As part of the work to support the Oak processionary Moth Outbreak Management Team a Pest Risk Analysis (PRA) was been prepared. This forms the supporting evidence for action by the Forestry Commission under EU and UK plant health legislation:
Pest Risk Analysis record for Thaumetopoea processionea (PDF-181K)
The key conclusion from the PRA is that oak processionary moth justifies being classified as a pest of phytosanitary concern and that the main pathway for longer distance dispersal, especially between countries, is on live plants for planting of hosts of the moth, principally oak trees.