Fireflies – nature’s fireworks display

This summer is already different than other summers. Camps are closed, beaches are open but there are no lifeguards, Old Home Days and other seasonal festivals are postponed and fourth of July firework shows are canceled. This is a lot to take in and we all feel like we are missing out on things.

But it is also an opportunity, a chance to find the silver linings of a quieter less busy way. More people are planting gardens and out hiking, paddling, biking and walking. I’ve seen more family picnics than ever before and kids are out flying kites, jumping rope, riding bikes and scooters and blowing bubbles.

Slowing down does have its advantages. It gives us all a chance to try the old things that use to entertain us when life was less busy and simpler.

One of these simple joys of this season has to be fireflies. Do you remember – a big meadow in the warm summer evenings, the darkness glittering with the fairy-tale light of a thousand fireflies. Maybe this year, instead of fireworks, we can look to meadows glittering with the flash and sparkle of these luminous bugs. It might not be as loud or colorful as fireworks but it is perhaps even more magical to witness a field filled with the twinkling of lightening bugs.

Think about it – it’s a tiny beetle, producing its own light in the middle of all the darkness. Fireflies are beetles that all belong to the Lampyridae family and in North America there are over 150 species of these beetles. Not all the members of this family produce light but the ones that do add a special bit of glimmer to our summer evenings.

The firefly’s glow is produced by a chemical reaction in the beetle’s lower abdomen. This ability of a living being to produce light through a chemical reaction is known as bioluminescence. Most organisms that can do this are found in marine habitats, like jellyfish and squid. Fireflies, glow-worms and certain fungi are among the rare terrestrial beings that have this unique ability. A firefly’s light works a bit like a glow-stick. It produces light that is cool to the touch. The chemicals involved in this reaction include calcium, adenosine triphosphate (ATP), a naturally occurring chemical called luciferin, and a special enzyme found inside the firefly’s light organ known as luciferase. When oxygen is added to this combination of ingredients, it activates a reaction that produces light.

Long ago people would gather fireflies to light up their summer nights. As it turns out, firefly light is highly efficient. Almost all of the energy produced in the chemical reaction is released as light. Recent scientific discoveries have turned the light on to other ways the chemistry of fireflies are beneficial to humans, including medical advances, biotechnology and public health. In the 1960’s scientists developed a food safety test using the chemical luciferin and the enzyme luciferase. This test, which is highly efficient at detecting food spoilage, is still used today, but is now being done with synthetic versions of these two firefly ingredients.

Fireflies flash to attract mates, defend territory and communicate. Different species of fireflies have specific blinking patterns. The females typically rest in the vegetation, while the male flies around flashing their particular pattern. When the female sees a male of her own species, she responds by displaying the same pattern back to him. He will then fly to her and they will mate.

Fireflies would seem like easy prey for nocturnal predators, easy to spot as a bright bit of light in a dark sky. But it turns out that fireflies’ release toxic droplets of blood when attacked by predators. Birds, toads, spiders and others soon learn that eating a firefly might be easy but it isn’t tasty.

However, one predator in particular isn’t dissuaded by the firefly’s toxic blood. The female Photuris firefly, will lure other firefly species in by copying the blinking pattern of the males. When the male lands to mate with the Photuris, she will eat him instead. Ingesting the other firefly not only gives her a meal, but helps to protect her from other predators. The Photuris firefly doesn’t produce any defensive toxins so when she ingests firefly species that do, she is giving herself a dose of toxic protection.

Our recent world has not been kind to fireflies. Populations across the globe are declining. Research seems to suggest that the main factors leading to this worldwide decline include habitat loss and light pollution. Consider letting your fields and meadows grow long this summer, switching your outdoor lighting to firefly-friendly lighting which involve such strategies as using amber to yellow bulbs, shielded light fixtures that point down and only lighting areas when necessary. Think about how you and your family can help protect and preserve firefly habitat and consider participating in Mass Audubon’s Firefly Watch citizen science project at https://www.massaudubon.org/get-involved/citizen-science/firefly-watch.

But most of all, this summer fill up your heart with nature’s own quiet fireworks display – fireflies flashing in a dark summer field.

Susie Spikol is the Community Program Director for the Harris Center for Conservation Education in Hancock