The ranger of Chorleywood Parish Council (CPC) is warning residents after a breed of insect that is dangerous to both humans and dogs was recently spotted on the Common.
The oak processionary moth (OPM) is an invasive species first identified in London in 2005, after having come over from mainland Europe. They were first sighted on the Chorleywood Common back in 2021, having been in nearby Watford for some time.
The danger comes from the caterpillars, which can cause severe allergic reactions in both dogs and humans. Their nests look like patches of dense spiderwebs and attach themselves to trees. If left, they break up and drift into the wind, making it easier for them to cause allergic reactions.
The nests are set to be removed, requiring specialist contractors wearing protective equipment. Pesticides are not used when dealing with the OPMs, as they are ineffective and leave the nests behind. Usage may also result in the death of other insects in the spray area, such as butterflies.
CPC Conservation Ranger Daniel du Gard said: “OPM is unlikely to be eradicated from the UK and as the effects of global warming take hold it is quite likely to spread across the country.
“We are likely going to have learn to live with them as a normal feature of our parks and woodlands.
“To keep safe, people should ensure they know how to identify OPM caterpillars and their nests and thoroughly inspect a tree before interacting with it. Dogs should be kept on short leads.”