Oak Processionary Moth (OPM)
OPM is a species of moth native to Southern Europe which was accidentally introduced to England in 2005-2006 and has since spread to the counties around London.
The caterpillars construct white webbing nests on trunks and branches of oak trees which resemble candy floss or cotton wool.
The caterpillar of this moth emerges in April every year and their tiny hairs can pose a health risk to humans and pets. The risk of exposure to these hairs is highest in May and June.
If you do come in contact with the caterpillar or its hairs please follow the NHS health advice.
See Forestry Commission interactive distribution map to see affected areas.
All sightings of the oak processionary moth should be reported to the Forestry Commission immediately.
Types of oak affected
Oak Processionally Moths (OPM) live almost exclusively in the following types of oak trees (Quercus):
Method of Treatment
There are two main options for dealing with the pest:
- Manual removal of nests.
- Pesticidal treatment: this is only suitable for early-stage caterpillars. The Forestry Commission may offer support for this.
It is the protein in the caterpillar hair which can cause irritation and allergic reaction in people and pets. In addition to being on the caterpillar the hairs may be loose or left in the active or dormant nest.
Symptoms to exposure to the hairs may include:
- Itchy skin rash
- Eye and throat irritation
- Occasional breathing difficulties
- In rare cases allergic reaction
Please follow the NHS health advice in the event of symptoms following exposure.
Nest removal procedure
⚠ DO NOT TRY AND REMOVE THE CATERPILLARS OR NESTS YOURSELF. ⚠
- Full PPE must be worn by operatives in the tree where OPM is present including boiler suits, face masks, head covering, gloves etc. This PPE will be disposed of as bio-hazard waste following the removal operation.
- Special OPM climbing kit will be used. This will be throughly cleaned after each removal and disposed of at the end of each season. This special OPM kit is not used for any other tree operations to avoid cross contamination.
- Nests are sprayed with adhesive to ‘set’ the hairs to the nest and avoid contamination to workers, kit, and the surrounding area.
- Nests are removed and controlled and are then dealt with as bio-hazard waste and sent off for incineration.
How we charge for nest removal
OTT offer nest removal where appropriate for an hourly rate. We will happily provide an estimate before commencing work.
Please enquire for our latest nest removal rates.
OTT do not offer pesticide spraying treatment at this time.