About Rhizedra lutosa Hübner, 1803
Rhizedra lutosa Hübner, 1803 has a wingspan of 42–50 mm, and forewings measure 16–23 mm in length. Forewings are dull white, finely dusted with blackish color in the intervals, and sometimes have a slight rufous tinge. The outer line appears as a row of blackish dots, which is often obsolete. Hindwings are whitish and tinged with grey; they sometimes have an outer series of dark spots. The aberration crassicornis Haw. has intensified black dusting on both wings, which in some cases forms dark horizontal streaks on the forewing, and the rows of spots on both wings are strongly marked. Aberration rufescens Tutt is the red form corresponding to the typical lutosa Hbn., and may either have or lack the rows of spots. Tutt named the more heavily dusted red form, which corresponds to ab. crassicornis Haw., as rufescens-suffusa. The population found in Japan is classified as a separate subspecies, griseata Warren. In males of this subspecies (females have not been examined), hindwings are dark grey beyond the middle with a pale fringe, while forewings are greyer ochreous, with pale veins more distinctly outlined by dark scaling. Two male specimens, collected from Ichikishiri, Yezo in August 1890 by Dr. Fritze, are held in the Tring Museum.
