Biologists suit up for battle against Kew's toxic caterpillars

Toxic caterpillars spreading across west London are being hunted and destroyed at Kew Gardens this week by experts in protective gear.

The insects are covered in up to 62,000 long grey hairs that can produce rashes and sore throats in humans, and in some cases cause anaphylactic shock, which can prove fatal.

Biologists wearing body suits and breathing apparatus are removing up to 500 nests from the Royal Botanic Gardens' oaks and incinerating the larvae before they can become moths.

The oak processionary moth was accidentally imported from southern Europe into Kew village about four years ago in a batch of infected trees. The invader has since spread to Richmond, Hounslow and Ealing.

The caterpillars feed on oak leaves and, if left unchecked, can defoliate entire trees. The insect's name comes from the caterpillars' habit of moving together in long columns.

Tony Kirkham, head of Kew's arboretum, said: "The first year there were three nests, last year there were 145 and this year there are 500."

He said visitors to Kew were safe because the nests were mostly far above head height and any found lower were being destroyed.

Anyone who finds a nest should avoid contact with the caterpillars and call their council.