Key to species (males) of Drabescus from China

Note. The following species are not included in the key: D. albostriatus, D. extensus and D. fuscorufous (only known from the female) and type specimens of D. atratus and D. notatus (unknown sex).

1 Head strongly triangularly produced, median length approximately three times as long as next to eyes; crown and frontoclypeus with the median bulging longitudinal ridges.............................................. D. mucronatus sp. nov.

- Head rounded or angularly produced, median length nearly as long as next to eyes or less than twice as long as next to eyes; crown and frontoclypeus regions without ridge.............................................................. 2

2 Anterior margin of head conspicuously produced angularly in lateral view; aedeagus with dorsoatrium present or absent, preatrium present or absent............................................................................. 3

- Anterior margin of head broadly rounded in lateral view; aedeagus without dorsoatrium, preatrium present... D. hainanensis

3 Aedeagal shaft without process in ventral view.............................................................. 4

- Aedeagal shaft with process in ventral view................................................................ 7

4 Style without subapical tooth-like process.................................................................. 5

- Style with small subapical tooth-like processes................................................. D. multipunctatus

5 Ventral margin of pygofer side without serrate process subapically.............................................. 6

- Ventral margin of pygofer side with serrate processes subapically..................................... D. cuspidatus

6 Aedeagal shaft dorsolaterad expanded subapically in lateral view..................................... D. henanensis

- Aedeagal shaft not expanded subapically in lateral view.............................................. D. ineffectus

7 Dorsal margin of aedeagal shaft without tooth in lateral view................................................... 8

- Dorsal margin of aedeagal shaft with middle fine teeth in lateral view................................. D. bilaminatus

8 Aedeagal shaft with a pair of processes.................................................................... 9

- Aedeagal shaft with two pairs of processes................................................... D. quadrispinosus

9 Aedeagal shaft with process bifurcate apically............................................................. 10

- Aedeagal shaft with process not bifurcate apically.......................................................... 14

10 Bifurcate branch of aedeagus without small process......................................................... 11

- Bifurcate branch of aedeagus with small process................................................... D. jinxiuensis

11 Aedeagal shaft subapically expanded in lateral view......................................................... 12

- Aedeagal shaft not expanded subapically in lateral view...................................................... 13

12 Valve triangular; subgenital plates with inner margin constricted........................................ D. furcatus

- Valve arciform; subgenital plates with inner margin relatively straight.................................. D. lamellatus

13 Aedeagal shaft relatively short, tapered to acute apex.................................................. D. gracilis

- Aedeagal shaft relatively long and cylindrical, apex rounded................................................ D. lii

14 Aedeagal shaft with process shorter than or subequal to length of shaft.......................................... 15

- Aedeagal shaft with process longer than length of shaft............................................ D. formosanus

15 Crown, pronotum and scutellum totally bright yellow................................................. D. pallidus

- Crown, pronotum and scutellum not as above.............................................................. 16

16 Head and thorax with yellowish medial longitudinal band.................................................... 17

- Head and thorax not as above........................................................................... 20

17 Connective with stem more than twice the length of arms.................................................... 18

- Connective with stem less than twice the length of arms...................................................... 19

18 Aedeagus without dorsoatrium................................................................. D. albosignus

- Aedeagus with dorsoatrium developed............................................................ D. piceatus

19 Dorsal margin of aedeagal process with irregular dentate processes in lateral view...................... D. multidentatus

- Dorsal margin of aedeagal process not as above..................................................... D. ogumae

20 Style without subapical tooth-like process................................................................. 21

- Style with subapical tooth-like processes......................................................... D. convolutus

21 Aedeagal shaft distally expanded in lateral view............................................................ 22

- Aedeagal shaft distally not expanded in lateral view......................................................... 25

22 Style with lateral lobe prominent........................................................................ 23

- Style without lateral lobe...................................................................... D. minipenis

23 Aedeagal shaft with process extending nearly to apex of shaft in lateral view..................................... 24

- Aedeagal shaft with process extending nearly to half of shaft in lateral view........................... D. shillongensis

24 Connective Y-shaped, stem longer than arms.............................................. D. macrocladus sp. nov.

- Connective U-shaped, stem shorter than arms..................................................... D. pellucidus

25 Aedeagal shaft relatively straight in lateral view............................................................ 26

- Aedeagal shaft curved dorsad in lateral view............................................................... 28

26 Style with apical process wide, rather thick and relatively short................................................ 27

- Style with apical process narrow and very long.................................................. D. albofasciatus

27 Anteclypeus and frontoclypeus black................................................................ D. piceus

- Anteclypeus and frontoclypeus yellowish brown.................................................... D. testaceus

28 Aedeagal shaft with process extending nearly to apex of shaft................................................. 29

- Aedeagal shaft with process extending nearly to mid-length of shaft............................................ 30

29 Style with lateral lobe prominent; connective U-shaped........................................ D. nervosopunctatus

- Style without lateral lobe; connective Y-shaped...................................................... D. vilbastei

30 Connective with stem slender, longer than arms.................................................. D. limbaticeps

- Connective with stem robust, nearly as long as arms................................................... D. nitobei