Butterfly - Eriogaster Catax

Eriogaster catax, the eastern eggar, is a species of moth in the family Lasiocampidae.

Eriogaster catax has a wingspan of 27–35 millimetres (1.1–1.4 in) in males, of 35–45 millimetres (1.4–1.8 in) in the females. This species shows a pronounced sexual dimorphism. The males are smaller and have feathery antennae. In males the basal part of the front wing is yellow-orange, while the outer part is pinkish-brown. In the females the front wings are browner. In both sexes, the front wings show a transversal line and a white discal spot within a dark border. Hind wings have no markings. Females are larger and at the end of the abdomen they have a tuft of dense gray-black hairs.

The eggs hatch in April. The larvae feed on Crataegus, Quercus, Betula, Populus, Prunus and Berberis species. This univoltine species fly at night in September and October.