Toxic Oak Processionary Moth Spreads Fear in Denmark, Poses Risk to Sweden

Concerns rise over the invasive oak processionary moth potentially spreading to Sweden from Denmark.

Key Points

  • • Toxic oak processionary moth discovered in Denmark, heightening concerns for Sweden.
  • • The moth's larvae can cause severe allergic reactions and skin irritation.
  • • Previously observed sporadically in Sweden, last sighting in 2014.
  • • Survival and reproduction of the moth in Sweden remain uncertain due to colder climate.

The oak processionary moth (ekprocessionspinnaren), a toxic and invasive species, has recently been discovered in Denmark, sparking concerns about its potential spread to Sweden. Observations were confirmed at a school in Odense, highlighting the risk this pest poses due to its highly irritating larvae, which can cause severe allergic reactions and skin issues in humans. This species has only been sporadically identified in Sweden, with the last sighting reported in 2014, and it has yet to establish a population in the country.

Biologists, including Peter Nilsson from the Swedish Natural History Museum, express concern about the climatic changes that may facilitate the moth's migration, noting the potential for these insects to reach Swedish territories. The larvae possess up to 700,000 toxic hairs that can trigger serious health issues, particularly in large swarms. While there are similar pests, such as the pine processionary moth already causing issues on Gotland, the oak processionary moth has gained notoriety in Southern Europe for its destructive impact.

The critical factor remains whether the conditions in Sweden allow the moths to survive and reproduce. Nilsson asserts that while isolated individuals might make it to Sweden, their establishment is uncertain due to the prevailing colder climate that poses a challenge for overwintering females. The risk of introducing this pest underscores the importance of monitoring and preventive strategies to protect Swedish ecosystems from invasive species threats.