Varies in colour from yellowish buff to creamy white, the colour on the margins always deeper; the rows of black spots on the fore wings are usually well defined, but sometimes those of the two central series are very faint, or quite absent, whilst an unusual number appear in the outer marginal series, Occasionally black scales appear on the veins, connecting the spots, and forming the figures
more or less distinctly; such forms are known as var. signata, Borkh. The moth appears in June and July. (Plate [95], Figs. 7, 9.)
When resting, the moth hangs from a blade of grass, or leaf of some plant; it then has a very transparent appearance. Barrett suggests that this gave rise to the English name it now bears, and by which it was known to Haworth and entomologists of his time.
Buckler and Hellins describe the caterpillar as blackish-brown above, and dark-reddish grey or purplish grey on the sides; a series of yellow spots along the middle of the back, then a white
