The OPM caterpillars are oak processing moths which feed on oak leaves, and large populations can strip trees bare, leaving them weakened and vulnerable to other threats have arrived in the UK. They can also affect the health of humans, plants, and animals. The caterpillars contain thaumetopoein, the irritating protein found in the hair can cause asthma attacks, eye irritations, sore throats, breathing problems, vomiting, and skin rashes.

The caterpillars are spotted across London and the south-east UK. The Forestry Commission has issued a notice not to go near the species. The biggest infestation of the species has been recorded in the Greater London, Bracknell Forest, Slough and Guildford. Although, the greatest risk period is May to July nest should not be touched at any part of the time because the detached hair can cause harm.

Every caterpillar has 62,000 hairs, which they can shed. The moths only live for two to three days between May to July but their hairs can be active for up to 5 years. The people generally think that these moths had been brought to the UK on trees imported from Europe for a landscape project. These caterpillars can be easily recognized by their different habit of moving in late spring and early summer in nose-to-tail fashion and they live mostly in oak trees.

The contact with caterpillars would lead to many problems and this can happen if a person or animal touch the caterpillars or their nests. Contact might also happen through the wind. These caterpillars also shed their hair in the nest as a defense mechanism that is why nest should not be touched with the naked hands or without any protective clothing.

OPM caterpillars are threatening the health of several oak species because they feed on them. They are making them more vulnerable to the other pests and diseases.

People of affected areas can follow these precautions to minimize the impact of it:

  • Do not try to touch the nest
  • Keep children and animals away from the nest
  • Don’t try to remove nest by yourself