18-07-2025
Fireflies will still light up summers, despite a decline in diversity
"We are the last generation to see fireflies," says text over a July 14, 2025 post on TikTok, which gathered more than 30 million views and includes images -- some of which appear to be computer-generated -- of the little lantern bug.
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Screenshot of a TikTok post taken July 17, 2025
Similar posts expressing concern about extinction gained traction across platforms in July 2025, coinciding with the height of the insect's season in North America, where they are mainly observed between the months of May and September.
While climate stressors on certain firefly varieties exist, others have adapted well to urban habitat changes, making it unlikely that they will disappear by the end of the century, scientists say.
"In short, no, we will not be the last generation to see fireflies," Clyde Sorenson, a professor in the department of entomology and plant pathology at North Carolina State University, told AFP July 16, 2025 (archived here).
There are over 2,000 species of fireflies, found on every continent except Antarctica (archived here).
Crepuscular fireflies, such as the Common Eastern firefly, continue to proliferate in big eastern US cities, as they adapt to ambient light and may thus be more resilient to light pollution (archived here).
These are what we call habitat generalists, Sorenson explained. By nature, they are highly adaptable species (archived here).
Varying adaptability
What is at risk over the next generation, however, is firefly diversity, scientists say.
Many species that are habitat specialists -- rather than generalists -- live in ecosystems that have been significant human caused changes. They can face threats to their ecosystems due to human development, pesticide use, light pollution, climate change and natural disasters.
"Species which use coastal marshes or mangroves could be displaced as sea level rise eliminates their habitats," Sorenson said.
This is the case for the rare Bethany Beach firefly, endemic to Delaware wetlands (archived here and here).
The Bethany Beach firefly is the first of its type to be proposed for listing as threatened under the US Endangered Species Act, a federal law enacted in 1973 to protect species of fish, wildlife, and plants, as well as their habitats, from extinction.
Rising sea levels, in addition to more frequent and severe storms, threaten to degrade and eventually destroy their habitats, with the majority of the Bethany Beach firefly population likely to be lost to high-tide flooding by 2100, according to climate models (archived here and here).
"The greatest threats to the Bethany Beach firefly are the compounding impacts from climate change on habitat availability," the US Fish and Wildlife Service said in a September 30, 2024 statement (archived here.)
Three main threats
other species of fireflies have also been petitioned to be listed on the Endangered Species Act: the Florida intertidal firefly, the southwest spring firefly, the mysterious lantern firefly, and the loopy five firefly. Some are currently under review for acceptance, but none is currently listed as of July 2025.
Candace Fallon, a senior endangered species conservation biologist at the nonprofit Xerces Society for Invertebrate Conservation, told AFP that at least 18 species of fireflies in the United States are at risk of extinction (archived here and here).
"Up to a third of firefly species may be at risk once we compile enough information to conduct a thorough assessment of data deficient species," she said
Sarah Lower, a biologist at Bucknell University, told AFP that it is essential to consider "the greater likelihood of losing" local firefly populations due to human developments and changes in ecosystems (archived here).
"If the field next door becomes a paved parking lot with streetlights on all night long," and if that area "represents the last remaining population of a particular species, then that species could go extinct," she explained July 16.
Lynn Faust, an advisory consultant on firefly studies with US state and national parks, agreed (archived here).
"Fireflies have many, many challenges in today's world. Habitat destruction from development is one of the biggest," Faust, who has studied fireflies for 35 years, said July 17.
She added, however: "My personal experience is the fireflies are doing very well as long as the three things I mentioned above are not happening to their habitat."
Individuals can contribute to firefly conservation by maintaining native vegetation on their properties, limiting the use of insecticides and reducing night-time lighting as much as possible (archived here).
AFP has previously written about other claims misconstruing the impact of changes in climate and human pollution on species and ecosystems.
