I’ve never seen a Buff-tip moth (Phalera bucephala) except in photographs (they look incredibly like twigs – see images on the Butterfly Conservation website here). But yesterday I found their larvae, lots of them, all huddled together on the top side and underside of an Oak leaf.
The adult moth, which flies from May to early August, lays clusters of eggs under the leaves of the trees their caterpillars feed on, which, as well as Oak, include Hazel and the various birches and sallows, amongst others.
The larvae hatch out after 2-3 weeks and start eating. It takes just a month for them to go through their four instars, after which they move down into the ground to pupate. Come the spring, the whole process begins again.