Urgent Conservation Efforts to Save Europe's Glow-worms and Fireflies

An hour or so after sunset, green twinkles of possibility gleam beneath the hedgerows of Westbury-sub-Mendip in Somerset, where the last female glow-worms of the season search for mates. For nearly two decades, volunteers like Peter Bright have combed villages for these bioluminescent beetles as part of the UK glow-worm survey.

However, numbers have dramatically declined, with counts dropping from 248 in 2017 to barely 50 this year, amidst changing weather patterns. Glow-worms and fireflies consist of about 2,200 species globally, with 65 found in Europe, but across the continent, five species of glow-worm are threatened with extinction.

The common glow-worm is classified as near threatened by the International Union for Conservation of Nature. Tim Gardiner, an entomologist, notes that his 18-year survey in Essex reveals a decline of approximately 3.5% per year.

Similar trends are recognized in France, Germany, and Spain, although surveying these insects proves challenging due to their secretive nature. The alarming decline of these species is part of a broader crisis; over 40% of insect species worldwide are in decline, as highlighted by a 2019 global review.

Factors such as hotter summers threaten the slugs and snails that glow-worm larvae depend on, while habitat loss and fragmentation further exacerbate their plight. Light pollution disrupts mating displays, often luring males away from the females' glow, which poses a significant hazard.

The increase in streetlights correlates with decreased glow-worm populations in regions like Italy and Spain. To combat these challenges, some individuals have taken action; for instance, Fabio Falchi, a physics professor in Italy, reduced light pollution in his garden, resulting in successful glow-worm sightings.

Additionally, ecologist Pete Cooper has been breeding glow-worms in captivity since 2020, aiming to reintroduce them in areas where they have vanished. However, these efforts face skepticism. There are concerns that reintroduction might distract from the essential task of preserving existing populations.

Alan Stewart, an ecologist at the University of Sussex, emphasizes the need to understand the reasons for their decline before considering reintroduction. Rewilding efforts, such as those seen in Binasco, Italy, where volunteers revitalized land, have led to the return of fireflies after years of absence.

This demonstrates the potential for habitat management to boost insect populations, as seen in areas where corridors between habitats have been restored. Local initiatives, like glow-worm walks, have gained popularity, fostering community connections to nature.

As Amanda Bennett, a participant in a glow-worm walk, expresses wonder at seeing a glow-worm for the first time, it highlights how these insects can serve as a gateway for people to engage with the natural world.

While there is hope for conservation, ongoing efforts are critical to reversing the decline of glow-worms and fireflies across Europe.