Rhagastis acuta 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 Sphingidae

Sphingidae

Sphingidae is a family of moths , commonly known as hawk moths, sphinx moths and hornworms, that includes about 1,200 species . It is best represented in the tropics but there are species in every region . They are moderate to large in size and are distinguished among moths for their rapid,...

 family. It is known from south-east Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, including 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...

, Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

 and Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

.

It is similar to Rhagastis velata

Rhagastis velata

Rhagastis velata is a moth of the Sphingidae family. It is known from Nepal, north-eastern India, Thailand, central and southern China and Taiwan....

and Rhagastis hayesi

Rhagastis hayesi

Rhagastis hayesi is a moth of the Sphingidae family. It is known from south-east Asia, including Burma, Vietnam and Thailand.It is similar to Rhagastis acuta but can be distinguished by the lateral pattern of the abdomen, the forewing upperside ground colour which is always darker olive-brown and...

. The upperside of the abdomen has a pair of vestigial or well-developed lateral golden stripes. The forewing upperside is similar to Rhagastis castor aurifera

Rhagastis castor

Rhagastis castor is a moth of the Sphingidae family. It is known from Nepal, north-eastern India, Thailand, southern China and Vietnam, Sumatra, Java and Taiwan....

. It has an olive-green tone. The forewing underside has postmedian dots and a submarginal band which is not joined to the basal area. The hindwing underside is without a small black discal spot.