Chrysosoma vietnamense, Wang & Zhang & Yang, 2012

Wang, Jinjing, Zhang, Lili & Yang, Ding, 2012, Chrysosoma from Vietnam, with description of a new species and a key to Vietnamese species (Diptera: Dolichopodidae), Zootaxa 3382 (1), pp. 53-58 : 53-54

Key to males of Chrysosoma species from Vietnam

1 Wing nearly hyaline, lacking spots ( Figs. 7–10 ); antenna blackish or black; ventral bristles on fore femur pale yellow...... 2

- Wing with very large dark brown spots ( Fig. 6 ); antenna dark yellow; ventral bristles on fore femur black............... 5

2 Fore coxa yellow, mid and hind coxae black; all femora yellow................................................. 3

- All coxae and femora black............................................................................. 4

3 Crossvein m-cu nearly straight ( Figs. 3 , 8 ); male arista simple apically; male cercus furcate...................................................................................................... Chrysosoma hangzhouense Yang

- Crossvein m-cu distinctly bent ( Figs. 2 , 7 ); male arista apically weakly swollen and pale; male cercus long, finger-like.................................................................................... Chrysosoma hainanum Yang

4 Abdomen without modified hairs ( Fig. 4 ); first flagellomere more than two times longer than wide; fore tibia without dorsal setae on basal half; male cercus with ventral arm not bifurcated apically............. Chrysosoma shixingense Zhu et Yang

- Abdominal tergites 1–5 with long dense white hairs at lateral margin ( Fig. 5 ); first flagellomere less than 1.5 times longer than wide; fore tibia with 3 long dorsal setae on basal half; male cercus with ventral arm bifurcated apically ( Fig. 11 )..................................................................................... Chrysosoma vietnamense sp. nov.

5 Mesonotum without dark longitudinal stripes; ventral arm of cercus not furcated apically ( Fig. 1 ).................................................................................................... Chrysosoma cupido (Walker)

- Mesonotum with three dark longitudinal stripes; ventral arm of cercus shallowly furcated apically.............................................................................................. Chrysosoma vittatum (Wiedemann)

Figures

FIGURES 6–11. Wings (male) and male terminalia. 6, Chrysosoma cupido (Walker); 7, C. hainanum Yang; 8, C. hangzhouense Yang; 9, C. shixingense Zhu and Yang; 10, C. vietnamense sp. nov. Figs. 6–10, scale bars = 1 mm. 11, C. vietnamense sp. nov. (male terminalia), lateral view, scale bar = 0.25 mm. Abbreviations: cer = cercus; epn = epandrium; epnl = epandrial lobe; hyp = hypandrium; hypl = hypandrial lateral arm; ph = phallus; sur = surstyllus.

FIGURES 1–5. Male habitus photographs. 1, Chrysosoma cupido (Walker); 2, C. hainanum Yang; 3, C. hangzhouense Yang; 4, C. shixingense Zhu and Yang; 5, C. vietnamense sp. nov. Scale bars = 1 mm.