Oak Processionary Moth Finding 2023

On 12th June 2023 the Department announced a finding of Thaumetopoea processionea, commonly known as the Oak Processionary Moth (OPM) in Ireland. Oak Processionary Moth caterpillars were found on four Oak trees in a Dublin housing estate. The nests and four trees have been destroyed.

Ireland has a Protected Zone status under the EU Plant Health legislation for this pest. A Protected Zone is an area of the EU which is free from a harmful organism. DAFM have commenced an investigation into this infestation. Surveying for this pest around the infected site has commenced and an intensive survey campaign using trapping methods and visual examinations of oak trees will continue over the coming weeks and months.

The caterpillars (larvae) of this moth are mainly associated with feeding on the foliage of Oak (Quercus) tree species. However, when there are limited oak trees available, larvae have been observed to feed on other tree species (Acacia, Birch, Hornbeam, Hawthorn, Hazel and Beech) but it is uncertain whether they can survive on these species and complete their lifecycle development to adults. The caterpillars (larvae) feed on leaves and can cause severe defoliation leaving trees weakened and open to secondary infections from other pest and diseases.

In addition, this moth also poses a potential risk for human health and animal health, as the body of the caterpillar is adorned with numerous irritating hairs. Contact with the hairs can provoke allergic reactions which manifest as skin rashes, conjunctivitis and respiratory problems such as pharyngitis and asthma.

Do Not:

• touch or approach nests or caterpillars

• let children touch or approach nests or caterpillars

• let animals touch or approach nests or caterpillars

• try removing nests or caterpillars yourself

Do:

• warn children not to touch or approach the nests or caterpillars

• seek medical advice if you think you or someone you care for has been seriously affected

• see a vet if you think your pet or livestock has been seriously affected

Oak Processionary Moth Factsheet

The Department’s Plant Science Division’s Pest Risk Analysis Unit (PRAU) have developed summary factsheets on a range of plant pests including a factsheet on Oak Processionary Moth - Item was unpublished or removed

Oak Processionary Moth Trader Notice

Professional Operators have been informed of the finding through a trader notice issued on 12th June 2023 - Trader Notice No.4 of 2023 Finding of Thaumetopoea processionea (Oak Processionary Moth) in Ireland

Suspected Sighting?

Suspected sightings should be treated with extreme caution and notified immediately to DAFM with your contact details and geolocation of the sighting by emailing plantandpests@agriculture.gov.ie or by telephone 01-5058885.

Suspected sightings in Ireland should be treated with extreme caution and notified immediately to DAFM with your contact details and geolocation of the sighting by emailing plantandpests@agriculture.gov.ie or by telephone 01-5058885.

For any queries on Oak Processionary Moth or general plant health queries, please email plantandpests@agriculture.gov.ie.

Additional information available at the links below:

• General plant health information: Item was unpublished or removed
• 2023 finding of Oak Processionary Moth: gov - Oak Processionary Moth Finding 2023 (www.gov.ie)
• DAFM’s Oak Processionary Moth Factsheet: Item was unpublished or removed
• National Biodiversity Data Centre: ID-Guide_Oak-processionary-moth_NIEA-NBDC_August2023.pdf (invasives.ie)