Ábrahám Levente – Farkas Sándor: Butterflies along the river Drava, 2008

Although there is considerable similarity between the appearance of the comma butterfly (Polygoniac-album) [23] and nettle-tree butterfly (IJbytheü celtis) [24 ], yet they belong to different families. The nettle-tree butterfly has tubular, elongated labial palpi. It is a migrating species. Both species have two generations within a year, and appear among the first butterflies in early spring. Their second generation flies in the summer period.