On Sep 27, 2007, philomel from Castelnau RB Pyrenées France (Zone 8a) wrote:
This moth flies May - July, the males both night and day, the females only at night. The caterpillars feed on bramble and other low shrubby vegetation. When the caterpillars are fully grown they hibernate and then pupate in the spring.
I found three while gardening. They were ready for hibernation and hidden in some strawberry plants next to Santolina.