Hippotion commatum 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 Papua New Guinea

Papua New Guinea

Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...

.

The length of the forewings is 37-38 mm. The abdomen upperside is similar to Hippotion velox

Hippotion velox

Hippotion velox is a species of Sphingid moth or the family Sphingidae. It is found throughout the Indo-Australian tropics east to Fiji and New Caledonia, north to Hong Kong, Taiwan and southern Japan.The wingspan is 54-76 mm....

, but the paired oblique subdorsal silvery dashes are replaced by elongate greyish-white spots that are parallel to the dorsal line. The forewing upperside is also similar to Hippotion velox.