Caterpillars bristling with thousands of toxic hairs are increasingly making London their home, despite serious efforts to control them.
The caterpillars are the offspring of the Oak Processionary Moth – a large brownish grey moth which is typically found in European oak forests.
The grey bristles on the caterpillars are easily shed and can cause skin, throat and eye irritation in humans.
Infestations were first recorded in the UK in 2006, after possibly arriving on imported oak trees to south London. It is thought that a warmer climate has allowed the moths to survive further north than previously possible.
In 2013, the Forestry Commission used helicopters to “blanket spray woodlands”, the Telegraph reports, but numbers have still proliferated.
According to the Evening Standard, about 30 pupils at a south London school suffered rashes through contact with the caterpillars, but none developed long-term health problems as a result.
Larvae construct silk nests in oak forests, and when night falls, exit the nest in single file, and march nose-to-tail up the trees to reach the leaves.