About Nyctobrya muralis (Forster, 1771)
Nyctobrya muralis (Forster, 1771) has a wingspan of 27 to 34 millimeters, and its forewings measure 12 to 15 millimeters in length. The forewing is smooth, and solid unspeckled green, with prominent black markings. The club-shaped claviform stigmata and round orbicular stigmata merge together to form a single blotch. The named aberration ab. par Hbn. is grey-green with darker green dusting, and its black markings are not visible. The aberration ab. impar Warr. is green dusted with black or rufous; its lines are more or less indistinct, and its green color fades faster than the green color of the typical N. muralis. This form occurs only at Cambridge, where the typical type form does not exist. Four additional aberrations of this species have been formally differentiated. Ab. viridis Tutt is a rich green, with no black or grey dusting. Ab. flavescens Tutt matches the typical form in pattern, but its green color is changed to yellow; this color change appears even in bred specimens. Ab. pallida Tutt has the typical species markings on a whitish-grey ground color. Ab. obscura Tutt is a dull brownish grey, with obscured markings and no trace of green at all. All four of these last aberrations are found on the coast of Kent and at Queenstown in Ireland.
