Key to species of Cosmolaelaps occurring in Republic of Korea

1. Dorsal setae spatulate with or without a small basal protuberance............................................... 2

- Dorsal setae awl-shaped, knife or scimitar-like.............................................................. 6

2. Dorsal setae without a small basal protuberance............................................................. 3

- Dorsal setae with a small basal protuberance................................................................ 4

3. Swollen humps on tibia I and basitarsus II–IV, surface of genital shield covered with fine granules....... C. oedipus sp. nov.

- Without any hump-like structures on legs, surface of genital shield covered with lineate reticulation................................................................................................... C. sansungensis sp. nov.

4. 41 pairs of dorsal setae spatulate sickle-shaped........................................ C. robustochaetes Ma & Lin

- 40 pairs of dorsal setae spatulate with round, serrated margin................................................... 5

5. Dorsal shield with six accessory setae, sternal setae st1 on the shield.......................... C. hallasanensis sp. nov.

- Dorsal shield with 10 accessory setae, sternal setae st1 off the sternal shield.................... C. cavosternalis sp. nov.

6. Dorsal setae short and slender, awl-shaped.................................................. C. hrdyi (Samšiňák)

- Dorsal setae relatively expanded, knife or scimitar-like, with conspicuous basal protuberance......................... 7

7. Dorsal setae knife-like, not elongate, at most reaching base of following setae, femora II and IV with spatulate setae............................................................................................. C. vacua (Michael)

- Dorsal setae scimitar-like, long, almost all setae reaching well past base of following setae, femora II and IV without spatulate setae............................................................................................... 8

8. Dorsal setae Z5 shorter than J5 (ratio of J5 / Z5 ≈ 1.5)........................................... C. chianensis (Gu)

- Dorsal setae Z5 longer than J5 ........................................................................... 9

9. Post-anal seta thickened, sparsely barbed and apically hooked, inserted on a small tubercle, Jv5 on opisthogastric cuticle well thickened and apically hooked................................................. C. sejongi Keum, Jung & Joharchi

- Post-anal seta and Jv5 on opisthogastric cuticle simple, slightly thickened....................................... 10

10. Genital shield notably expanded behind the st5, epistome with apical projection medially.......... C. brevipedestra (Karg)

- Genital shield not notably expanded, epistome with round serrated margin...................... C. hortensis (Ishikawa)