Bad at Goodbyes

Rough Transcript

Intro 00:05

Welcome to Bad at Goodbyes.

On today’s show we consider the Bethany Beach Firefly.

Species Information 02:05

The Bethany Beach Firefly is a critically endangered insect native to the eastern coast of North America, specifically the US states of Delaware, Maryland, and Virginia.

 

Its scientific name is Photuris bethaniensis and it was first described in 1953.

 

The Bethany Beach Firefly is a small firefly, with an elongated flat body, measuring roughly one third of an inch in length and an eighth of an inch in width. Entomologists divide insect anatomy into 3 sections, the head, the thorax, and the abdomen. 

 

The firefly’s head has two large, compound eyes adapted for the dim light of dusk and of nighttime. BEtween the eyes are a pair of segmented antennae, covered in sense receptors. They have mandibulate mouthparts, made up of the labrum (like an upper lip holding three teeth), the mandibles (which are like sharp horizontal pincers), the Maxillae (which are tiny palps (like antenna but for taste sensing)), and the labium which is the like lower lip.

 

As larvae, they are primarily carnivorous, the mandibles are well-developed for capturing and consuming prey. However, in adult Bethany Beach Firefly, the mandibles are reduced in size as their diet is not focused on solid food. Many adult fireflies, including the Bethany Beach, consume solid food sparingly or even not at all. So instead, as adults, their mouthparts are mainly used for drinking nectar and water.

 

Next, the thorax is the middle section of the firefly’s body. A hardened structure called the pronotum covers the top of the thorax, protecting the fireflies internal organs. The Bethany Beach Firefly has a distinctive dark brown or black mark on their pronotum.

 

Three pairs of long jointed legs extend from the thorax, that enable the firefly to walk, climb, and grasp onto vegetation. They have two pairs of wings: the hardened forewings, called elytra, are a protective cover for the delicate, membranous hindwings that are used for flight. The elytra are a reddish brown tan, that are stripped with darker brown; the hindwings, the flight wings, are translucent.

 

The abdomen is the large posterior section of the firefly’s body. It holds the digestive and reproductive organs, as well as spiracles, these are tiny openings, connected to tube-like structures, that are adapted for respiration, for breathing. The firefly intakes oxygen through the spiracles, that is circulated to its internal organs and then expelled as carbon dioxide.

 

The abdomen also holds the firefly’s bioluminescent organ, the parts that light up, fittingly and gorgeously called a lantern. So the simplified version is that bioluminescence is a chemical reaction that in the presence of oxygen, releases energy as light. The firefly synthesizes a kind of simple energy storage molecule called luciferin, that in the presence of oxygen and the enzyme luciferase releases energy in the form of light. So, when a firefly illuminates, its nervous system directs oxygen into the lantern. There, the luciferase binds to luciferin catalyzing a reaction which releases excess energy as photons, tiny packets of light.

 

Firefly have remarkable control over this process, by regulating oxygen flow they can create specific flashing patterns used for communication and attracting mates. In the case of the Bethany Beach Firefly, the males emit a bright, greenish double flash, with two quick bursts of light close together, typically repeated every few seconds. This double flash pattern is part of their courtship. The males, while in flight, will emit their double flashes to attract females. The females, perched on nearby vegetation, will respond with a single flash if they are receptive to mating, signaling their location and willingness.

 

During copulation, which occurs on vegetation or the ground (like not in flight) the male uses its sex organ to transfer a spermatophore into the female’s reproductive opening and into its reproductive tract. The spermatophore contains sperm cells, and includes additional nutrients to provide the female with energy and resources for egg production. The released sperm travel to the female’s spermatheca, a storage organ, which allows her to control the fertilization over time; she can lay fertilized eggs at a later date, and lay multiple distinct clutches, even after a single mating.

 

Eggs are laid in moist soil, leaf litter, or rotting wood and hatch after about 2-3 weeks.

 

The lifecycle of the firefly is unexpected, or at least I did not really realize the arc of their lives. Here’s what it looks like: the eggs hatch into a larval stage. Larvae are small, no wings yet, with a long segmented oval-shaped body, and they glow, emitting a little bioluminescence that scientists believe is an adaptation to ward off predators. Larvae are dietary generalists, consuming soft-bodied invertebrates like snails and worms, and plant material like berries. As they grow over a two year period, they repeatedly molt to shed their exoskeleton, getting larger and larger, and then in the winter of their second year, they burrow into the soil to pupate. Roughly a month later in the beginning of spring, they undergo metamorphosis, breaking down their pupa body, triggering biochemical reactions that transform them into an adult firefly.

 

This wildly transformed now glowing, now flying, adult firefly, has roughly 8 weeks to reproduce before it dies. Its short adult life is primarily focused on mating.

