| Dark grass-brown | |
|---|---|
| Orsotriaena medus mandata from Kerala, India | |
| Orsotriaena medus medus from Mindanao, Philippines | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Lepidoptera |
| Family: | Nymphalidae |
| Genus: |
Orsotriaena Wallengren, 1858 |
| Species: | O. medus |
| Binomial name | |
|
Orsotriaena medus (Fabricius, 1775) |
|
Orsotriaena medus, the dark grass-brown, is a butterfly found in South Asia, Southeast Asia, and Australia. The butterfly has historically been called the "nigger", but it has been renamed in Australian faunal works to the socially acceptable name of smooth-eyed bushbrown.
Orsotriaena medus is a medium-sized butterfly with wingspan of 45 to 55 mm (1.8 to 2.2 in). The butterfly is dark brown above with a thin marginal pale border. The upper hindwing having a thin submarginal line. There are no eyespots on the upperside of the wings.
Below, the butterfly has a white discal band which runs across both wings. It has five eyespots on the underside of the wings. In the forewing, it has two eyespots, with the anterior eyespot slightly smaller. In the hindwing, it has two eyespots on the apical region and a separate ocellus in the tornal (hindmost) region. The uppermost of the eyespots in the hindwing are greatly smaller, while the remaining two are more or less of equal sizes.
The eggs are spherical and yellowish. They are laid on the leaf blades and stems of grasses. The larvae are spindle shaped, transversely wrinkled, and covered in small tubercles, giving it a rough appearance. Two long brown spines on the head point forward, while a pair of pinkish prongs project from the anal segment. The colour above is rosy red with a blue dorsal and a white lateral line, below which, the underparts are green.
The pupae are perpendicularly suspended, slender and regular, except that the head-case is produced into a long beak formed of two thin processes like split straws. The colour is whitish brown to yellow, with faint bands of a darker shades. It resembles a large grain of barley or a tiny banana.
Orsotriaena medus superficially resemble members of the genus Mycalesis (bushbrowns), but can readily be identified by the number of spots.
Orsotriaena medus medus (left) and Orsotriaena medus mandata (right)
Upperside, seen in Kodagu district
Orsotriaena medus cinerea, Indonesia
1905 illustration of Orsotriaena medus
Orsotriaena medus moira, the upper surfaces of the wings of the species are unmarked and plain brown
Mating pair