Idionyx travancorensis[2] is a species of dragonfly in the family Synthemistidae.

Laterally There is a narrow oblique stripe at the level of the spiracle and another on the hinder border of metepimeron.

In segment 2, the ventral border and a narrow apical stripe in yellow.

[4] The male can be easily distinguished by the shape of its inferior anal appendage and the female by its safironated wings and conical vesicle.

[4] Fraser (1931) states that the species occurs from 3,000 - 4,000 ft in the Western Ghats and breeds in mountain streams.