Across the Irish Sea they are aware of the risks posed to their horse-chestnut trees, according to an article in the Irish Times by the naturalist Michael Viney.
Whenever it arrives, it will almost certainly come across in someone's car,
crossing on the ferry. My guess would be that it will be first found in a town
near a port in south of the island (maybe Cork or Dublin) in about 5 years'
time. It could easily come from someone in a town in England or Wales who was
packing their car boot under a horse-chestnut tree and some of the moths got in
the boot but by mistake, survived the journey and they escaped when the car was