Key to species of Gergithus

1. Frons with stripes or spots............................................................................... 2

-. Frons without stripes or spots........................................................................... 37

2. Frons without transverse bands........................................................................... 3

-. Frons with transverse bands............................................................................ 22

3. Frons with two spots................................................................................... 4

-. Frons with longitudinal stripes........................................................................... 6

4. Frons with two spots near vertex.......................................................................... 5

-. Frons with two spots near frontoclypeal suture; tegmina shiny brown, translucent. Burma ............. G. ignotus Melichar

5. Clypeus with two longitudinal stripes; tegmina dirty yellow, costal margin brown, at apical third with a pale yellow mark, veins pale green. China (Taiwan)..................................................... G. pendulu s Chan & Yang

-. Clypeus without such stripes; tegmina dark reddish brown, margin reddish brown. China (Taiwan), Japan (Honshu, Shikoku and Kyushu)...................................................................... G. carbonarius Melichar

6. Frons with a central red longitudinal fascia................................................................. 7

-. Frons with two longitudinal fasciae...................................................................... 15

7. Frons with a very broad central fascia..................................................................... 8

-. Frons with moderately broad central fascia................................................................ 10

8. Tegmina without fasciae................................................................................ 9

-. Tegmina black with a sublateral fascia terminating at a little before apex on inner margin, a broader central transverse fascia, from which there posteriorly bifurcates a short oblique fascia to suture; frons somewhat narrow; clypeus with two red fasciae. India (Madras)...................................................................... G. nilgiriensis (Distant)

9. Clypeus yellow; tegmina brownish-yellow to pitch-brown. India (Madras)........................ G. vi d ul us (Melichar)

-. Clypeus centrally pale virescent, with narrow submarginal fascia; tegmina thickly finely pilose. India (Madras, southern area)....................................................................................... G. erebus Distant

10. Tegmina with fasciae, spots or irregular marks.............................................................. 11

-. Tegmina without such marks, venation reticulate........................................................... 13

11. Clypeus green with submarginal sanguineous lines; tegmina with the disc suffused with black, apical area paler, extreme mar- gin and a submarginal narrow line black. India (southern area, Madras)............................. G. proteus Distant

-. Clypeus without such lines............................................................................. 12

12. Generally sordidly flavescent; frons dirty green; tegmina dirty green or brownish-yellow to brown with anterior costal margin black, a small black spots and two submedian subcurved oblique flavous lines. Sri Lanka ................ G. schaumi Stål

-. Generally very pale flavescent; tegmina with about posterior third tawny-grey inwardly margined with umber-brown, with an oblique piceous fascia. India (Madras).................................................... G. elongates (Distant)

13. Clypeus with longitudinal fasciae........................................................................ 14

-. Clypeus black; frons green; tegmina dirty green, translucent, oblong. Australia (Key Island)........... G. pigrans Melichar

14. Clypeus with two longitudinal fasciae testaceous; frons with lateral margins testaceous; tegmina pale ochraceous with the venation very dense and somewhat closely reticulate. India (Madras)............................ G. reticulates (Distant)

-. Clypeus with one longitudinal fasciae red; frons and clypeus black with lateral margins broadly yellowish white; tegmina black with network of veins at base and yellowish apex. Malaysia (Sarawak, Malacca, Malaya), Indonesia (Java, Nias Island, Suma- tra), Borneo, Thailand ..................................................................... G. n i ger (Walker)

15. Tegmina with fasciae spots............................................................................. 16

-. Tegmina subhyaline, without marks, venation somewhat reticulate. China (Taiwan)............. G. horishanus Matsumura

16. Frons with two black longitudinal fasciae.................................................................. 17

-. Frons with two red or castaneous longitudinal fasciae........................................................ 18

17. Frons with two parallel black lines, and separated by a yellowish stripe; tegmina green, finely punctured, base of costa with two parallel rufous-brown lines, and a very narrow yellowish edging continued round the rest of the tegmina. Sri Lanka ....................................................................................... G. herbaceus (Distant)

-. Frons with lateral margins flavescent, sublateral margins black, central fascia red, its disc finely transversely striate; tegmina with the veins reticulate, prominent distinctly, a broad curved piceous fascia connect with posterior margin by a short and straight fascia at middle. Burma (Tenasserim)................................................ G. v eno sus (Distant)

18. Mesonotum with longitudinal fascia...................................................................... 19

-. Mesonotum without any fascia.......................................................................... 21

19. Mesonotum opaline green with the anterior margin and central fascia testaceous................................... 20

-. Mesonotum with a central fascia and a small spot on each side; Tegmina much shaded and spotted with castaneous between the veins, but with a prominent pale spot on each tegmen near middle of inner margin and paler also on apical area. Sri Lanka ................................................................................... G. complicates Distant

20. Tegmina thickly finely punctuate, with black costal markings consisting of two basal streaks, followed by three spots, apical margin narrowly black. Sri Lanka ......................................................... G. versicolor Distant