Key to the South Korean species of Neurotoma

1. Head covered with long hairs; occipital carina blunt or inconspicuous............................................ 2

- Head glabrous or nearly so except for sparsely pilose gena and clypeus; occipital carina sharply defined................. 3

2. Abdomen without distinct bluish luster. Female: Clypeus with large creamy white mark medially; pronotum entirely black laterally. Male: Head entirely black...................................................... N. atrata Takeuchi, 1930

- Abdomen with distinct bluish luster dorsally. Female: Clypeus with two large lateral creamy white marks; pronotum in lateral view usually marked with yellowish white. Male: Head with large subtriangular mark on clypeus..................................................................................................... N. coreana Shinohara, 1980

3. Antenna with scape and pedicel usually entirely yellow in both sexes, at most with obscure blackish mark on upper side of scape.......................................................................... N. iridescens (André, 1882)

- Antenna with scape and pedicel mostly black in female, at least scape black dorsally in male.......................... 4

4. Head, thorax and abdomen richly marked with whitish yellow; facial and frontoclypeal crests prominent, sharply carinate..................................................................................... N. satoi Shinohara, 1980

- Head, thorax and abdomen with few pale-yellow marks; facial and frontoclypeal crests low, not sharply carinate.......... 5

5. Small species, female 7–9.5 mm, male 7.5–8.5 mm. Head entirely black, except for sometimes obscure small spot at upper facial orbit; vertex and temple smooth, usually without distinct punctures; mesoscutellum and metascutellum entirely black in female; cell C of forewing pilose all over........................................... N. sibirica Gussakovskij, 1935

- Large species, female 13 mm, male 12 mm. Head with large pale yellow mark between antennae in female (Fig. 3), anterior surface mostly pale yellow in male (Fig. 9); vertex and temple covered with dense, well-separated punctures (Figs 3, 9); mesoscutellum and metascutellum pale yellow in female (Fig. 1); cell C of forewing glabrous, with some pilosity in apical posterior part (Figs 14, 15)..................................................................... N. silla sp. nov.