Your Land & Water June 2026
- jhansen49
- Jun 13
- 6 min read
Updated: Jun 14
What's in this issue? We take a dive into the magical world of the amazing firefly! It can go by many names but no matter what you call it they are always a delight to see flickering in the night.
Fireflies
Like ice cream cones, trips to the shore, and 4th of July fireworks, fireflies are a symbol of summer, albeit a very special one that evokes a sense of wonder. Whether as children collecting them in a jar, or as adults enchanted by their twilight illuminations, most of us have formed a positive opinion of this insect. Yet few of us know much about them.
Fireflies are a type of winged beetle in the family Lampyridae. Biologists estimate that there are 2,400+ species of firefly inhabiting the temperate and tropical zones around the world, with 270+ species in North America, and 21 to 26 species identified in New Jersey thus far. Most use bioluminescence (flashing light) to find mates and communicate with others in their species, but not all fireflies do so. Some use pheromones, a form of scent signals, and have larger antennae to pick up that chemical communication.
Flashing Light
Their light production capability is thought to have originated in larvae as a warning signal that they are distasteful to predators. This asset was then retained into adulthood by some species as a mating signal. Hence, all fireflies glow as larvae in warning to predators, yet many species are not luminescent as adults and are usually diurnal rather than nocturnal in their behavior. The latter are those species using pheromones to find mates. Regardless of these distinctions, three-quarters of all firefly species in North America are nocturnal or crepuscular (active at dusk).
Most fireflies are indeed distasteful, or even toxic, to predators because of the chemical substances in their bodies. These are lucibufagins and they are for fireflies what milkweed cardenolides are for monarch butterflies. The physical appearance of firefly species varies widely. There are differences in color, shape, size, and features such as antennae. Some species, especially lightning bugs of the genera Photinus, Photuris, and Pyractomena, have the unique courtship flash patterns with which we are most familiar. The flashes are emitted by flying males in search of females. In general, females of the genus Photinus do not fly, but do give a flash response to males of their own species. Some adult females of the genus Photuris mimic the flash pattern of other firefly species to attract males in order to eat them.
Flash signaling characteristics also differ widely by species – in duration, timing, color, number and rate of repetitions, height of flight, and direction of flight (e.g. climbing or diving), and they vary geographically within species.
Some special species are “synchronous” in their flashing. That is, they all flash at one time with correlated pauses between flashes. Photinus carolinus is a famous species that does this in the Great Smoky Mountains National Park (which spans parts of North Carolina and Tennessee) during a two-week period toward late May and early June. The synchronized flashes of Photinus carolinus take place in bursts of five to eight every few seconds or so, followed by a pause before the flashing starts again. (Access to this wonderful sight is limited and is by a lottery. Visit Recreation.gov). Scientists believe the males flash in unison so that females can confirm they’re the same species and avoid other potentially predatory firefly species. Synchronus species are found in only a handful of places throughout the world.
Habitats and Life Cycle
Fireflies favor particular habitats for mating. Most firefly species are terrestrial during their
adult stage, but some are aquatic or semi-aquatic during the larval stage, and live near rivers, wetlands and moist soils. Most firefly species thrive as larvae in rotting wood and leaf litter near the edges of ponds and streams. As they grow, they generally stay where they were hatched. Most favor fields, forests and marshes, but a few species inhabit arid areas. The preferred environment of most firefly species, however, is warm, humid, and near standing water of some type — the aforementioned ponds, streams and rivers, or even shallow depressions that are prone to retain rainfall.
Female fireflies lay their eggs on or just below the surface of the ground or, if the larvae are aquatic, on the leaves of aquatic plants, with larvae descending into the water after hatching. The larval stage lasts from many weeks to, in several species, two or more years. The larvae of most species are specialized, but they are all voracious predators and eat other larvae, snails, and slugs, feeding until the end of summer. Most fireflies hibernate through the winter as larvae, either burrowing underground or under the bark of trees. They emerge in the spring, pupate for one - or two - plus weeks and emerge as adults.
