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Ongoing construction at the Tower Shores development continues to destroy important habitat for the firefly’s strongest remaining population.


Expert Contacts

Candace Fallon, Senior Endangered Species Conservation Biologist and Public Lands Lead, The Xerces Society for Invertebrate Conservation

(954) 815-5429 | [email protected]

Tara Cornelisse, Senior Scientist, Center for Biological Diversity

(971) 717-6425 | [email protected].

BETHANY BEACH, Del.; May 15, 2019The Center for Biological Diversity and the Xerces Society for Invertebrate Conservation filed an emergency petition today seeking Endangered Species Act protection for the critically imperiled Bethany Beach firefly.

The rare firefly has been documented at only seven sites along the Delaware coast  virtually all of them smaller than a football field. The wetland area that is home to the firefly’s largest-remaining population is currently being developed.

If the U.S. Fish and Wildlife Service grants the emergency request it would be the first time Endangered Species Act protections have been awarded to one of the nation’s approximately 170 firefly species.

“Without immediate protections, the magical green flashes known to generations of children will be snuffed out forever,” said Dr. Tara Cornelisse, an entomologist who is a senior scientist at the Center. “We can’t stand by and let development, climate change and pesticides wipe out these amazing creatures, along with their wetland homes that many species depend on.”

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 recent survey.

“We’re on the brink of losing a unique piece of Delaware’s biodiversity, one that symbolizes the very habitats that have drawn so many people to this state in the first place,” said Candace Fallon, petition coauthor and senior conservation biologist at the Xerces Society. “There’s no question that this firefly urgently needs our help to prevent it from going extinct.”

Ongoing construction at the Tower Shores development 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.

When a population is lost it severely decreases connectivity between habitats, potentially reducing the number of mates available and, in turn, the number of eggs laid by females.



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 bright 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.

Firefly larvae sometimes hunt communally, and feed on slugs, snails, earthworms and other insects by injecting paralyzing fluid before consuming their prey.

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.




Read the Petition

Click here to view the full petition submitted to the U.S. Fish and Wildlife Service.


Available Photos

Images of the Bethany Beach firefly and its habitat are available for media use on the Center for Biological Diversity’s site, linked here.


The Xerces Society is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. Established in 1971, the Society is a trusted source for science-based information and advice. We collaborate with people and institutions at all levels and our work to protect pollinators encompasses all landscapes. Our team draws together experts from the fields of habitat restoration, entomology, botany 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 TwitterFacebook, and Instagram.



The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.4 million members and online activists dedicated to the protection of endangered species and wild places.