Theretra improvisa 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 Bioko

Bioko

Bioko is an island 32 km off the west coast of Africa, specifically Cameroon, in the Gulf of Guinea. It is the northernmost part of Equatorial Guinea with a population of 124,000 and an area of . It is volcanic with its highest peak the Pico Basile at .-Geography:Bioko has a total area of...

.

The wingspan

Wingspan

The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...

is about 50 mm. The forewings are very broad and the outer margin is strongly convex. The apex is sharply pointed and the inner margin strongly concave before the tornus. The upperside of the head and thorax is dark black-brown, but the thorax has a pale grey double line along each edge. The forewing upperside has a pale band running between the third and fourth postmedian lines and a pale band between the fourth and fifth postmedian lines which is strongly developed.