The foodplant is mistletoe. I've previously only found it in larger apple orchards where this grows in abundance. However this came from one of twenty clumps in a lone willow. It's about 2 miles from another site but this still expands the sort of habitat that could be worth searching. There are lots of limes and poplars in the area that could easily host populations of the moth.
The overwintering site is marked by a small circular entrance hole. The larva lives in a crescent shaped mine. This is expanded into a blotch in the spring though milder weather may prompt some feeding before then.