Nephele joiceyi 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 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...

 (including Sumatra).

The length of the forewings is 44 mm. It is very similar to Nephele hespera

Nephele hespera

Nephele hespera is a sphingid moth found in the tropical and subtropical forests of Sri Lanka, India, Nepal, Burma Myanmar, southern China, Thailand, Vietnam, Malaysia and Indonesia....

but much larger. The abdomen upperside has lateral black patches. The forewing underside has postmedian and submarginal lines converging. The hindwing upperside is darker than in Nepnele hespera.