Common in parks and urban areas throughout much of south-eastern England. An adventive species, first recorded in Europe in Macedonia in 1995, from where it has spread rapidly. In Britain, first recorded in Wimbledon, London in 2002, reaching plague proportions around Greater London and along the Thames Valley by 2006. The first record in Hampshire occurred in 2004, and it appears that it is being dispersed along railway lines and major roads, and now widespread and abundant across much of the county and on the Isle of Wight. Wingspan 8 mm. The larva mines the leaves of Horse Chestnut causing noticeable brown blotches, often many to one leaf, often resulting in complete defoliation of a tree, over-wintering as a pupa in a cocoon. There is however, a similar-looking fungus which can cause confusion.