Parasitic “hitchhiking” moths, which infect and destroy the leaves of horse chestnut trees, are moving north and could soon invade Scotland. The horse chestnut leaf-mining moth, which originates in the Balkans, was first recorded in London in 2002 and has spread throughout England and Wales.
Dr Darren Evans, an expert in conservation biology at the University of Hull and a co-founder of Conker Tree Science, said “it’s only a matter of time” before the species expands further north into Scotland. The invader feasts on the leaves of the conker-producing trees, turning them brown and causing them to drop in the late summer.
Evans said several million of the caterpillars could be present on each infected tree, adding: “It looks like autumn has come early for the trees. When the leaves have been destroyed, they tend to drop early.”There is little evidence that the moths can kill horse chestnut trees, but Evans said there were fears they could weaken the tree’s immune system and make them more susceptible to disease, including bleeding canker, a bacterial disease that creates leaking lesions on the trunk.