The Small Grass Yellow (Eurema smilax) is a small pierid

Pieridae

The Pieridae are a large family of butterflies with about 76 genera containing approximately 1,100 species, mostly from tropical Africa and Asia. Most pierid butterflies are white, yellow or orange in coloration, often with black spots...

 butterfly

Butterfly

A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

 species found in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, including Lord Howe Island

Lord Howe Island

Lord Howe Island is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, directly east of mainland Port Macquarie, and about from Norfolk Island. The island is about 11 km long and between 2.8 km and 0.6 km wide with an area of...

. It is also present on Java

Java

Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...

.

The wingspan

Wingspan

The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...

 is about 30 mm. The upper surfaces of the wings are yellow with a black band around the edge, and a black dot near the middle. The undersides are yellow with variable brown markings.
The species goes through seasonal forms of wet-season and dry-season forms.

The larvae have been recorded feeding on Cassia fistula, Neptunia monosperma, Neptunia gracilis, Senna acclinis, Senna coriacea, Senna coronilloides, Cassia nemophila, Senna artemisioides petiolaris

Senna artemisioides

Senna artemisioides is a flowering plant in the family Fabaceae. It is commonly known as Silver Cassia or Feathery Cassia - although "cassia" generally refers to the largest-growing Cassiinae. Some of its distinct subspecies also have common names of their own...

and Senna guadichaudii.