Distinguished from similar species by pale basal area of the forewing, and central crescent mark, which is small and faint. The Oak Processionary flies at night and can be found at light. The male is migratory but the female is much more sedentary.
Overwinters as an egg which can be found in batches on twigs. The caterpillars hatch in April and can be found until late June in communal silk nests, usually quite high up, on or often underneath a major branch, but sometimes lower down.
Flight Season
Flies from late July through to mid-September in one generation.
Size and Family
- Family – Notodontidae
- Medium Sized
- Wingspan Range – 25-35mm
Conservation Status
- UK BAP: Not listed
- Established immigrant/accidental reintroduction
Caterpillar Food Plants
The caterpillars feed on the leaves of a variety of native and planted Oak (Quercus). Prefers mature trees but can be found on bushes at least 2 metres high.
Habitat
Can be found in broadleaved woodland, parks, gardens and other open spaces with isolated trees and scrub.
Distribution
- Countries – England and the Channel Islands
- Established vagrant and resident

Oak Processionary - Stuart Read
Oak Processionary
Stuart Read

Oak Processionary - Ben Sale
Oak Processionary
Ben Sale

Oak Processionary - Vlad Proklov
Oak Processionary
Vlad Proklov

Oak Processionary - Vlad Proklov
Oak Processionary
Vlad Proklov

Oak Processionary - Vlad Proklov
Oak Processionary
Vlad Proklov

Oak Processionary - Vlad Proklov
Oak Processionary
Vlad Proklov

Oak Processionary - Koen Thonissen
Oak Processionary
Koen Thonissen

Oak Processionary - Vlad Proklov
Oak Processionary
Vlad Proklov

Oak Processionary - Dave Shenton
Oak Processionary
Dave Shenton

Oak Processionary (caterpillars) - Koen Thonissen
Oak Processionary (caterpillars)
Koen Thonissen

Oak Processionary (larval nest) - Vlad Proklov
Oak Processionary (larval nest)
Vlad Proklov