Local in broad-leaved woodland, marshes, river-banks, gravel pits, gardens and parks throughout England, Wales and southern Scotland; widespread but only locally common across most of Hampshire and the Isle of Wight. Wingspan 28-34 mm. The main confusion species is Double Kidney I. retusa
, but I. subtusa
has distinctly convex subterminal fascia (straight in I. retusa
) and much less pointed apex than I. retusa
. Larva feeds high up in Aspen, Black Poplar and White Poplar trees, over-wintering as an egg.