Oak processionary moth, Thaumetopoea processionea, originates from southern and central Europe. It is one of a number of insect pests that may be able to colonise the UK more readily in a warming climate.
Caterpillars of the moth were first found in Britain in west London in 2006; they are likely to have been introduced with imported oak trees. Since then the pest has been found in other areas of Greater London.
Symptoms and control
The moth’s caterpillars can cause severe defoliation on a wide range of native and exotic oaks (Quercus spp.). They are gregarious, present from April to early July, and are greyish black, covered with long whitish hairs. They feed mainly at night, sheltering in silk webbing during the day. The hairs on the caterpillars’ bodies readily break off and can cause allergic skin rashes and irritation to the eyes and throat in people, cats, dogs and horses that can be severe.
Infestations to date have been destroyed to prevent the moth becoming permanently established in Britain. For more information see the Forest Research website.
Anyone suspecting they have found this pest should report the location to Forest Research (Tree Health Division). Tel: 01420 22255, or e-mail: research.info@forestry.gsi.gov.uk.
The caterpillars and their webs should not be handled
without protective clothing
because of the irritant hairs