As of 21 August 2018, legislation from DEFRA will aim to protect oak trees within the UK from the Oak processionary moth (OPM). This is also know as, Thaumetopoea processionea. The move follows a recent interception in trade of OPM from the Netherlands to the UK.
The precautionary measures are necessary due to the risk posed to native oak trees, humans and some animals. This is whilst the oak processionary moth is in its caterpillar life stage. The risks are twofold:
- As a caterpillar, oak processionary moths are capable of defoliating large areas of oak trees. This leaves target trees vulnerable to other, external stresses, such as disease, drought or flooding.
2. The caterpillars have thousands of hairs which, when in contact with human or animal skin, can cause unpleasant rashes. In isolated cases, the hairs can cause more serious issues such as sore throats, breathing difficulties and eye problems. The hairs are also commonly found in the nests they live in.
As a result of this risk, legislation will commence to prohibit the movement of plants into OPM protected zones. This is unless they meet specific criteria.
What legislation is being introduced?
Legislation will apply to movement of all Oak trees (except for Quercus suber) with a girth at 1.2 metres above the root collar of 8cm or more, into OPM protected zones unless they meet specific conditions. The legislation states imports into and movement within OPM protected zone are only permitted if oak specimens:
- Have been grown in places of production in countries in which Thaumetopoea processionea L. is not known to occur;
- Have been grown in a protected zone, recognised as an area free from Thaumetopoea processionea L. Established by the national plant protection organisation under ISPM No. 4;
- Produced in nurseries which, along with their vicinity, are free from Thaumetopoea processionea L. On the basis of official inspections carried out as close as practically possible to their movement and official surveys of the nurseries. Their vicinity must be carried out at appropriate times since the beginning of the last complete cycle of vegetation to detect larvae and other symptoms of Thaumetopoea processionea L.; or
- Grown in a site with complete physical protection against the introduction of Thaumetopoea processionea L. They are inspected at appropriate times and found to be free.
Where is the OPM protected zone?
England is known to be a protected zone, except for the following local authority areas (currently around London and the south):
- City of London
- City of Westminster
- Epsom and Ewell
- Hammersmith and Fulham
- Kensington and Chelsea
- Kingston upon Thames
- Richmond upon Thames
- South Oxfordshire
- Tower Hamlets
- West Berkshire
As part of the legislation, any plants destined for a protected zone must be accompanied by official documentation. This must confirm that they are free from the oak processionary moth.
What about Oak trees with a girth at 1.2 metres above the root collar of less than 8cm?
These trees represent significantly less risk of concealing OPM, and are not subject to these restrictions.