About Helotropha leucostigma Hübner, 1808
This section covers the technical description and variation of Helotropha leucostigma. Its wingspan measures 37–44 millimetres, which equals 1.5–1.7 inches. The forewings are dull dark brown with a faint reddish tinge; the veins are dusted with grey scales. The terminal area beyond the subterminal line is black-brown, except at the apex. The median area between the subcostal vein and vein 1 is somewhat darker than the rest of the wing. The inner and outer lines are indistinctly double: the inner line is outwardly oblique, and the outer line is bent on vein 5. The claviform stigma is barely visible. The orbicular stigma is oblique, elliptical, matches the ground colour of the wing, and has a paler annulus. The reniform stigma is white or dull yellow, and contains a double dark lunule with a pale centre; the outer edge of this dark inner lunule is sometimes absent, which makes the stigma appear more solidly yellowish or white. The space between the outer and subterminal lines is always slightly, and often visibly, paler than the ground colour of the wing. The hindwings are fuscous grey. In the aberration lunina Haw., the outer fascia is conspicuously paler, becoming pale brown or pinkish ochreous; the median vein and veins 3 and 4 at their base are white, and both stigmata are more strongly marked. Aberration albipuncta Tutt is a comparatively rare form, with nearly the whole of the reniform stigma being snow-white. fibrosa Hbn. describes a bright reddish fulvous form that may exist, but no one appears to have seen it. laevis Btlr., the Japanese form of the species, is as usual larger than the European form, and its outer line is rather more strongly excurved beyond the cell and incurved below.
