Oreta unilinea is a moth in the family Drepanidae. It was described by William Warren in 1899. It is found in New Guinea,[1] where it is known from Papua and Roon Island.[2]
The wingspan is about 48 mm. The forewings are dull fulvous with a lilac tinge. The lower arm of the discocellular is marked with white scales. There is a deeper fulvous diffuse shade from the costa just before the middle, transversing the discocellular, and very obscurely curved towards the base of the inner margin. There is a deeper fulvous slightly flexuous line, edged externally with pale yellowish from just beyond the middle of the inner margin into the apex. The hindwings have a paler costal area and deeper fulvous central and marginal shades. The submarginal area has a few black scales and traces of two curved rows of darker spots between the veins. The discocellular is marked as in the forewings.[3]