Key to the species of Idiocysta

The key below is based on a comparison of the type material of the new species with the illustrations (United States National Museum of Natural History 2019) and the original descriptions (China 1930; Drake & Poor 1943; Guilbert 1999, 2001) of other congeners.

1 Head with spines...................................................................................... 2

- Head without spines................................................................................... 4

2 General color yellowish white; rostrum reaching posterior margin of metasternum; paranotum with 4 rows of areolae at widest part; costal area of hemelytron with 3 rows of areolae at widest part.................................. takarai sp. nov.

- General color beige or black; rostrum not reaching posterior margin of metasternum; paranotum with 5–6 rows of areolae at widest part; costal area of hemelytron with a single row of areolae throughout its length............................. 3

3 General color black; paranotum with 5 rows of areolae at widest part; outer margins of paranota touching each other throughout their length.................................................................... I. fijiana Drake & Poor, 1943

- General color beige; paranotum with 6 rows of areolae at widest part; outer margins of paranota not touching each other throughout their length............................................................. I. vanuana Guilbert, 2001

4 Rostrum reaching middle of metasternum; outer margins of paranota touching each other throughout their length...................................................................................... I. bicolor Drake & Poor, 1943

- Rostrum not reaching middle of metasternum; outer margins of paranota not touching each other throughout their length... 5

5 Costal area of hemelytron with a single row of areolae throughout its length....................................... 6

- Costal area of hemelytron with a single row of areolae in basal part and in 2 rows in remaining parts................... 7

6 Rostrum reaching middle part of mesosternum....................................... I. vanuatuensis Guilbert, 1999

- Rostrum reaching posterior margin of mesosternum................................... I. dryadis Drake & Poor, 1943

7 Rostrum reaching posterior margin of mesosternum..................................... I. floris Drake & Poor, 1943

- Rostrum reaching middle part of mesosternum............................................. I. hackeri China, 1930