Landscapers, nurseries, landowners and woodland managers are being urged to take action after the Plant Health Service intercepted a number of cases of Oak Processionary Moth caterpillars (OPM) on trees imported from the Netherlands.
Anyone who has planted larger oaks (defined below) imported from the Netherlands and continent should urgently check their trees for OPM and report any findings to TreeAlert. It is vital that these trees are checked now to minimise the spread of this damaging tree pest and protect the health of our oak trees.
OPM is an established pest in parts of London and surrounding areas, but the rest of the country is designated as a Protected Zone.
Swift action is being taken by the Plant Health Service to eradicate recent findings of OPM in Hampshire, Warwickshire and Gloucestershire. This includes surveillance, tracing work and destruction of both the caterpillars and infested trees. The Plant Health Service has also announced an urgent review of import controls on oaks.
OPM caterpillars feed on oak leaves and can increase trees’ vulnerability to attack by other pests and diseases, making them less able to withstand weather conditions such as drought and floods. The cases highlight the need for continued vigilance from industry and government to protect the UK’s trees.
The Forestry Commission, councils and land managers tackle the pest with an annual control programme of tree treatment. Increased measures to protect the country from the spread of OPM were introduced in 2018. Restrictions on the import of most species of oak into England have also been introduced as part of these regulations to protect native trees.
If you suspect OPM, you should not attempt to destroy or move infected material yourself as the nests and caterpillars can pose some risks to human health. For more on how to identify OPM, visit the Forestry Research website.
Larger oaks are defined here as those with a girth >8cm at 1.2m above the root collar.