Key to Thailand species of Ophiomyia

1. Calypter with fringe white............................................................................... 2

- Calypter with fringe black...............................................................................4

2. Vibrissal fasciculus developed in male..................................................................... 3

- Vibrissal fasciculus lacking; frons as wide as eye; gena 1/10–1/20 as high as eye, with normal vibrissa on anterior angle; ultimate section of CuA1 2/3 as long as penultimate section (Orient, Pacific, Australia, South Africa; host plant: Vernomia cinerea)................................................................................ O. atralis (Spencer, 1961)

3. Facial carina narrow but distinct; frons subequal to width of eye; gena 1/4 as high as eye; ultimate section of CuA1 about 3/5 as long as penultimate section; distiphallus bulbous distally (Spencer 1977: figs 91, 92) (Orient, Pacific, Australia; Japan; host plants: Goodenia, Scaevola spp.)..................................................... O. cornuta Meijere (1910)

- Facial carina broad, spindle-shaped below antennal bases; frons 1.5 times as wide as eye, gena 1/5 as high as eye; ultimate sec- tion of CuA1 as long as penultimate; distiphallus striated distally.................................. O. striata sp. nov.

4. Small species, with wing length 1.3–1.5 mm; vibrissal fasciculus present in male; gena 1/5–1/7 as high as eye; ultimate section of CuA1 almost equal to penultimate section; surstylus with nine spines; distiphallus with a clavate processs on inner left side (Taiwan, Thailand).......................................................... O. setituberosa Sasakawa (1972)

- Larger, wing length 1.6–2.9 mm; vibrissal fasciculus absent in male............................................. 5

5. Wing less than 2.5 mm in length; gena narrow, 1/6–1/8 as high as eye............................................ 6

- Wing length 2.5–2.9 mm; gena 1/5 as high as eye; ultimate section of CuA1 1/2 as long as penultimate (Orient; Japan; fruit- feeder of Ricinus sp.)................................................................ O. ricini (Meijere, 1922)

6. First antennal flagellomere with long pile; surstylus with about 35 spines; hypandrium with basal apodeme long; distiphallus with more than 65 strong spines on one membranous side (Orient, Australia; Japan).......... O. conspicua (Spencer, 1961)

- First antennal flagellomere minutely pilose................................................................. 7

7. Basiphallus with lateral sclerites connected broadly at middle.................................................. 8

- Basiphallus with lateral sclerites largely isolated............................................................. 10

8. Fore tibia with an external bristle; surstylus with about 50 spines; distiphallus with spinulose lobes laterally (Thailand, Vanu- atu)......................................................................... O. phalloides Sasakawa (2004)

- Fore tibia without external bristle......................................................................... 9

9. Ocellar triangle with ventral tip extending to level of second ors; face with carina narrowly distinct, extending to oral margin; surstylus with about 28 spines; distiphallus with whip-like process on left lateral lobe.............. O. flagellata sp. nov.

- Ocellar triangle with ventral tip extending almost to level of first or i; face without distinct carina; distiphallus broadened dis- tally (Orient, Pacific, Australia, Africa; Japan; stem-miner on Glycine, Phaseolus spp. etc.)....... O. phaseoli (Tryon, 1892)

10. Surstylus with spines more than 30....................................................................... 11

- Surstylus with 15–17 spines; distiphallus with basal lobe surrounding as ring and spinulose on lateral side (Orient, Australia, Africa; Japan; stem-miner on Glycene, Phaseolus spp. etc.).......................... O. centrosematis (Meijere, 1940)

11. Distiphallus with lobe sparsely spinulose (Orient, Australia)................................ O. rotata (Spencer, 1965)

- Distiphallus with four lobes, dorsal lobe smaller than ventral lobe, spinulose internally.............. O. quadrifida sp. nov.