The adult insect (imago) over-winters in dry dark places, such as hollow trees or out buildings. In late February or early March the butterflies emerge and mate. The females lay their pale green eggs (ova) in a continuous band around the upper twigs of Elm (Ulmus spp.), Sallow (Salix caprea and Salix viminalis), Pear (Pyrus spp.), and Prunus spp. trees. The caterpillars (larvae) are gregarious, and systematically strip the topmost twigs of the tree bare. There is only one generation per year, and the imagos emerging in mid summer seek out sources high in sugar to feed. Tree sap and damaged ripe fruits are particularly suitable sources.
It is found in Europe, northern Africa, and western Asia. It is an extreme rarity in Britain, although it used to be widespread throughout England and Wales.