Public warned to watch out for ‘rare toxic caterpillar’ spotted in UK

Forestry Commission / Henry Kuppen

The Forestry Commission has urged members of the public to be on high alert for potential sightings of a toxic caterpillar know as the Oak Processionary Moth (OPM).

The caterpillars of OPM are known to be the pests of oak trees and “a hazard to human and animal health”.

They feed on oak leaves, can strip whole oak trees bare when in large populations and their presence can also increase a trees’ vulnerability to attack by other pests and diseases as well.

The Oak Processionary Moth (OPM), scientifically known as Thaumetopoea Processionea, was first identified in London back in 2006. It has since then believed to have spread to the surrounding counties and was spotted last year in Cambridgeshire, Hertfordshire, Essex and Lincolnshire.

According to The Forestry Commission, OPM caterpillars and their nests contain hairs which should not be touched under any circumstances at any time. If someone should find themselves coming into contact with the OPM, they may experience side effects ranging from vomiting, skin rashes and eye/throat irritations, to life-threatening asthma attacks.

The greatest OPM risk period in the UK is between May – July, as this is when the caterpillars tend to emerge and feed, before then pupating into adult moths.

Ross Crabb

The OPM caterpillars can be identified by their characteristically black heads and bodies that are covered in long white hairs. Their nests are also typically dome or teardrop-shaped and tend to average the size of a tennis ball.

Andrew Hall, Operations Manager at the Forestry Commission Operations Manager, said: “At this time of year, many people are enjoying green spaces and it’s really important for the public to be aware of the risk of tree pests like Oak Processionary Moth and to report any sightings via our TreeAlert website or by calling the Forestry Commission.”

“This will help us with our programme of treatment and enables us to slow the spread of this pest.”

A government programme, headed by the Forestry Commission to limit the whereabouts of the OPM, is currently in place. Any sightings of the OPM by members of the public should be reported to the Forestry Commission TreeAltert online portal here.

Alternatively, you can email opm@forestrycommission.gov.uk, or call 0300 067 4442.

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