Key to species of Eucriotettix from Singapore

1. Hind femur stouter, 3.2 times as long as wide. External lateral carina of pronotum distinctly raised and infrascapular area broadened (Fig. 7 А). Lower side of the lateral lobes of pronotum deeply excised behind triangularly pointed projection (Fig. 7 B).............................................................................. E. ridleyi Günther, 1938

- Hind femur slender, 3.4–3.8 times as long as wide. External lateral carina of pronotum almost straight and infrascapular area narrow (Figs 5 C, 5D, 6C, 6D). Lower side of the lateral lobes of pronotum behind triangular projection weakly excised (Figs 5 B, 6B) or almost straight (Figs 5 A, 6A)...................................................................2

2. Frontal ridge narrow; antennal socket situated distinctly above the lower margin of eyes (Fig. 8 B). Fore femur 3.8–4.1 times as long as wide; hind femur 3.4–3.5 times as long as wide. Lower side of the lateral lobes of pronotum behind triangularly pointed projection almost straight (Fig. 8 A). Male subgenital plate in lateral view shallow excised near apex (Fig. 8 D). Posterior margin of female subgenital plate broadly rounded with indistinct median projection (Fig. 8 G)........... E. guentheri sp. nov.

- Frontal ridge broadened; antennal socket situated between the lower margin of eyes (Fig. 8 I). Fore femur 4.2 times as long as wide; hind femur 3.6–3.8 times as long as wide. Lower side of the lateral lobes of pronotum behind projection excised (Fig. 8 H). Male subgenital plate in lateral view deeply excised near apex (Fig. 8 K). Posterior margin of female subgenital plate straight with distinct medial projection (Fig. 8 N)............................................ E. simulans sp. nov.