|
| (1) Antenna with 12 flagellomeres | 2 |
| Antenna with 13 flagellomeres | 6 |
| (2) Apical lamellae of median volsella bulbous, Oriental China | bullus Wang & Guo |
| Apical lamellae of median volsella not bulbous | 3 |
| (3) Apex of anal point broad, India, Malaysia | madarihatensis Kyerematen, Andersen & Sæther |
| Apex of anal point narrow | 4 |
| (4) Anal tergite bands nearly horizontal, Oriental China | polychaetus Wang & Guo |
| Anal tergite bands V-shaped | 5 |
| (5) Anal tergite with narrowly interrupted basal band, Malaysia | kuantanensis Kyerematen, Andersen & Sæther |
| Anal tergite without basal band, India | nudicornus n. sp. |
| (6) Median volsella long, reaching beyond apex of inferior volsella | 7 |
| Median volsella short, not reaching beyond apex of inferior volsella | 10 |
| (7) Median volsella apically with two distinct plates, Indonesia | adjectus (Johannsen) |
| Median volsella with distal lamellate apical setae never fused into plate | 8 |
| (8) Anal tergite band V-shaped, Thailand, Australia | oss Cranston |
| Anal tergite band transverse | 9 |
| (9) Anal tergite band separate; median volsella conspicuously slender, Thailand | minusculus Kyerematen, Andersen & Sæther |
| Anal tergite band medially fused; median volsella not slender, Oriental China, Ghana | buculicaudus Kyerematen in Kyerematen, Andersen & Sæther |
| (10) Posterior margin of tergite IX with projections or shoulders to each side | 11 |
| Posterior margin of tergite IX triangular, rounded, or at most straight | 13 |
| (11) Tergite IX posterior margin with well-developed projections; gonostylus abruptly tapered | 12 |
| Tergite IX posterior margin without such projections, but with distinct shoulders, gonostylus not abruptly tapered, Indonesia, Australia | trivittatus (Johannsen) |
| (12) Inferior volsella hand shower shaped; basal anal tergite band joined medially, India | caputimberus n. sp. |
| Inferior volsella not as above, basal anal tergite band interrupted, Indonesia | additus (Johannsen) |
| (13) Digitus well developed, extending beyond margin of superior volsella | 14 |
| Digitus small or absent, not extending beyond margin of superior volsella | 21 |
| (14) Median volsella not reaching apex of superior volsella; if gonostylus abruptly tapering distally, then apical portion parallel-sided and straight | 15 |
| Median volsella at least reaching apex of superior volsella; if gonostylus abruptly tapered, then apical portion not parallel-sided and straight | 20 |
| (15) Superior volsella knob- or hook-like posterior extension | 16 |
| Superior volsella rounded, ovoid, oblong or thumb-like | 18 |
| (16) Superior volsella with posterior extension knob-like, Thailand | orientalis Moubayed |
| Superior volsella with posterior extension hook-like | 17 |
| (17) Superior volsella greatly hooked; apical setae of superior volsella not fused into plate; Thailand, Lebanon, Europe | reissi Lehmann |
| Superior volsella slightly hooked; apical setae of superior volsella fused into plate; Oriental and Palaearctic China, Europe, North Africa and Canada | muscicola Thienemann |
| (18) Anal point tapering; Oriental Japan | amamiflavus Sasa |
| Anal point spatulate | 19 |
| (19) Superior volsella rectangular with rounded margin; basal tergite band medially joined; Oriental China, Palaearctic Japan | tamatertius Sasa |
| Superior volsella rounded; basal tergite band absent; Oriental Japan | okisimplex Sasa |
| (20) Gonostylus abruptly tapered with apical portion curved; superior volsella with large, bluntly rounded apical projection; median volsella apparently without apical plate, India, Indonesia, Oriental China | acerbus Johannsen |
| Gonostylus not abruptly tapered; superior volsella subquandrangular; median volsella with wide apical plate; Palaearctic Japan, Oriental and Palaearctic China | tamaquartus Sasa |
| (21) Abdomen banded; anal point crests long, proximally fused forming an arc; superior volsella rounded; median volsella without plate | 22 |
| Abdomen not banded; hypopygium not with above configuration | 23 |
| (22) Gonostylus not abruptly tapered plate, India, Indonesia, Oriental and Palaearctic Japan, Palaearctic China | aestuarius (Tokunaga) |
| Gonostylus abruptly tapered, Oriental China | liuae Wang & Guo |
| (23) Gonostylus more or less abruptly tapered, with distinctly parallel-sided apical portion or with curved apex; superior volsella with pronounced posterior extension; median volsella extending beyond apex of superior volsella | 24 |
| If gonostylus abruptly tapered, then without parallel-sided or curved apex | 25 |
| (24) Gonostylus with apical portion distinctly parallel-sided; superior volsella with posterior extension long, digitiform; Malaysia | phaselus Kyerematen, Andersen & Sæther |
| Gonostylus with apex curved; superior volsella with posterior extension broad and rounded; Thailand | thailandensis Moubayed |
| (25) Anal tergite bands V-shaped and medially joined | 26 |
| If anal tergite bands V-shaped, then not medially joined | 27 |
| (26) Anal point nonspatulate; median volsella extremely beyond apex of superior volsella; AR > 0.60, Indonesia | tobaseptidecimus Kikuchi & Sasa |
| Anal point spatulate; median volsella not extending beyond apex of superior volsella; AR < 0.40, India | spinicornus n. sp. |
| (27) Apex of anal point spatulate; gonostylus tapering abruptly or gradually | 28 |
| Apex of anal point parallel-sided or tapering; gonostylus tapering gradually | 34 |
| (28) Superior volsella with pronounced, hook-like posterior extension, Thailand | falcipedius Kyerematen, Andersen & Sæther |
| Superior volsella rounded or rectangular | 29 |
| (29) Superior volsella rectangular, Oriental China | quadratus Wang & Guo |
| Superior volsella rounded | 30 |
| (30) Gonostylus tapering gradually | 31 |
| Gonostylus abruptly tapered in apical portion | 33 |
| (31) Anal point crests proximally fused, forming an arc, Thailand | beccus Kyerematen, Andersen & Sæther |
| Anal point crest V-shaped | 32 |
| (32) Median volsella reaching beyond apex of superior volsella; basal anal tergite bands absent; Thailand, Lebanon, Europe | curtistylus (Goetghebuer) |
| Median volsella short, not reaching apex of superior volsella; basal anal tergite bands present, Thailand | falcatus Kyerematen, Andersen & Sæther |
| (33) Median volsella recurved; AR about 0.70, Thailand | sessilipersonatus Kyerematen, Andersen & Sæther |
| Median volsella not markedly recurved; AR about 0.40, Thailand | soelii Kyerematen, Andersen & Sæther |
| (34) Median volsella extending beyond apex of superior volsella; anal point crests proximally fused, forming an arc, Thailand | pallidus Kyerematen, Andersen & Sæther |
| Median volsella not reaching beyond apex of superior volsella; anal point crests V-shaped | 35 |
| (35) Anal point broad, parallel–sided; AR about 0.1–0.3, Thailand | koraensis Kyerematen, Andersen & Sæther |
| Anal point lanceolate; AR about 0.3–0.4, Thailand | verticillus Kyerematen, Andersen & Sæther |
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