Feeding on an ash. Only the second time I have seen this species, the last time 5 years ago. I have looked and looked but until this one, no success. The moths are pretty common at mothing lights, so no idea why the larvae are so hard to find. Who'd ever guess these are moth caterpillars? To see the colourful moth they become: https://pbase.com/laroseforest/image/170810403