Adult diet varies among firefly species: many are predatory, while others feed on plant pollen or nectar. In most species, adults live for a few weeks into the summer. Some adults, such as the common European glow-worm (Lampyris noctiluca), have no mouth, emerging only to mate and lay eggs before dying.
Why Are Fireflies Disappearing?
Firefly populations are vanishing all over the country and the world. Although it’s not
absolutely certain, the principal causes seem to be:
Human light pollution is a decided contributing element, interfering with mating rituals and lowering reproductive success. Scientists have observed that human lights, even car headlights, interrupt firefly flash patterns. Exterior lights on homes and businesses have increased lighting at night, which makes it difficult for fireflies to signal each other during mating.
Habitat loss, mainly of leaf litter and tall grasses, reduces the food and breeding space available — halting and reversing population growth
Pesticide exposure can disrupt their metabolism and development while in egg and larval life stages, and also destroys their food
Climate change adds stress by exacerbating these above-cited threats, particularly via drought and sea level rise
Logging and pollution may also be major factors in destroying firefly habitat and their natural prey. The specialized habitats of fireflies equates to limited species’ ranges, which are easily affected by the loss of meadows, fields, and forests. Human development has reduced these locales. Along with monoculture lawns, there is less natural habitat and fewer uninterrupted locations for fireflies to live and mate.
What You Can Do
Firefly.org has excellent advice on creating habitat on your own property that will attract fireflies and on establishing a firefly sanctuary. In the meantime, here are their suggestions for helping. See their website for more details.:
Turn off outside lights at night
Let logs and litter accumulate; allow some wildness
When leaves drop in the fall, rake them if you want, but keep them in your yard as much as possible
Create natural water features in your landscape
Avoid use of pesticides, especially lawn chemicals
Use natural fertilizers
Know how much salt is necessary to de-ice sidewalks, and don’t over-do it
Don’t over-mow your lawn
Plant native trees
Do NOT introduce earthworms to your yard (they are European introductions and not native)
Talk to your neighbors to encourage them to follow your lead.
Firefly Festival
The annual Firefly Festival at Tall Pines State Preserve friendsoftallpinespreserve.org will be held on June 27, 2026. It is a great opportunity to see fireflies locally and learn more about them. You can distinguish different species by watching and timing their flash patterns, using the Massachusetts Audubon Flash Patterns Guide shown here:
Flagship Species
Fireflies are some of our most cherished and celebrated insects, dazzling us with their mesmerizing light displays, and playing important roles in human medicine, technology, and culture. They are also considered a flagship species — meaning a species whose broad appeal can help raise conservation awareness and compel public and political sympathy. Celebrated world-wide because of their beauty, fireflies don’t sting or bite, and they are not garden or crop pests. Rather, they help control pests via their feeding habits. Helping fireflies means helping other flora and fauna that depend on their shared habitats. Perhaps most critical, fireflies are a bio-indicator species. Because of their sensitivity to light pollution and water degradation, they can be observed to assess ecosystem health and function on a large scale.
So, savor the summer evening light shows, and do whatever you can to add firefly habitat in your neck of the woods.
Sources:
Fallon, Candace, Sarah Hoyle, Sara Lewis, Avalon Owens, Eric Lee-Mader, Scott Hoffman Black, and Sarina Jepson. Jewels of the Night. Guidelines for Protecting Fireflies in the United States and Canada. Xerces Society for Invertebrate Conservation. Portland, Oregon. 2019. https://www.xerces.org/sites/default/files/publications/19-049_01_Firefly%20guidelines_web_1.pdf
Firefly Atlas. The Xerces Society for Invertebrate Conservation. https://scistarter.org/firefly-atlas
Reckner, Melissa, Penguin Court Program Manager. Jewels of the Night. The Brandywine Conservancy. https://www.brandywine.org/conservancy/blog/jewels-nightAugust 19, 2020.
The Firefly Atlas. https://www.fireflyatlas.org/firefly-species/focal-species
U.S. Fish & Wildlife Service. Midwest Region Office of Communications. “Save the Fireflies.“ https://www.fws.gov/story/save-fireflies
World Population Review. “Fireflies by State 2026.” https://worldpopulationreview.com/state-rankings/fireflies-by-state
Comments