Secondly, please do not try to remove the caterpillars or nests yourself. They need to be removed by an Arborist who has had the correct training and has the necessary equipment required. The nests must also be disposed of properly to avoid the pest spreading.
Areas Affected by OPM
Originally native to the Mediterranean regions of Europe, the oak processionary moth is now well established in a number of countries including Germany, Belgium, and Holland. The caterpillars were first found in London in 2006 and government studies show the pest spreading on an annual basis. As the map indicates, OPM is now established throughout much of greater London and some surrounding areas.
If you are looking to have your property treated by a professional, find a local Bartlett Tree Experts' office near you. Bartlett covers most areas in the UK that are affected by OPM, including the entire Greater London area.