Biology

Adults of this single-brooded moth fly during the day in June and early July (2). Populations occurring on moorland tend to fly later in the season (4), and show a preference for warm sunny weather (2). The caterpillars are present in July and August and live inside birch (Betula) or bog myrtle (Myrica gale) leaves, located at the tips of branches, which they spin together and feed on from inside. The pupal stage overwinters (2) either amongst moss or in spun leaves (4).