Ecologists are sounding the alarm over the growing presence of oak processionary caterpillars, a toxic species that poses risks to both humans and animals, as populations expand beyond their known habitats in London and the South East.
These caterpillars – the larval stage of the oak processionary moth – are named for their habit of moving in nose-to-tail processions.
They are covered in tiny hairs that contain a potent toxin, which can cause skin irritation, sore throats, eye problems and even respiratory issues in people. Dogs and other animals may also be affected.
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The threat is greatest in early to mid-summer, when caterpillars build distinctive white, webbed nests on oak trees in parks, woodlands and gardens.
Originally introduced to the UK via imported trees, oak processionary moths have become a seasonal concern. Ecologists at Arbtech are urging the public to remain vigilant as the species continues its spread north and west.
If you spot a caterpillar procession or one of their nests, avoid contact and report it to the Forestry Commission.
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Top image: An oak processionary caterpillar, Thaumetopoea processionea (credit: Getty Images)