Phostria obscurata is a moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

 of the Crambidae

Crambidae

The Crambidae are the grass moth family of Lepidoptera . They are quite variable in appearance, the nominal subfamily Crambinae taking up closely folded postures on grass-stems where they are inconspicuous, while other subfamilies include brightly coloured and patterned insects which rest in...

 family. It is found in Taiwan

Taiwan

Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...

, India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, Sri Lanka

Sri Lanka

Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

, Singapore

Singapore

Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

 and Burma.

Adults are purplish-brown. The forewings have an extremely indistinct blackish transverse outwardly-curved narrow antemedial band, and an irregular postmedial band. There is a spot in the middle of the cell, and a streak at the end. The hindwings have a similar irregular discal band.