TOXIC caterpillars that cause agonising rashes, vomiting and breathing problems are invading the UK.
Brits should be on alert for oak processionary moths, which are poisonous in their caterpillar stage, as they "pose a threat to human health", experts warn.
The hairy bugs can cause nasty swelling, painful rashes, itchy eyes, throat irritation, vomiting, dizziness, fever and asthma attacks.
Symptoms usually occur from direct contact, but the tiny hairs can also be blown by the wind, fall to the ground, stick to trunks, branches, grass, clothing and equipment.
Nests are normally tennis ball-sized and white when fresh before turning brown as they age.
Clusters of the caterpillars, which have black heads and are visible until the end of July, have been spotted in Long Eaton, Derbyshire.
Several infestations in oak trees have been confirmed, though officials have not specified exactly where.
They insist "swift" action is being taken to curb the spread, and any further sightings should be reported as soon as possible.
Nicola Spence, UK chief plant health officer at Defra, told DerbyshireLive: "The oak processionary moth is an insect pest of oak trees and poses a threat to both plant and human health.
"We are taking swift and effective action to treat the infested trees and eradicate the pest from this area, and prevent further spread in the surrounding area.
"The government takes the management of the moth very seriously and has a robust programme in place to reduce the level of pest prevalence and protect oak resource, whilst supporting landowners to manage the risks associated with the moth in the areas where it has been identified."
Much of southern England has been conquered since the pests arrived at Kew Gardens in South West London on a shipment of trees in 2006.
The rate of the spread appears to have quickened in the last few years.
In 2022, the number of "attacks" topped 100 for the first time.
Some 225 people were poisoned by oak processionary moth hairs last year — four times the 56 in 2021.
The Forestry Commission, which sprays dozens of sites in a bid to kill off the moths, warned: "Don’t approach them or try to remove them."
Anyone who spots the moth or caterpillar should report it on [email protected] or 0300 067 4442.
How to identify oak processionary moths
THE caterpillars have black heads and grey bodies covered in long white hairs.
They are only about 2mm long when they emerge in spring, and tend to remain high in the trees until they are older and larger.
When they reach 1cm long, they develop the irritating hairs. They’re fully grown at 2cm long.
They usually move nose-to-tail in a procession, hence their name.
You may be able to see them on all parts of the tree - on the trunk, branches and leaves, and occasionally on the ground.
Nests are usually found in early summer, in the trunks and branches of oak trees at any height.
They are typically dome or teardrop-shaped, and range from the size of a golf ball to a rugby ball.
When fresh, the nests are white with white silken trails made by the caterpillars along the branches and leaves.
But the nests soon become discoloured and brown, making them harder to spot.
Source: Forestry Commission