Autographa gamma

Description

Autographa gamma is a migratory moth of the family Noctuidae which is named for the silvery Y-shaped mark on each of its forewings. The silver Y is a medium-sized moth with a wingspan of 30 to 45 mm. The wings are intricately patterned with various shades of brown and grey providing excellent camouflage. In the centre of each forewing there is a silver-coloured mark shaped like a letter Y or a Greek letter Gamma. There are several different forms with varying colours depending on the climate in which the larvae grow. P. gamma Forewing purplish grey, with darker suffusion in places; the lines pale silvery edged on both sides with dark fuscous, the outer line indented on vein 2 and submedian fold, as in circumflexa; the oblique orbicular and the reniform conversely oblique and constricted in middle, both edged with silvery: the median area below middle blackish, containing a silvery gamma; the subterminal dentate and indented, preceded by a darker shade; hindwing brownish grey with darker veins and a broad blackish terminal border: aberrations due to difference in ground colour are ab. pallida Tutt, in which the ground colour is whitish grey, with the markings appearing darker and more sharply defined; ab. rufescens Tutt where it is yellowish red, with the gamma mark pale golden, also the lines and edges of stigmata, and the whole underside reddish: and ab. nigricans Spul., in which the whole forewing up to the pale terminal space is violet black brown; in the ab. purpurissa ab. nov. (65a) the ground colour is deep olive brown; the inner and outer lines violet, the latter double; subterminal line lustrous violet, irregularly waved and below the middle forming a strong W-shaped mark; the gamma mark is pale golden, and the edges of the dark stigmata are, like the inner line, finely lustrous; a pale violet terminal stripe before termen; hindwing bronzy brownish, with broad dark terminal border.