Horse chestnut leaf miner - cameraria ohridella

 

The horse chestnut leaf miner (Cameraria ohridella) was first observed in Macedonia, in northern Greece, in 1985 and was described as a new species in 1986. In 1989, it appeared unexpectedly in Austria and since then it has spread throughout central and eastern Europe. It was first found in Great Britain in 2002 in the London Borough of Wimbledon. Over the last two years its range has expanded, and it can now be found at many locations in south-east England.

Experience from Europe indicates that once established, the moth will cause severe damage to the foliage of horse chestnut on an annual basis, and defoliation before normal leaf-fall in the autumn. The larvae mine within the leaves and at high population densities they can destroy most of the leaf tissues. Damage can be reduced by removing fallen leaves during the autumn and winter and either composting them thoroughly, to destroy the over-wintering pupae, or if the leaves are collected into smaller heaps, by covering them with a layer of soil or other plant material to prevent adult emergence in the following spring.

Further information on C. ohridella in Great Britain, including its current distribution.