Urgent “do not touch” warning on the caterpillar, which poses a risk to human health

People have been warned not to touch a caterpillar as it could make them sick. The Forestry Commission has warned the public to be alert to oak processionary moth caterpillars, a pest that not only damages trees but also poses risks to human health.

This alert comes at the start of the peak risk period for this non-native species, which is found mainly in south-east England, having been introduced from Europe by mistake with trees imported for planting. The caterpillars, known for their distinctive nose-to-tail marching formation, feast on oak leaves during their migration, affecting the tree’s growth and making it more susceptible to other stressors such as drought and disease, according to experts .

The hairs of oak processionary moth caterpillars, as well as their nests made of white silk web, can cause itchy rashes, eye and throat irritation, and are strictly advised against touching. The public is also strongly discouraged from attempting to remove the nests, which are usually located on the trunks or branches of oak trees.

Andrew Hoppit, Oak Processional Moth Project Manager, emphasized the importance of awareness, saying: “It is important that those who live and work in areas affected by oak processional moths remain vigilant about the health risks they pose when enjoy the outdoors as we enter the period of greatest risk.”

First detected in London in 2006, the bug has spread to nearby counties in the South East. Professor Nicola Spence, the UK’s Chief Plant Health Officer, said: “Oak trees are an iconic and much-loved part of our British landscape.”

Adding further, she explained: “By reporting any sightings of the oak processionary moth to the Forestry Commission, we can all minimize the spread of the pest as well as its impact on tree health.” She also advised the general public, particularly those living in London, surrounding areas and Derbyshire, to avoid any interaction with the caterpillar and its nests as it can cause irritation.

People have been asked to report sightings of oak processionary moths either through the TreeAlert website at https://treealert. forestresearch.gov.uk or by email at [email protected].