Oak Processionary
Thaumetopoea processionea
The oak processionary (OPM) is a moth whose caterpillars can be found in oak forests, where they feed on oak leaves, causing significant damage. They travel in nose-to-tail processions, often arrow-headed, with a leader followed by rows of several caterpillars abreast. They are a human irritant because of their venomous setae, which can cause skin irritation and asthma. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. Source
Where it is now
No records in the last 8 weeks. It may be out of season where the observers and sensors are.
See the Oak Processionary on the live map
Arrival dates
The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.
| Region | First arrival | Last arrival | Typical peak | Areas |
|---|---|---|---|---|
| Europe | 20 July 2026 | 20 July 2026 | 27 July 2026 | 1 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.