Oak Processionary Moth

14 May 2010

The Environment Division Plant Health Laboratory is once again reminding people not to touch the caterpillars of the oak processionary moth (OPM) that are now likely to be hatching in oak trees in the Island.

Islanders are also being asked to report any sightings of these creatures. The caterpillars, which are the larval life-stage of the moth, are pests that damage oak trees by feeding on the leaves. Their tiny, toxic hairs can cause painful skin rashes and irritations to eyes and ears and, in severe cases, breathing difficulties if they are inhaled. Animals can be similarly affected.

The best time to control the problem is in the spring, after the caterpillars have hatched, and in the summer when they gather in their distinctive white, silken nests to pupate into adult moths. During the next few weeks, staff from the Environment Department, Parish of St Helier and Transport and Technical Services will be checking oak trees in public areas.

Any infestations found will be dealt with by specially equipped and trained operators. Later in the summer, the operators will also remove and destroy nests made by any remaining caterpillars which would pupate in the nests before re-emerging as moths.

Head of the Plant Health Service, Scott Meadows, said the public could help “Initially the nests can look like a small lump of flattened, white, silky candyfloss, approximately the size of the palm of one’s hand, adhering to the trunk or branch of a tree.

“As the caterpillars grow, so does the nest. It darkens in colour to tan or brown, and silky threads can be seen leading from the nest up the tree limbs to where the caterpillars feed on the foliage further up, returning to shelter in the nest after feeding.

“We welcome reports of sightings of the caterpillars or their nests from the public, gardeners and tree surgeons. However, we strongly advise people not to touch or approach the caterpillars or their nests because of the health risks that the toxic hairs pose. Nor should they try to treat the caterpillars or remove the nests themselves before taking advice from us.”

Sighting reports and photographs can be sent to Plant Health Team, Environment Division, by calling 441600 or emailing s.meadows@gov.je

Health advice

Anyone who is worried by an itching skin rash, conjunctivitis, increased asthmatic or other symptoms, and who might have been near oak trees harbouring oak processionary caterpillars and their nests, should consult their GP.