The caterpillars of the Oak Processionary Moth, which can also cause itchy rashes and breathing difficulties, are easily recognisable because of their long white hairs and the way they travel in nose to tail processions.
Neighbouring borough, Hounslow Council is warning the public to avoid contact with the caterpillars and is urging people to report sightings to the Forestry Commission’s Tree Alert service to help with a national effort to stop their spread.
The caterpillar nests are usually found on oak tree trunks or branches which can occur in rounded and sometimes hammock-like nests that resemble a greyish bundle of cotton.
If left unchecked, the invasive species can decimate oak trees by stripping them of their leaves, resulting in bare trees that are more open to disease and other pests.
Hounslow Council’s tree management team GreenSpace 360 removed caterpillar nests earlier this month and further removals are expected to take place from mid-July when nesting is expected to intensify.
Hounslow Councillor, Samia Chaudhary, Cabinet Member for Leisure Services, said: “I know many of you will be enjoying spending time in the borough’s beautiful parks and other green spaces with oak trees over the summer, but I urge you not to approach these caterpillars or their nests if you spot them and to prevent children from doing the same.
“It’s also advisable to minimise spending time under or in the downwind of any infested oak tree, especially on windy days during the summer.
“It’s important that residents should not attempt to remove the nests themselves. Please report any sightings using the Tree Alert service and be assured that Hounslow Council’s tree management team is working very hard to manage this problem.”
To report a sighting, go to the Tree Alert service by visiting treealert.forestresearch.gov.uk.