The Reddish Light Arches (Apamea sublustris) is a moth of the Noctuidae family. It is found in central and southern Europe (including southern Great Britain), Turkey and the Caucasus. The wingspan is 42–48 mm.Differs from the very similar Apamea lithoxylaea in having the forewing shorter, more strongly suffused with brown, or brownish grey, especially along costa which in lithoxylaea is whitish: stigmata much plainer; outer line more continuously lunulatedentate, the median shade at its lower extremity extending from inner to outer line; the terminal brown shades more distinct; the brown clouding on submedian fold before submarginal line absent; hindwing withbetter-defined markings.