May 8 2018
The Oak processionary moth (OPM) has thousands of toxic hairs over its body which it can eject. These hairs contain an irritating substance called thaumetopoein which, if come into contact with, can cause fevers, eye irritation, skin rashes, trigger asthma attacks and vomiting. The toxicity of the hairs can stay active for up to five years after being ejected from the caterpillar.
Infestations of OPMs were recorded in Greater London but have been spotted in the surrounding areas as far as Bracknell Forest, Brent and Guildford.
You can recognise OPMs by their long white hairs, distinctive habit of moving in nose-to-tail processions, often forming arrow-headed processions with one leader and more following in rows behind, and are mostly seen in late spring to early summer. One thing to note is that you will not find them living on fences, walls or similar structures as some other harmless caterpillar species do.
The caterpillars are most likely to be found in and around oak trees and are often clustered together as they feast on oak leaves. Under no circumstances should you, a child or an animal touch these caterpillars or their nests, and any attempt to remove the species should be done by a professional pest control expert.
If you do come into contact with the caterpillars, speak to your local pharmacist for relief from skin or eye irritations, or call NHS 111 if you think you or someone you are caring for have had a severe allergic reaction. If your pets have been seriously affected, speak to your vet.