 

So let’s lay this approximately 2 and half year lifespan out. 2 weeks as an egg; 2 years as larvae, a month as a metamorphosing pupa, and just 2 months as an adult. This small sliver of their life as the thing we know, summer lantern, soon extinguished.

————

In the dream, four poems by Basho:

At sun down / the fragile light / of a firefly.

A fool in the dark / hunting fireflies / grabs a bramble.

Watching fireflies - / Our boatman is drunk / his boat is unsteady.

Blade of grass / a firefly lands / takes off again.

 

And one by Nobuko Katsura

firefly night / wearing my kimono loosely / to meet him

 

And one by me:

Our daughter dancing / oh to remember that now / summer firefly

 

In the dream.

————

The Bethany Beach Firefly is native to the Eastern Coast of North America, specifically a chain of barrier islands in Delaware, Maryland, and Virginia, with firefly populations found in roughly 35 distinct, not-contiguous sites across a roughly 150 mile span of coastline.

 

The Bethany Beach Firefly is restricted to interdunal swales. Restricted means that we believe that the firefly can only survive in this specific habitat. And interdunal swales are this rare unusual ecosystem, that arises when rain and freshwater from the groundwater table collect in the small valleys between coastal sand dunes. These are a kind of constrained freshwater marshland, bordered by dune slopes near the sea. The swales grow dense vegetation: grasses, sedges, ferns, and shrubs like bayberry and groundsel tree and host thriving populations of small invertebrate.

 

This is a super specific and dynamic ecosystem, reshaped by changes in water level, wind and sand drift. All populations of the Bethany Beach Firefly are found within 1500 ft of the ocean, inhabiting the freshwater foliage that thrives in the interdunal swales.

 

This Mid-Atlantic coastal region has a subtropical climate, with hot and humid summers and cooler winters. Summer high temperatures average in the mid-80s°F and winter lows near freezing. Annual rainfall is approximately 42 inches.

 

The Bethany Beach Firefly shares its home with:

Eastern Painted Turtle, Needlepod Rush, Piping Plovers, Common Reed, Raccoon, Bayberry, American Bullfrog, Sandpiper, Raspberry, Rabbit, River Otter, Silver Grass, Green Frog, Salt Marsh Hay, Squirrel, Gull, Osprey, Sanderling, Northern Water Snake, Three-Square Needlerush, and many, many more.

 

The Bethany Beach Firefly faces a range of threats, primarily from human activity that encroaches upon and degrades their specialized habitat.

 

The rapid development of coastal areas for residential and commercial purposes has led to the direct destruction and fragmentation of the firefly’s interdunal swale habitat.

 

We have two recent specific examples of this: Observational surveys between 1998 and 1999 found a population of the Bethany Beach Firefly thriving in an interdunal swale on private land roughly 3 miles north of Bethany Beach. Following the construction of new housing on the location, followup surveys from 2019-2023 found no firefly on the site.

 

Even more insidious: In 2019, developer Louis Capano III exploited a loophole in Delaware environmental laws to build a roadway and new houses on a Bethany Beach Firefly swale habitat. This designated wetland is protected by state law from being filled in for new construction. So to get around that prohibition Capano builds a raised roadway on pilings, technically not filling in the land, but of course the road on stilts blocks sunlight to all of the plants beneath and the habitat is destroyed. Recent surveys found no Bethany Beach Firefly at the site. Capano made upwards of $10 million in real estate profits from this “technically legal” build.

 

Construction of houses, roads, and infrastructure not only eliminates swales directly but also disrupts the ecosystems hydrological balance. The increasing demand for freshwater in coastal communities leads to increased groundwater pumping, lowering the water table, drying out the interdunal swales.

 

Relatedly, increased residential development has led to increased pesticide use, particularly those used for mosquito control, which poses a direct threat to the fireflies. These chemicals end up in the swales through runoff or drift, contaminating the soil and poisons both the fireflies and their larvea’s prey.

 

Another result of coastal development is light pollution, so artificial lights from homes, roads, and businesses disrupt the firefly’s nocturnal mating behavior. The fireflies rely on their bioluminescent signals for courtship, and excessive light interferes with their ability to find and attract mates. 

 

And lastly, human induced climate change is causing sea levels to rise and increasing the frequency and intensity of offshore storms. This results in more frequent and severe saltwater flooding of the swales, which is degrading and will ultimately destroy the firefly’s habitat. Using an intermediate climate change forecasting model, so in between worst case and best case, 93% of Bethany Beach Firefly’s habitat is expected to be degraded or destroyed by the end of this century.

 

Unfortunately almost no protections are in place for the Bethany Beach Firefly or its habitat. In October 2024, the US Fish & Wildlife Service accepted a proposal to include the firefly in the federal Endangered Species Act. The public commenting period of that proposal ended in December 2024. And yet, as of June 11, 2025, protection of the Bethany Beach Firefly has not been codified into law. I double-checked the National Archives Code of Federal Regulations, this is Title 50 Chapter 1 Subchapter B Part 17 Subpart D § 17.47, and the Bethany Beach Firefly is still not listed.

