Key to Chinese species of genus Wesmaelia

1. Distal 1/5 of vein R1 and vein SR1+3-SR shortened and not meeting each other apically (Fig. 7)...................... 2

- Distal end of vein R1 and vein SR1+3-SR evenly sclerotized and meeting each other apically; Taiwan, Fujian........................................................................................ W. petiolate (Wollaston, 1895)

2. Last flagellomere not elongate in female but thickened club-form, penultimate flagellomere also somewhat thickened; first flagellomere 4.0 × longer than broad apically, further flagellomeres gradually shortening; eye 1.8 × as long as temple in dorsal view; notauli deep and narrow; ovipositor sheath in lateral view as long as third segment of hind tarsus; Taiwan ..................................................................................... W. decurta Papp & Chou, 1995

- Last flagellomere elongate in female, last two flagellomeres not thickened (Fig. 2); first flagellomere 5.5 × longer than broad apically, further flagellomeres not gradually shortening; eyes 1.4 × as long as temple in dorsal view (Fig. 3); notauli shallow and wide (Fig. 5); ovipositor sheath in lateral view 1.9 × the length of third segment of hind tarsus (Fig. 10); Yunnan .......................................................................................... W. longius Li, sp. n.