Biology

Adults fly after dusk (usually very late in the night) between late May and early July (4). Caterpillars occur from July to April (2), feeding on wilted oak leaves (4). The caterpillars usually overwinter when almost fully grown (2). Snapping one metre long oak branches at head height in late May / early June and leaving them hanging on the tree to wilt creates ideal habitat to search for the caterpillars in August and September (4).