The warm weather has brought a public warning about a caterpillar pest that causes eye and skin irritation.

Romford Recorder: Trail of the OPM caterpillars that damages oak trees in our parks and open spaces. Picture: Henry KuppenTrail of the OPM caterpillars that damages oak trees in our parks and open spaces. Picture: Henry Kuppen (Image: Henry Kuppen/Forestry Commission)

The caterpillar, which turns into the oak processionary moth, first appeared in east London in 2016 after spreading along the Regent’s Canal from Regent’s Park.

Nests were spotted in Bethnal Green Gardens, Victoria Park, Olympic Park and Mabeley Green which had to be sprayed to prevent damage to oak trees.

But now, four years on, the Forestry Commission warns the sunshine has brought them out yet again.

Romford Recorder: Spraying by Forestry Commission contractor to control spread of OPM pest. Picture: Henry KuppenSpraying by Forestry Commission contractor to control spread of OPM pest. Picture: Henry Kuppen (Image: Henry Kuppen/Forestry Commission)

“It’s important to be aware of the risk of tree pests like the oak processionary moth,” the Forestry Commission’s Andrew Hall warned. “We are asking people to report any sightings to help slow the spread of this pest.”

The nests contain hairs which can be blown on the wind and cause rashes and eye and throat irritations. The risk period is May to July when the caterpillars emerge before turning into moths that feed on oak leaves, which can make trees unable to withstand drought and flooding.

The OPM is thought to have been introduced accidentally when oak trees were imported from the Continent in 2005 with undetected moth eggs smaller than pin heads.

It appeared at Richmond Park, then spread to Regent’s Park and across London and the Home Counties, along the Regent’s Canal to Victoria Park and along the Lea River and the Olympic Park.

The public is being urged to report any sightings to the Forestry Commission online, or call 030-0067 4442.