Hairy caterpillar warning
Oak processionary moth nests considered a hazard to human, animal and tree health
The hairy larvae could currently be building its nests in oak trees in the south of the county and both the catterpillar and its home are considered a tree, human and animal health hazard.
People are also being advised to protect animals from contact with the nests, and to report sightings to the Forestry Commission.
Oak processionary moth (OPM) caterpillars shed thousands of their tiny hairs in the nests, and these can cause itching skin rashes and eye irritations and, more rarely, breathing difficulties in people and animals. The caterpillars are considered a tree pest because they eat oak leaves: large numbers can strip oak trees bare, leaving them weakened and vulnerable to other threats.
The caterpillars build their distinctive white, silken, webbing nests and trails in June on the trunks and branches of oak trees, anywhere between ground level and many metres high. The nests become discoloured after several days, and harder to see as a result. They can also fall out of trees, creating a hazard to curious children and pets, and grazing livestock.
Alison Field, the Forestry Commission’s South-East England director, encouraged local people to help tackle the pest by reporting sightings of the nests and caterpillars, but not to touch or approach them.
“We want to keep our woods, parks and gardens safe for everyone to enjoy,” she said. “The public can help us by reporting OPM nests and caterpillars to us so that they can be properly removed.
“However, please don’t try to remove the nests yourself. To be as effective and safe as possible, this job needs to be timed just right and done by people with the right training and equipment, and the nests must be disposed of properly.”
Dr Deborah Turbitt, London deputy director of health protection for Public Health England, endorsed the ‘don’t touch’ message, adding: “We strongly advise people not to touch or approach the nests or the caterpillars because of the health risks, but to see a pharmacist for relief from milder skin or eye irritations if they do come into contact. Consult a GP or NHS111 for more serious reactions, and contact a vet if pets are badly affected.
“We have issued advice to local GPs and health professionals to help them identify when patients have been affected by contact with OPM hairs, and to advise them on appropriate treatment.”
Sighting reports can be made with the Forestry Commission’s Tree Alert on-line form available from www. f ore s t r y . g ov. uk/ opm1, or by email to firstname.lastname@example.org.
The nest of the oak processionary moth caterpillar
the nest as it begins to disintegrate