Key to species of genus Balala (males)

1 Scutellum apex not extended to apex of clavus, centre compressed vertically into keel, subapex truncate in lateral view (Figs. 4B, D, 8A, C)........................................................................................ 2

- Scutellum apex reaching apex of clavus, centre moderately swollen, gradually declined toward apex in lateral view (Figs. 1A, B, 2C, D, 5A, D, 6A, B, 9A, B, H, I)...................................................................... 3

2 Crown anterior margin slightly angulate, three tubercles at apex (Fig. 4C), pygofer ventral appendage with apical 2/5 strongly recurved, hook-like (Fig. 4F)..................................................................... B. curvata

- Crown anterior margin round, without tubercle at apex (Fig. 8A), pygofer ventral appendage gradually curved dorsad, not hooklike (Fig. 8G)......................................................................... B. hainana sp. nov.

3 Aedeagus shaft without process, pygofer ventral appendage with apex curved backward (Figs. 1D, H)........ B. fulviventris

- Aedeagus shaft with one or more processes, pygofer ventral appendage with apex curved dorsad (Figs. 3C, E, 5H, J, 7I, L, 10C, G, 11F, H)........................................................................................... 4

4 Aedeagus shaft with pair of slender furculae at apex (Figs. 10F, 11I), pygofer ventral appendage with one small preapical tooth (Figs. 10C, 11E)...................................................................................... 5

- Aedeagus shaft without furculae at apex (Figs. 3A, 5H, 7I), pygofer ventral appendage tapering to tip, without small preapical tooth (Figs. 3F, 5J, 7B)................................................................................. 6

5 Aedeagus shaft with pair of small horn-like processes present on basal part of dorsal surface submedially (Fig. 10I)............................................................................................. B. karenia sp. nov.

- Aedeagus shaft without any process on dorsal surface (Fig. 11J)................................ B. mekongia sp. nov.

6 Frontoclypeus and anteclypeus dark or not (Figs. 5F, 6D), aedeagus shaft wide and flat, with pair of lateral subapical processes, lateral margin serrate in front of lateral process (Figs. 5H, 7 G–I)................................................ 7

- Frontoclypeus and anteclypeus dark (Fig. 2B), aedeagus shaft tubular without lateral subapical process, lateral margin not serrate (Figs. 3A, C)............................................................................ B. nigrifrons

7 Aedeagus with median longitudinal ridge very strong through entire shaft, lateral process keen-edged, gonopore truncate and subapical on ventral surface (Figs. 5G, H)............................................................... B. lui

- Aedeagus shaft without median longitudinal ridge, lateral process short and blunt, gonopore round on apex (Figs. 7G, I)......................................................................................... B. fujiana sp. nov.