Key to the South Korean species of Lasiopogon

1. Halter with a distinct black spot; mystax bright white; 7–9 mm ................................. Lasiopogon terneicus

- Halter with/without spot; mystax yellow and black/entirely black ............................................................. 2

2. Halter with black spot; mystax black above, yellow below; 9.5– 11 mm .......................... Lasiopogon leleji

- Halter with/without spot; mystax black....................................................................................................... 3

3. Halter with a diffused brown spot; abdomen shiny black; 8 mm ...................................... Lasiopogon hinei

- Halter wholly yellow, abdomen black/brown/gray...................................................................................... 4

4. Thorax gray; abdomen and wings black; 9–12 mm ....................................................... Lasiopogon rokuroi

- Thorax brown; abdomen gray/brown; wings not distinctly black ............................................................... 5

5. Paramedian stripes distinct brown/black extending to apex of thorax; 7–10 mm ......... Lasiopogon akaishii

- Paramedian stripes less distinct, disappearing apically; large flies 11–14.5 mm ...... Lasiopogon hasanicus