Caterpillars which are toxic to humans and pets and can cause asthma attacks and fevers are invading UK
Health experts warn you don't even need to touch them to be affected as their hairs can travel in the wind
A PLAGUE of toxic caterpillars that can bring on asthma attacks and even strong fevers are invading the UK.
The toxic bugs, called oak processionary moths (OPM), began to infiltrate Britain last week with reports emerging that hotspots were cropping up across the south east of England.
Now wildlife experts are telling people to report nests as soon as they spot them - in an attempt to stop them spreading nationwide.
The creepy crawlies - which are highly toxic in their caterpillar stage - first invaded the UK from mainland Europe in 2005 after oak trees were imported from Holland.
The critters pose a hazard to humans, pets and livestock.
Hairs on the caterpillars contain toxins called thamentopoein which can cause severe skin rashes and asthma attacks as well as causing eye and throat irritations, vomiting, dizziness and fever.
But health boffins have warned that you don't even need to touch them to be affected as their hairs can be carried in the wind.
The oak processionary moth lays its eggs on oak trees and its larve leave their nests to feed on oak leaves.
Once they have stripped a tree bare they move on to the next tree - following one another in a procession, hence their name.
The nests - which are white and the size of a tennis ball - contain hundreds of caterpillars, which are about two-inches long.
The Forestry Commission issued an alert last week, saying that it is not just humans that are at risk, but also pets and farmers' livestock.
Symptoms that cats and dogs have been affected include; hyper-salivation, swelling of the tongue, conjunctivitis, gagging, vomiting, respiratory distress and inflammation of the mouth.
A spokesman said: "The larvae, or caterpillars, of the oak processionary moth (OPM) are a hazard to tree, human and animal health.
"They are emerging in oak trees in the affected areas of London, Surrey and Berkshire.
"Carefully controlled treatment of affected trees with approved insecticide to kill the caterpillars is under way.
"Those that survive treatment will grow big enough and descend low enough in the trees to be seen and recognised by the naked eye by early May.
"May is also about the time when they develop the hairs which contain a substance which can cause itching skin rashes, eye irritations and, occasionally, sore throats and breathing difficulties in people and animals who come into contact with them."
To report a nest, logon to //www.forestry.gov.uk/treealert
Public Health England has warned anyone affected to call their GP or NHS 111.
In 2013 the Forestry Commission used helicopters to blanket spray woodland areas where the caterpillars posed a health threat.
In Belgium, the annual invasion of toxic caterpillars has become so serious that the army has been sent in to incinerate the caterpillars' nests.