The Oak Processionary Moth

By Helen Elks-Smith.

Oak processionary moth (OPM) was first found in south-west London in the summer of 2006 and was probably brought in on infected oak trees from Europe. The caterpillars feed on oak leaves and can strip the tree bare, leaving it vulnerable to other pests and diseases and less able to withstand extreme weather conditions such as drought and flood.

The caterpillar is also a problem to people pets and wildlife. The caterpillars have thousands of tiny hairs which can be blown on the wind. These hairs contain an irritating substance ‘thaumetopoein’ which causes irritation and rashes on contact, and in some cases sore throats, eye problems and breathing difficulty.

Webnest

At the moment OPM remains confined to sites in the South and West of London and one in Berkshire, although scientists believe that it could survive and breed in much of England and Wales. It is imperative that we act now to protect our open spaces and prevent OPM from spreading to the wider landscape of England and Wales.

Biosecurity measures to help contain and possibly eradicate OPM include tree passports for imported oak trees and restrictions on tree movement in infected areas. Infected trees are treated with a combination of surveying, spraying and manual nest removal.

To be successful these biosecurity measures need to be fully enforced and you can help. If you visit an affected area, take care to ensure that you do not bring anything away with you that may spread the infection (such as plant matter , twigs and branches) If you already have oak trees on your property, survey them regularly for signs of the nests and caterpillars so any infection can be caught early before it spreads. If you are planting new oaks, make sure they are from reputable suppliers and, if from abroad or infected areas in the UK, that they have a plant passport

webtrailIf you think I have seen OPM caterpillars or nests:
Do not touch or approach caterpillars or nests.
Keep people away away from nests, caterpillars and affected trees.
See a doctor or vet if seriously affected by symptoms.
Report sighting (with photo if possible) to local council or Forestry Commission
For further information visit www.forestry.gov.uk/opm
Landscape and garden designer Helen Elks-Smith is a BALI Design Excellence award winner based in the New Forest. She feels passionate about conservation and the future of our landscape. Helen has teamed up with sponsor’s The City of London Corporation, to design a garden for RHS Chelsea Flower Show 2014, to raise public awareness of the threat of oak processionary moth and the importance of biosecurity measures to contain it.