0.41 (0.41–0.45), ch/o = 0.16 (0.15–0.17), prorb = 1.08 (1.19–1.38), rcorb = 0.73 (0.67–0.89), vb = 0.35 (0.30–0.40), dcl = 0.55 (0.43– 0.58), presctl = 0.82 (0.70–0.85), sctl = 1.55 (1.35–1.52), sterno = damaged (0.88–0.96), orbito = 1.88 (1.75– 2.33), dcp = 0.19 (0.21–0.22), sctlp = 1.50 (1.54–1.92), C = 2.26 (2.18–2.27), 4c = 1.09 (1.03–1.13), 4v = 1.91 (1.75–1.83), 5x = 1.42 (1.25–1.55), ac = 11.67 (10.67–12.33), M = 0.53 (0.48–0.57), C3F = 0.69 (0.68–0.79).

Figures

FIGURES 25 – 30. Stegana (Steganina) arcygramma sp. nov., male genitalia: 25. epandrium, surstylus and cercus; 26. surstylus; 27. 10 th sternite; 28. hypandrium, paramere, aedeagus and aedeagal apodeme; 29. ditto; 30. gonopods (For orientation, abbreviations and scale lines see Figs. 1 – 6).