Image credit: Press Association

Victims of a invading caterpillar in London and Surrey have been told to seek treatment from their pharmacist for relief from skin and eye irritations, vomiting and breathing difficulties.

The Forestry Commission has warned people to watch out for the toxic larvae of the Oak Processionary Moth (OPM), which originated in Europe and come to life in late spring.

The environmental department has identified the OPM caterpillars living in oak trees in more than 600 sites in the London area which will be treated with a biopesticide to eradicate the infestation and prevent future outbreaks. Additional sites outside of this ‘control zone’ are reportedly being dealt with by local authorities and tree managers.

The caterpillars have long, white hairs which contain a protein called thaumetopein that causes irritation, sore throats, breathing problems including asthma attacks and sickness. These hairs can be shed in defence and are also found in nests or carried in the wind.

What are OPM catepillars?

OPM caterpillars have been seen emerging from egg plaques last month. The Forestry Commission warned that during May the caterpillars will become larger and descend from the trees.

OPM caterpillars create distinctive webbing nests which can reach several feet in size on the trunks and branches of oak trees. Feeding on the oak leaves they also strip the plants making them vulnerable to attacks from other pests and extreme weather conditions.

The creatures were first discovered on British soil in 2005, believed to have entered the country from continental Europe as eggs on live oak plants. The southern Europe native has since been spotted in several boroughs in the London region, most recently Thurrock in Essex (2017) and Watford, Hertfordshire (2016).

The Forestry Commission has urged people not to touch the caterpillars or their nests and to report any sightings through the tree alert tool providing a precise description of the location.