Macroglossum buini 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 Bougainville Island

Bougainville Island

Bougainville Island is the main island of the Autonomous Region of Bougainville of Papua New Guinea. This region is also known as Bougainville Province or the North Solomons. The population of the province is 175,160 , which includes the adjacent island of Buka and assorted outlying islands...

.

The length of the forewings is about 20 mm. It is a member of the uniformly dark Macroglossum

Macroglossum

Macroglossum is a genus of moths in the Sphingidae family. It has over 110 described species.-Species:*Macroglossum adustum - Rothschild & Jordan 1916*Macroglossum aesalon - Mabille 1879*Macroglossum affictitia - Butler 1875...

species group, but is smaller and shorter-winged than the other species in this group. The upperside of the hindwing, thorax and abdomen are largely black. The forewing upperside and underside, as well as the hindwing underside are largely dark brown. The forewing underside has an irregular bright yellow basal area extending about 3 mm from the base.