Stegana (Steganina) angustigena, Cheng, Gao & Chen, 2009

Cheng, Yu, Gao, Jian-Jun & Chen, Hong-Wei, 2009, Stegana ornatipes species group from the Oriental Region (Diptera: Drosophilidae), Zootaxa 2216 (1), pp. 37-48 : 41-42

Stegana (Steganina) angustigena sp. nov.

( Figs 7–10 )

Specimens examined. Holotype: ♂ ( SCAU, No. 120621), CHINA: Jianfengling, Ledong , Hainan, 18°41' N, 108°52' E, altitude 700 m, 19.v.2004, on tree trunks, HW Chen . Paratypes: CHINA: 6♂ 10♀ (3♂ 5♀ in KIZ; 3♂ 5♀ in SCAU, Nos 120692-99), same data as holotype except for 20.iv.2008, XP Chen, JJ Gao ; 2♂ 3♀ ( SCAU, Nos 120622-26), Wuzhishan , Hainan, 18°48ʹ N, 109°19ʹ E, altitude 440 m, 20.iv.2007, on tree trunks, HZ Cao, T Li ; 1♂ ( SCAU, No. 120627), Nonggang, Chongzuo , Guangxi, 22°33ʹ N, 106°92ʹ E, altitude 230 m, 23.viii.2004, on tree trunks, HW Chen ; 4♀ ( KIZ), Menglun, Xishuangbanna , Yunnan, 21°41' N, 101°25' E, altitude 880 m, 16–19.iv.2007, ex tussock, JJ Gao ; 3♂ 14♀ (1♂ 1♀ on tree trunks) (1♂ 6♀ in KIZ; 1♂ 6♀ in SCAU, Nos 120628-34, 1♂ 2♀ in SEHU), Mengla, Xishuangbanna , Yunnan, 21°28' N, 101°38' E, altitude 600 m, 21–24.iv.2007, ex tussock, HW Chen, JJ Gao, F Zhao .

Diagnosis. Surstylus strongly curved submedially ( Fig. 8 ); aedeagus composed of 1 lobe-like and 1 pair of slender, rod-like processes; the lobe-like process bifurcated distally, with pubescence ( Fig. 10 ).

Description. Male and female: Pedicel brown; first flagellomere black. Palpus black. Mesonotum brown to dark brown, without stripe. Scutellum dark brown to black. Katepisternum brown on upper part, yellow on lower part. Legs white-yellow, brown on apical part of fore femur, dark brown to black medially on mid and hind femora, with 2 dark brown rings on all tarsomeres. Fore femur with 4–5 setae on distal part of ventral surface. All abdominal tergites and sternites dark brown to black. Male terminalia: Epandrium with approximately 30 setae near posterior to ventral margin on each body-side ( Fig. 7 ). Cercus lacking pubescence ( Fig. 7 ). Plate between hypandrium and aedeagus slightly pubescent ( Fig. 10 ).

Measurements. BL = 2.25 mm in holotype (range in 4♂ 5♀ paratypes: 2.13–2.47 mm in ♂, 2.28–2.91 mm in ♀); ThL = 1.13 mm (1.00– 1.22 mm in ♂, 1.09–1.38 mm in ♀); WL = 1.84 mm (1.74–1.90 mm in ♂, 1.88–2.28 mm in ♀); WW = 1.00 mm (0.98–1.24 mm in ♂, 1.04–1.26 mm in ♀). Indices: arb = 8/6 (7–9/6–7), avd = 0.86 (0.67–0.82), adf = 1.27 (1.36–1.80), flw = 1.91 (1.80–2.10), FW/HW = 0.34 (0.33–0.40), ch/o = 0.06 (0.06–0.09), prorb = 1.28 (1.05–1.25), rcorb = 0.78 (0.71–0.94), vb = 0.21 (0.20–0.33), dcl = 0.40 (0.38– 0.47), presctl = 0.54 (0.47–0.61), sctl = 1.29 (1.46–1.72), sterno = 0.81 (0.80–0.93), orbito = 2.50 (2.00–2.50), dcp = 0.20 (0.16–0.24), sctlp = 1.06 (0.94–1.18), C = 1.89 (1.78–2.12), 4c = 1.33 (1.17–1.37), 4v = 1.81 (1.68–1.81), 5x = 1.30 (1.08–1.30), ac = 9.33 (7.50–10.00), M = 0.62 (0.52–0.62), C3F = 0.69 (0.56–0.73).

Distribution. China (Guangxi, Hainan, Yunnan).

Etymology. A combination of the Latin words: angustus and gena, referring to the narrow gena.

Figures

FIGURES 7–10. Stegana (Steganina) angustigena sp. nov., ♂: 7. Epandrium, surstylus and cercus (lateral view); 8. surstylus (frontal view); 9. 10th sternite; 10. hypandrium, gonopods, aedeagus and aedeagal apodeme (ventral view) (For abbreviations see Figures 1–6. Scale bars: 0.1 mm).