The recent interception of Oak Processionary Moth (OPM) in Dublin highlights how pests can move across borders. OPM is a plant pest, primarily of oak (Quercus) trees. The adult moths and juvenile caterpillars can cause defoliation of oak trees. More importantly, the juvenile caterpillars can be injurious to human health as they release microscopic hairs when disturbed, which can cause skin irritation and breathing difficulties. The OPM found on an oak tree in Dublin was eradicated immediately and the trees which had been planted were destroyed. As a result of the threat this pest poses, the Government introduced new legislation in January 2020 to prevent its introduction into Ireland. This Order requires any person bringing Quercus plants or trees into the State to notify the Department of Agriculture, Food and the Marine in writing at least two days in advance at the following email address: plantandpests@agriculture.gov.ie.