Zygoneura (Pharetratula) bidens (Mamaev, 1968)

Pharetratula bidens Mamaev, 1968: 610 –611.

Pharetratula sinica Zhang & Yang, 1990: 267 .

Zygoneura (Pharetratula) bidens (Mamaev, 1968); Menzel & Mohrig, 2000: 585.

Specimens examined. 2 Males, China, Heilongjiang province, Mt. Maoershan nature reserve, 45°15΄N, 128°13΄E, 26.VII.2008, Su-Jiong Zhang [SM00188–00189]. 1 Male, Inner Mongolia, Zhuozi, Baoan- Linchang, 21.VIII.1987, Chi-kun Yang.

Remarks. This species was first recorded in Ussurijsk, Russia (Mamaev 1968) and found in China (Heilongjiang, Inner Mongolia). It can be distinguished by a gonostylus with two subapical megasetae on the short dorsal lobe, subequal in length and close to each other (Menzel & Mohrig 2000).

Menzel & Mohrig (2000) synonymized Pharetratula sinica Zhang & Yang, 1990 with Z. bidens without explanation. The holotype of the species is in poor condition and the diagnostic characters were difficult to examine. However, the figure plates prepared by Zhang & Yang (1990) show the hook-like apex of the gonostylus, which is strongly attenuated and curved, while the gonostylus of Z. bidens is nearly oval, not attenuated but faintly curved. Therefore, we suspect they may represent two different species.