Eurema hecabe, the common grass yellow,[1][2] is a small pierid butterfly species found in Asia, Africa and Australia.

[5] The region of dorsal surface that appears visibly yellow to humans also reflects brightly in the ultraviolet (320-400 nm) owing to the presence of multilayer cuticular nanostructures.

[5] Upperside: ground colour and markings much as in wet-season specimens, the emargination on the inner side of the black area and the tornal dilatation on the forewing similar.

In addition, on the forewing there is a preapical, very prominent, transverse, elongate spot or short bar or reddish brown extended downwards from the costa.

[5][8] Eggs are laid on Abrus precatorius, Falcataria moluccana, Acacia sp., Aeschynomene species and numerous other Leguminosae, Euphorbiaceae and Cucurbitaceae sp..[9] Studies suggest that the females can discriminate colours when choosing host plants for oviposition.

"[5] Pupa: "Suspended by the tail and by a moderately long band; the abdominal segments are round, but the thorax is much compressed, the wing-cases uniting to form a deep sharp keel.

Having selected a dead branch of some neighbouring bush, they acquired the colour of their surroundings as nearly all Pierine and Papilionine pupae do to a greater or less extent.