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View of an interdunal swale at Assateague Island, showcasing a shallow, wetland area nestled between a sand dune. The swale is filled with shallow water and surrounded by tall grass with a sand dune rising in the background under a clear blue sky.
Interdunal swale at Assateague Island National Seashore, Maryland
Xerces Society/Candace Fallon
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Rare Fireflies Found at Assateague Island National Seashore

NPF Supports Efforts to Conserve Rare Firefly Species Habitat at Assateague Island National Seashore
By Ava Garibay

Fireflies are among the few land animals that can produce light through a chemical reaction in their bodies, known as bioluminescence. Remarkably, this process generates light without producing heat, making fireflies exceptionally efficient light producers! Different firefly species have unique light patterns to help potential mates identify each other. Photuris bethaniensis, more commonly known as the Bethany Beach firefly, is a rare firefly species characterized by two bright green flashes given off by males in search of a female mate. The firefly was believed to be native to Bethany Beach, Delaware until a confirmed sighting nearly 30 miles away at Assateague Island National Seashore, Maryland.

Photuris bethaniensis (Xerces Society/Candace Fallon)

The discovery sparked a collaboration between the National Park Service and Delaware State University, with the help of other key project partners — U.S. Fish and Wildlife Service, Delaware Department of Natural Resources and Environmental Control, Maryland Department of Natural Resources, and The Xerces Society. With funding from the National Park Foundation, this initiative aims to study the firefly’s habitat and inform protection strategies of the species for many summers to come.

The study will consist of conducting comprehensive surveys, beginning this summer, to identify the presence and abundance of Bethany Beach fireflies and their habitat requirements across Assateague Island. The goal is to fill an information deficit around this firefly species, with the potential to apply these findings to Delaware seashores as well.

Firefly surveyors (Xerces Society/Candace Fallon)

While the firefly is considered critically endangered by the International Union for Conservation of Nature, its petition to be listed as endangered under the Endangered Species Act has been under review since 2019. The Endangered Species Act provides extra protection to vulnerable species and has proven to be highly successful, credited with saving 99% of listed species from extinction. Because petitions require thorough scientific evaluation and review before species are officially listed, a lack of scientific research and findings is preventing the Bethany Beach firefly from receiving critical protection.

In addition to aiding its petition to be listed on the Endangered Species Act, the survey will be critical in understanding the Bethany Beach firefly’s habitat needs. While scientists have some idea of their habitat, this research will be key to better understanding where the Bethany Beach fireflies call home. Understanding suitable habitat requirements will be essential for developing protection and park management strategies to protect the Bethany Beach firefly and other rare firefly species.

Helping Fireflies at Home

You don’t have to be a firefly expert to help protect the Bethany Beach firefly and your own backyard fireflies. Because artificial lights interfere with firefly mating and communication signals, turning off unnecessary outdoor lights at night will help fireflies reproduce and sustain their populations. Additionally, you can make your backyard a haven for fireflies by avoiding pesticide use and planting native plants and grasses. These simple actions can help support the ongoing efforts like the Bethany Beach firefly study to protect fireflies and their habitat.

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