The common grass yellow, is a small pierid butterfly species found in Asia, Africa and Australia. Common grass yellow (Eurema hecabe) is a beautiful yellow butterfly. They have a wingspan of 35 to 45 mm. Common Grass Yellow butterflies are small in size. They have bright yellow wings, with blackish brown bordering on the upper side and the underside of the wings are paler yellow with brown speckles. They have a narrow black band on the hind wing. They have different coloration in their wings depending on the season. Males have a brand lying along the cubital vein on the forewing underside. The female is larger and a paler yellow, with broader black but diffused markings on the upper sides of both wings. There are typically two cell spots on the forewing – a characteristic that is mainly used to identify the lookalike species in the genus. Males congregate to imbibe mineralized moisture from damp sandbanks, often in scores. Females are more discreet in behavior, normally being seen singly when nectaring.
Eurema hecabe prefer open forest areas, wastelands and grasslands. They also found along roadsides, and in parks and gardens at elevations between sea level and about 1000 metres. They are found flying close to the ground in open grass and scrub. Their habit of gathering in small groups on patches of damp sand or soil. Male butterflies are often seen in large groups, and the females usually fly about by themselves to find nectar from a wide variety of plants. They like to fly quickly, close to the ground, are found in open grassy or bushy terrain, hence their name.
Eurema hecabe regularly visit flowers for nectar and puddle on wet grounds for minerals.
Butterflies reproduce the way other animals do sperm from a male fertilizes eggs from a female. Males and females of the same species recognize one another by the size, color, shape and vein structure of the wings, all of which are species specific. Butterflies also recognize each other through pheromones, or scents. During mating, males use clasping organs on their abdomens to grasp females. The eggs of the Common Grass Yellow are laid singly on a leaf/leaflet of the host plant and whitish in color and has quite a few shallow vertical ridges and indistinct horizontal striations.Eggs are always spindle-shaped, and changing to a darker shade before hatching. In the larvae stage the color of body is dull green with a white line edged with yellow, and the color of head is green. The larvae of this species feed on a variety of plants and grasses, depending on the region, although they often include plants from Euphorbiaceae, the family of spurges, and Fabaceae, the family of legumes, peas and beans. In the pupa stage the length of body is between 16 to 22 mm. The pupa has a pointed head and a keeled wing pad, and its body is mostly unmarked except for a faint pale brownish and narrow dorsal band. Ordinarily the pupa is solitary and green, but sometimes on a twig in large numbers. Butterflies also recognize each other through pheromones, or scents. During mating, males use clasping organs on their abdomens to grasp females.