Key to males of Chinese species of Haploperla
1. Epiproct with an acute apex............................................................................. 2
-. Epiproct with a bluntly rounded apex...................................................................... 5
2. Medial sclerotized area of tergum 10 pale and not distinct........................................ H. ussurica Navás
-. The sclerotized area of tergum 10 distinct.................................................................. 3
3. Head and pronotum almost pale only with a pale brown area covering ocelli (Fig. 1)................ H. tuanjiena sp. nov.
-. Head and pronotum with distinct dark pigment.............................................................. 4
4. Tergum 9 with a spinous posterior lobe...................................................... H. choui Li & Yao
-. Tergum 9 without posterior lobe................................................. H. lepnevae Zhiltzova & Zwick
5. Epiproct mostly sclerotized and without hair............................................ H. triangulata Chen & Du
-. Epiproct with sclerotized margins, membranous posterodorsally with sparse patch of setae........................... 6
6. Tergum 9 with a posterior lobe; epiproct with a rounded tip (Figs. 12, 14)...................... H. datongensis sp. nov.
-. Tergum 9 without posterior lobe; epiproct tip narrow.................................... H. valentinae Stark & Sivec