Attacks on trees by invasive pests and pathogens, if left uncontrolled, can cause significant damage to the forestry industry across the UK, primarily the spruce and timber industries. However, values at risk extend beyond commercial woodland and forest industry, including natural forests and urban trees. These resources are essential to a healthy, biodiverse environment, which in turn provides key ecosystem services and benefits to human health. Infestation by some pests, such as the emerald ash borer, can be fatal to trees, and once established can cause significant harm to woodland biodiversity and ecosystems, as well as the timber industry.

This document is an Annex to the Welsh Plant Health Surveillance Network Programme 2022 Review, and reports on the second year of the WPHSN activities undertaken on behalf of the Welsh Government. It describes a network of insect and spore traps placed at strategic woodland sites across Wales to monitor and record the presence/absence of invasive pests and pathogens which may negatively affect our trees, woodlands, and forests.

Details are given of the project objectives, the key biological threats being monitored, the trapping and analysis methodologies, interim results from the 2023 trapping season, and recommendations are made for 2024 and beyond.