Why are Fireflies Disappearing?
- Aldrin V. Gomes
- 6 hours ago
- 3 min read
Updated: 2 hours ago
Fireflies, known for their bioluminescent glow that beautifully lights up forests, fields, and dark marshes across the world, have been disappearing at an alarming rate. Many populations are noticing the rapid disappearance of nature's lights, with some reporting drastic drops in sightings. In India, one of the most firefly-rich countries, citizen reports indicate a 76% decrease in firefly sightings over just a single year (Paul, 2025). Further research suggests that roughly one-fifth of firefly species are endangered, with a 2021 study stating that one in three North American firefly species assessed may be at risk of extinction. For the first time, fireflies are being considered for the Red List to identify at-risk species, highlighting the urgent need to protect them (Fallon et al., 2025).
fireflies are vital organisms
More than just nature's nightlights, fireflies act as a keystone species that are vital to maintaining ecological balance by feeding on worms, other insects, and acting as crucial pollinators. Not only is the luminescence of fireflies ecologically significant, but it is also significant for scientific and medical advancements, as it can be used in imaging to identify cancer cells and drug targets (Dickinson, 2018). Therefore, when fireflies, as essential pollinators and predators of worms and pests, are showing signs of decline, what does that say about the health of their environments, and why is this happening?
Two leading causes of this problem have been identified: habitat loss and light pollution. Fireflies have a unique reproductive cycle in which they remain in the larval stage for 1-3 years before pupating, making it crucial for their development that the larvae buried in soil remain undisturbed (Paul, 2025). However, with increasing soil disturbance from pesticides, construction, habitat destruction, and more, this has dramatically increased the endangerment of fireflies.
Fireflies also use their flashing abdomen as a mating dance, continuously flashing throughout the night so that male fireflies can find them, but artificial lights are increasingly disrupting this process. Now, 22.5% of Earth's habitable land surface is covered in artificial lights, with brightness increasing by around 50% over the last 25 years (Owens et al., 2022, Kyba et al, 2017, Falchi et al, 2016) (need to check and add the new references). Being constantly on the lookout for signaling, fireflies are confused by artificial lights, which disrupt or even halt mating and harm their highly sensitive compound eyes.
Some try to combat the artificial light by increasing the intensity and duration of their glow, draining their energy, and overloading their metabolic processes commonly used for growing and foraging (Shen et al., 2025). Light pollution not only affects their ability to mate but also shrinks their habitat as they migrate away from artificial light sources to find dark spaces where they can thrive (Paul, 2025).
Conservation Efforts
Furthermore, while firefly festivals, which were used to increase awareness, have become more popular over the years, the increased number of tourists, disruptions, and flash photography have been shown to cause more harm to these insect communities than good (Paul, 2025). However, there are alternative actions we can take to support fireflies worldwide, which are crucial to maintaining ecological stability, pollinating our flowers, and bringing beautiful natural light and luminescence to nature. For example, light-polluted regions can work to reduce artificial lighting, specifically during the nighttime and mating season, in heavily populated areas with fireflies. There can also be greater efforts to avoid disrupting the ground that firefly larvae need to properly complete their full, healthy life cycle, by minimizing pesticide and herbicide use or finding alternatives.
On a more positive note, there have been more sightings of fireflies in recent years due to warmer temperatures and favorable climate conditions, but these sightings have been mainly in rural areas where light pollution and habitat destruction are less significant threats. These fireflies can be seen migrating from developed regions into more rural areas where they can thrive. While recent claims spreading across social media that we are the last generation to see fireflies may not be true, fireflies are facing increasing threats, and their declining numbers could be a warning sign to take preventive measures.
Written by Rain Kim and edited by Aldrin Gomes, PhD
References
Dickinson, J. Lampyrid 2018, 8: 03–04
Falchi, F., et al. 2016. The new world atlas of artificial night sky brightness. Science Advances, 2(6), e1600377. https://www.science.org/doi/10.1126/sciadv.1600377
Fallon CE, Walker AC, Lewis S, Cicero J, Faust L, et al. 2021. Evaluating firefly extinction risk: Initial red list assessments for North America. PLOS ONE 16(11): e0259379. https://doi.org/10.1371/journal.pone.0259379
Kyba, C. C. M., et al. 2017. Artificially lit surface of Earth at night increasing in radiance and extent. Science Advances, 3(11), e1701528. https://www.science.org/doi/10.1126/sciadv.1701528
Owens, A.C.S., et al. "Behavioral responses of bioluminescent fireflies to artificial light at night." Frontiers, 26 September 2022, https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2022.946640/full
Paul, A., The Dimming of the Night: A Comprehensive Analysis of Firefly Extinction and Conservation, with a Global and Indian Perspective. SSRN. 2025. http://dx.doi.org/10.2139/ssrn.5599499
Shen, M., Qing, Z., Lin, S. 2023. The Impact of Environment Situation on Fireflies and the Contribution of Fireflies on Environment Situation. Theoretical and Natural Science. 4. 391-396. https://www.researchgate.net/publication/371186842_The_Impact_of_Environment_Situation_on_Fireflies_and_the_Contribution_of_Fireflies_on_Environment_Situation
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