Fustius sterlingi 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 Micronoctuidae

Micronoctuidae

The Micronoctuidae are a family of moths that includes about 400 described species. The family was first described in 2005.Micronoctua karsholti is the smallest of all species in the Noctuoidea superfamily.-Taxonomic History:...

 family. It is known from Hong Kong

Hong Kong

Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

.

Its 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 7.5-9.5 mm. The head, patagia, anterior part of tegulae, prothorax, basal part of the costa and costal upper patch of the medial area are black. The forewing ground colour in males is light grey, except a black in medial area. In females it is black brown and especially dark in the medial area. The crosslines are all present, although the subterminal line is weak. The terminal line is marked by black interneural dots. The hindwing is light grey in males and grey in females, with an indistinct discal spot. The underside of the forewing is grey. The underside of the hindwing is light grey, with an indistinct discal spot.