A key to males of all eight Diplonevra species from South Korea

1. Hind tibia with three dorsal longitudinal setal palisades (Fig. 4C)............................................... 2

- Hind tibia with two dorsal longitudinal setal palisades (Fig. 4U)................................................ 3

2. Inner face of hind trochanter without stout setae (Fig. 6B); hind tibia with 3 or 4 anterodorsal stout setae (Fig. 4B); venter of abdomen blackish brown (Fig. 1A)............................................................. D. abbreviata

- Inner face of hind trochanter with one stout seta; hind tibia with one anterodorsal stout seta; venter of abdomen pale yellow (based on Chinese specimens described and illustrated in Liu & Yang 2016: 33, figs. 1, 2, 33)................ D. bifasciata

3. Hind tibia with anterodorsal stout setae (Fig. 4H)............................................................ 4

- Hind tibia without anterodorsal stout setae (Fig. 4K)......................................................... 5

4. Body mostly yellowish brown with dark brown markings on abdominal tergites (Fig. 2I); ventrobasal area of inner face of hind femur with two peg-like strong setae (Fig. 7F); hind tibia with 2 or 3 anterodorsal stout setae and 2–4 small anteroventral setae (mostly 3 anterodorsal and 3 anteroventral) (Fig. 4T)................................................ D. peregrina

- Body entirely blackish brown, except yellow flagellomere 1, palpus and cercus (Fig. 1G); ventrobasal area of inner face of hind femur with row of four long stout setae (Fig. 6G); hind tibia with two anterodorsal stout setae, without anteroventral setae (Fig. 4H)....................................................................................... D. florescens

5. Ventrobasal area of inner face of male hind femur with ascending process (Fig. 6E, I)............................... 6

- Ventrobasal area of inner face of male hind femur without ascending process (Fig. 7B, D)............................ 7

6. Flagellomere 1 and palpus yellowish brown (Fig. 1K); inner face of hind trochanter with four long, sinuate setae arranged in longitudinal row on median area (Fig. 6I); ventrobasal area of inner face of hind femur with ascending process bearing two flattened, blunt setae (Fig. 6I); hind tibia with 2 or 3 short anteroventral setae (Fig. 4K)....................... D. hirsuta

- Flagellomere 1 and palpus dark brown (Fig. 1E); inner face of hind trochanter with two bifurcated stout setae on median area (Fig. 6E); ventrobasal area of inner face of hind femur with ascending process bearing two flagellate long setae (Fig. 6D, E); hind tibia without anteroventral setae (Fig. 4E).............................................. D. biflagella, sp. nov.

7. Dorsal face of fore and mid tarsomeres 5 dark brown (Fig. 2E); ventrobasal area of inner face of hind femur with three strong setae plus two long, narrow setae (Fig. 7D); hind tibia with single short anteroventral seta (Fig. 4Q); left plate of hypandrium without posterodorsal incision (Fig. 9C).................................................. D. nigritarsis, sp. nov.

- Dorsal face of fore and mid tarsomeres 5 pale brown (Fig. 2A); ventrobasal area of inner face of hind femur with 3 or 4 strong setae plus one short, fine seta (Fig. 7B); hind tibia with two short anteroventral setae (Fig. 4N); left plate of hypandrium with small, rounded posterodorsal incision (Fig. 9A).............................................. D. incisura, sp. nov.

A key to females of seven Diplonevra species from South Korea

(except D. biflagella sp. nov. with female unknown)

1. Hind tibia with three dorsal longitudinal setal palisades (Fig. 4C)............................................... 2

- Hind tibia with two dorsal longitudinal setal palisades (Fig. 4U)................................................ 3

2. Hind tibia with 3 or 4 anterodorsal stout setae (Fig. 4B); dorsal face of abdominal segment 5 blackish brown (Fig. 1D); venter of abdomen blackish brown (Fig. 1C)........................................................... D. abbreviata

- Hind tibia with one anterodorsal stout seta; dorsal face of abdominal segment 5 pale yellow; venter of abdomen pale yellow (based on Chinese specimens described and illustrated in Liu & Yang 2016: 33, fig. 33).................... D. bifasciata

3. Hind tibia with anterodorsal stout setae (Fig. 4H)............................................................ 4

- Hind tibia without anterodorsal stout setae (Fig. 4K)......................................................... 5

4. Body mostly yellowish brown with dark brown markings on abdominal tergites (Figs. 2L, 3B–E), or sometimes on scutum (Fig. 3D–E); wing vein M 1 almost straight, not distinctly curved (Fig. 5L); hind tibia with 2 or 3 anterodorsal stout setae and 2–4 small anteroventral setae (mostly 3 anterodorsal and 3 anteroventral) (Fig. 4T)............................ D. peregrina

- Body entirely blackish brown, except yellow flagellomere 1, palpus and terminalia (Fig. 1I, J); wing vein M 1 sinuated (Fig. 5E); hind tibia with two anterodorsal stout setae, without anteroventral setae (Fig. 4H)......................... D. florescens

5. Vein of costal sections II–III not thickened; abdominal tergite 2 with pair of round incisions anteriorly and single pointed incision anteromedially; abdominal tergite 4, 5 absent (based on original descriptions and illustrations in Michailovskaya, 2000: 3, figs. 15, 16)................................................................................... D. hirsuta

- Vein of costal sections II–III thickened (Fig. 5H); abdominal tergite 2 without distinct incisions on anterior margin; abdominal tergite 4, 5 well-developed (Fig. 2D)...................................................................... 6

6. First flagellomere, palpus and terminalia dark brown; wing vein Rs without weak depression apically; dorsal face of fore and mid tarsomeres 5 darkened (Fig. 2G); hind tibia with single short anteroventral seta (Fig. 4Q)........ D. nigritarsis, sp. nov.

- First flagellomere, palpus and terminalia yellowish brown; wing vein Rs with weak depression apically; dorsal face of fore and mid tarsomeres 5 not darkened (Fig. 2C); hind tibia with two short anteroventral setae (Fig. 4N)........ D. incisura, sp. nov.