There are more than 2,000 species of fireflies, and scientists are sounding the alarm that some of these species are on the brink of extinction. Research published in BioScience indicates that habitat loss, light pollution and pesticides are threatening these delightful insects.
According to Tufts University biology professor Sara Lewis, the study’s lead author, “If people want fireflies around in the future, we need to look at this seriously. Fireflies are incredibly attractive insects, perhaps the most beloved of all insects, because they are so conspicuous, so magical.”
Habitat loss is the main culprit disrupting the environmental conditions and cues conducive to firefly development and lifecycle completion. One example cited was the Malaysian firefly species Pteroptyx tener, which needs particular mangroves and plants to breed appropriately, but their mangrove swamp habitats have been displaced by aquaculture farms and palm oil plantations.
The second issue leaving fireflies vulnerable is light pollution. As CNN reported, light pollution can arise from “streetlights and commercial signs and skyglow, a more diffuse illumination that spreads beyond urban centers and can be brighter than a full moon.” Artificial lights can interfere with firefly courtship. Male fireflies flash particular bioluminescent patterns to attract females, who must flash responses in return. Unfortunately, artificial lights can mimic and thus confuse the signals. Or, worse yet, light pollution can be too bright for the fireflies to emit and properly recognize their ritual signals for mating to be initiated or completed.
Thirdly, pesticides have been a significant driving factor in the decline of firefly populations. The Center for Biological Diversity has documented that “Systemic pesticides like neonicotinoids that get into the soil and water harm firefly larvae and their prey. Also, because fireflies are generally found in wetland habitats, they are threatened by insecticide spraying targeting mosquitoes.” As a result, the larvae either starve or have developmental anomalies that prevent population growth.
Public outcries by the International Union for Conservation of Nature (IUCN)’s Firefly Specialist Group as well as the Fireflyers International Network have raised some awareness about the dwindling firefly populations. Yet, as stated by the Center for Biological Diversity, “There are at least 125 species of fireflies in the United States, but despite the many threats they face, none are protected by the Endangered Species Act.”
To protect these luminous insects that have long captivated the imagination with their fairytale-like lights, much work still needs to be done, especially given the U.K. Wildlife Trusts’ similar report on the ‘quiet apocalypse’ taking place now, wherein 41% of global insect species face extinction.
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