Most unwanted: Oak Processionary Moth Caterpillars

From around April, this area is home to oak processionary moth caterpillars. They can cause skin and eye irritations and breathing difficulties if you or your animals come into contact with them.

Oak processionary moth caterpillars are present on this site. They can be seen clustered in large groups on oak trees. 

These hairy caterpillars are not native and can cause quite unpleasant irritation and swelling to the skin, eyes and throat of humans, horses and dogs. So whilst the caterpillars may look interesting and fluffy please refrain from touching them. It is advised that you keep your dogs on a lead to avoid contact with these caterpillars and their nests.

The ranger team will be working with contractors to try to manage this issue. Our plan over the coming months is to physically remove nests from all trees currently identified as containing OPM in accordance with Forestry Commission guidelines.

We will also survey all oak trees within a 100m radius of the currently infested trees. Spraying the caterpillars is an option, but due to the SSSI status of Bookham Commons and the range of rare invertebrates and butterflies this approach is not suitable for Bookham.

We will be placing a large number of bird boxes to protect our trees in the future, as there is evidence that blue tits and great tits will predate the caterpillars early in the season before they become hairy.

For further information please refer to the Forestry Commission website: