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U.S. Fish and Wildlife Service moves one step closer to protecting first firefly species.


Expert Contact:

Candace Fallon, Conservation Biologist and Firefly Lead, Xerces Society for Invertebrate Conservation

(954) 815-5429  |  [email protected] 

BETHANY BEACH, Del., December 19, 2019Responding to an emergency petition filed by the Xerces Society for Invertebrate Conservation and the Center for Biological Diversity, today the U.S. Fish and Wildlife Service announced a positive 90-day finding for the Bethany Beach firefly and is initiating a full status review of the species.

This critically imperiled species, which is known only from Delaware, has been documented at only seven sites along the state’s Atlantic coast. Ongoing residential development in a wetland area known to host the Bethany Beach firefly’s largest remaining population poses a significant threat to this species.

This is the first firefly in the United States to be considered for Endangered Species Act protection by the U.S. Fish and Wildlife Service.

“Protection for this firefly can’t come soon enough,” said Candace Fallon, petition coauthor and senior conservation biologist at the Xerces Society. “We’re on the brink of losing a unique piece of Delaware’s heritage.”

The Bethany Beach firefly has been pushed to the brink of extinction by urbanization, light pollution, habitat fragmentation, pesticides and climate change-induced sea-level rise and storm surges.

The firefly has nearly disappeared from three of its seven remaining sites. Six of the firefly’s seven remaining populations are in state parks, but only a single firefly was found at two of those sites during the most recently published survey.

Ongoing construction at a Bethany Beach development site continues to destroy important habitat for the firefly’s strongest remaining population. Loss of that population would greatly lessen the species’ chances of survival because these fireflies are weak fliers and rarely disperse beyond the habitat in which they were born.



The Bethany Beach firefly is only found within 1,500 feet of the shore, making its habitat extremely vulnerable to rising sea levels and increases in storm surges caused by climate change. The combination of higher water levels near housing developments and popular recreation areas has resulted in frequent spraying of pesticides to control mosquitoes with chemicals toxic to fireflies.

The Bethany Beach firefly flies at full darkness, so that females can spot and blink in response to a male’s double green flash. After mating the females will continue to flash, but this time mimicking other firefly species to lure in males to eat them and gain their valuable protective toxins. These mating signals can be disrupted by habitat changes, and light pollution can change their courtship behavior and mating success.

Fireflies live on every continent except Antarctica. But just as in Delaware, many of their populations are threatened by habitat destruction, light pollution, climate change, and pesticides.




Federal Register announcement from U.S. Fish and Wildlife Service: Endangered and Threatened Species: 90-Day Findings for Two Species (Scheduled Publication Date: 12/19/2019)

Petition for the Emergency Listing of the Bethany Beach Firefly (Photuris bethaniensis)

Species profile of the Bethany Beach firefly

On the Xerces blog: Taking a Stand for Firefly Species Facing Extinction

Firefly conservation guidelines: Conserving the Jewels of the Night

Xerces Society’s firefly conservation campaign


About the Xerces Society

The Xerces Society is a nonprofit organization that protects the natural world by conserving invertebrates and their habitat. Established in 1971, the Society is a trusted source for science-based information and advice and plays a leading role in promoting the conservation of pollinators and many other invertebrates. We collaborate with people and institutions at all levels and our work to protect bees, butterflies, and other pollinators encompasses all landscapes. Our team draws together experts from the fields of habitat restoration, entomology, plant ecology, education, farming, and conservation biology with a single passion: Protecting the life that sustains us.

To learn more about our work, please visit or follow us @xercessociety on Twitter, Facebook or Instagram.



The Xerces Society has photographs of this firefly’s interdunal swale habitat and threats facing it available for use by media outlets related to this story. Contact Matthew Shepherd ([email protected]; (503) 807-1577) at the Xerces Society.