 

Fortunately, most of the current firefly population inhabit state protected land, like Cape Henlopen State Park, Delaware Seashore State Park, Fenwick Island State Park, False Cape State Park.

 

And regular citizens can help protect the Bethany Beach Firefly and participate in conservation of even your own backyard fireflies. A primary threat to all firefly is artificial light, which disrupts bioluminescent mating and communication signals, impeding successful reproduction. Simplifying turning off exterior lighting after dusk, helps.

 

The Bethany Beach Firefly has been considered critically endangered on the IUCN Red List since 2021 and their population is currently in decline.

 

Recent counts estimate less than 1800 Bethany Beach Firefly remain in the wild.

Citations 31:04

Information for today’s show on the Bethany Beach Firefly was compiled from:

 

Annual Review of Cell and Developmental Biology. Volume 14, Nov 1998 pp 197-230. Thérèse Wilson, and J. Woodland Hastings. “Bioluminescence”. –  https://doi.org/10.1146/annurev.cellbio.14.1.197 

 

The Coleopterists Bulletin v.58 no.3, pp 349-353, September 2000. Christopher M. Heckscher and Charles R. Bartlett. “Rediscovery and Habitat Associations of Photuris Bethaniensis McDermott (Coleoptera: Lampyridae)”. – https://doi.org/10.1649/622 

 

Delaware News Journal June 21, 2019. Maddy Lauria. “Rare Bethany firefly threatened by new beach homes”. – https://www.delmarvanow.com/story/news/local/delaware/2019/06/21/new-beach-development-could-help-kill-off-rare-bethany-firefly/1508724001/ 

 

Insects vol. 15, no. 1: 71. Lewis, Sara M., Wan F. A. Jusoh, Anna C. Walker, Candace E. Fallon, Richard Joyce, and Vor Yiu. 2024. “Illuminating Firefly Diversity: Trends, Threats and Conservation Strategies”. – https://doi.org/10.3390/insects15010071 

 

The IUCN Red List of Threatened Species 2021: e.T164045981A166771578. Heckscher, C., Walker, A. & Fallon, C. 2021. “Photuris bethaniensis”. – https://dx.doi.org/10.2305/IUCN.UK.2021-1.RLTS.T164045981A166771578.en

 

National Archives Code of Federal Regulations – https://www.ecfr.gov/current/title-50/chapter-I/subchapter-B/part-17/subpart-D/section-17.47 

 

PLOS One. November 17, 2021. Candace E. Fallon , Anna C. Walker, Sara Lewis, Joseph Cicero, Lynn Faust, Christopher M. Heckscher, Cisteil X. Pérez-Hernández, Ben Pfeiffer, Sarina Jepsen. “Evaluating firefly extinction risk: Initial red list assessments for North America”. – https://doi.org/10.1371/journal.pone.0259379 

 

Proceedings of the United States National Museum. Vol 103 (3314):35–37. McDermott, Frank A. 1953. “Photuris bethaniensis, a New Lampyrid Firefly”. – https://doi.org/10.5479/si.00963801.3314.35 

 

Sierra Club Delaware Chapter – https://www.sierraclub.org/Bethany-Firefly 

 

University of Minnesota Department of Entomology – https://entomology.umn.edu/bethany-beach-firefly 

 

US Fish and Wildlife Service – https://www.fws.gov/species/bethany-beach-firefly-photuris-bethaniensis 

US Fish and Wildlife Service Species Status Assessment Report For the Bethany Beach Firefly February 2024 – https://www.fws.gov/node/5231946

 

The Xerces Society for Invertebrate Conservation. 2024. 22 pp. Fallon, C. and R. Joyce. “Firefly Species Fact Sheet: Bethany Beach Firefly, Photuris bethaniensis.” – https://www.fireflyatlas.org/threatened-species-fact-sheets/ 

 

For more information about the conservation and protection of the Bethany Beach Firefly please visit the Xerces Society for Invertebrate Conservation at http://xerces.org.

Music 33:28

Pledge 42:29

I honor the lifeforce of the Bethany Beach Firefly. I will commit its name to my record. I am grateful to have shared time on our planet with this being. I lament the ways in which I and my species have harmed and diminished this species. I grieve.

 

And so, in the name of the Bethany Beach Firefly I pledge to reduce my consumption. And my carbon footprint. And curb my wastefulness. I pledge to acknowledge and attempt to address the costs of my actions and inactions. And I pledge to resist the harm of plant and animal kin and their habitat, by individuals, corporations, and governments.

 

I forever pledge my song to the witness and memory of all life, to a broad celebration of biodiversity, and to the total liberation of all beings.