Pest or disease?
Pest

Latin name:
Thaumetopoea pityocampa

Host trees:
Pine trees 

Present in the UK?
No

Tree Alert required?
Yes

Pine processionary moth, or PPM, is a pest of pine trees. It is native to southern Europe, North Africa and the Middle East. It has been extending its range northwards and is now established in Hungary, Switzerland and in the Paris region of France. There have been no established populations in the UK although single moths and in one instance, a single population was found in Southern England and subsequently eradicated. 

PPM belongs to the same genus as our other priority pest, Oak processionary moth (which is present in the UK). The PPM caterpillars feed on foliage of pine trees and their hairs can irritate our skin, therefore it is important not to touch or approach the caterpillars or their nests. 

PPM caterpillars feed on pine needles causing defoliation. They are identifiable by their distinctive movement; they move from their nest to feeding areas in processions one caterpillar wide. Their nests are found typically towards the end of branches, either on the branch itself or within the needles. The caterpillars and nests are seen in winter and early spring, unlike oak processionary moth caterpillars which are most active in late-spring and summer. The adult PPM moth is rarely seen and difficult to identify. 

For more information on Pine processionary moth, see the resources below. 

This page was updated 04/2025