About Tiliacea citrago Linnaeus, 1758
Technical description and variation: The wingspan of Tiliacea citrago is 28–33 mm. The forewing is yellow, thickly freckled with orange; the veins are finely ferruginous. The lines are ferruginous brown, with the median line being thick. All lines run more or less parallel to each other and to the termen. The inner line runs obliquely outwards from the costa to the subcostal vein, and again from vein 1 to the inner margin, where it touches the median. The stigmata match the ground color of the wing, and have brown rings; the orbicular stigma is large and round; both stigmata have brown centres. The submarginal line is formed of disconnected pale lunules edged inwardly with darker color. The hindwing is pale yellow.
aurantiago Tutt is a darker form, with deeper orange color, and is sometimes darkened by grey dusting. This form occurs in Britain.
ab. incolorata ab. nov. [Warren], also known as incolorata, is a rare form that equally deserves a distinctive name. In this form, the ground color is pure pale ochreous, without any orange freckling. The veins and lines are faintly brownish, and the stigmata are almost obsolete. The fringe is pale, and the hindwing is white. Only one example of this form has been seen, a female that is certainly British, but with no exact recorded locality.
The form subflava Ev. originates from Denmark, the Baltic region, St. Petersburg, and the Ural Mountains; it has also been recorded from Asia Minor. This form has a quite different appearance. The three lines – inner, outer, and submarginal – are accompanied by brown bands of uniform width. The stigmata are marked with brown, and the hindwing has brown veins and a brown terminal border.
