Firefly Lifespan: How Long Do Fireflies Live?

Firefly flying away from a child's hand,
© Suzanne Tucker/

Written by Volia Schubiger

Updated: June 27, 2023

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Fireflies are a kind of bug that many of us hold near and dear, remembering when we first caught one on a warm summer night. Peeking into our clasped hands as we stared at the illuminating bug, we were filled with such child-like joy. As much as we enjoyed looking at this bug, did you know there’s so much more to the firefly than meets the eye? Join us as we go over all of the fascinating facts there is to know about this little lightning bug. We’ll also uncover the firefly lifespan and other amazing facts!

The Rundown On Fireflies

firefly on leaf

Fireflies are nocturnal members of the


, a family of winged beetles.


Did you know there are over 2000 different species of fireflies? Contrary to the name, fireflies are not actually flies but are instead classified as a type of beetle. Depending on what species of firefly it is, only some can produce light. The most common fireflies that we see in North America that can glow are the Photinus Pyralis. Beneath their abdomen, fireflies have organs that are specifically dedicated to producing light.

As fireflies take in oxygen, they combine it with a chemical they create called luciferin, which in turn helps them produce their bright glow. How fireflies produce light is also known as bioluminescence. What happens to be most interesting about these little bugs is that the light that they create produces absolutely no heat! Their light is known as a “cold light.”

Fireflies use their lights to blink in patterns, each unique to the species. These lighting patterns can be used to help them find potential mates. Studies have shown that higher flash rates and intensity in males will attract more females. Fireflies also use their lights as a form of self-defense. They blink to warn predators that they will leave an unpleasant taste in their mouth if eaten since they produce defensive steroids that make them unappetizing to prey.

Now that we’ve learned a little bit about fireflies, let’s move on to explore the firefly’s lifespan!

How Long Do Fireflies Live?


Fireflies have a short lifespan of 1 to 2 years.

©Fer Gregory/

The average firefly lifespan is roughly one year in the wild. Fireflies typically only live for about two months as adults, but it accounts for about a year or two throughout their life cycle.

With over 2,000 species of fireflies on the planet, there will inevitably be some variation in their lifespan. Thanks to their luminosity, some species may survive in the larval stage for up to two years.

Adult fireflies only survive long enough to mate and lay eggs, therefore not needing to feed. This is also because of how short their lifespan is.

During their adult stage, they are only able to fly and lay eggs for around two months.

The Average Firefly Life Cycle

Like many other bugs, fireflies go through the four stages of metamorphosis: egg, larva, pupa, and adult! Let’s go through each one so we can truly understand how the lifecycle of a firefly unfolds.


Once they have mated, fireflies can lay up to 500 eggs. Female fireflies prefer to lay their eggs in damp soil covered by leaves and other debris. This process usually occurs during the middle of summer, and the eggs will eventually hatch in three to four weeks.


Throughout the late summer is when the firefly eggs will begin to hatch. This leads us to our second stage, larva. Firefly larvae will spend this entire stage of life living throughout the soil as they are not able to fly yet. Although not all species of fireflies will glow as adults, they all do as larvae. 

Some refer to these larvae as glow worms, as you can see them begin to produce a steady dull glow. Their diets consist of hunting worms, snails, and slugs. Larvae hunt by using their digestive enzymes to inject their prey, which leaves them immobilized. They then liquefy the prey’s remains for consumption.


During late spring, firefly larvae are ready to begin the third stage, which is pupating. Depending on the species, firefly larvae can pupate in different ways. One species of larva will build mud chambers in the soil and settle within it. Another species will stick itself onto a tree bark and hang upside down, similar to a caterpillar.

Once the firefly larvae have chosen how they will pupate, an incredible transformation known as histolysis occurs. This process begins with the larvae body being broken down as the transformative cells begin to activate. Once the transformative cells have been activated, this triggers the biochemical process that turns the larva into an adult. Several weeks after pupation is when the adult firefly is ready to emerge.


As mentioned earlier, the adult stage of a firefly only lasts around two months. The main priority of an adult firefly’s short life is to reproduce – that’s it! Male fireflies will use their light to blink in a specific pattern to attract a mate. If a female is interested, she will reciprocate the pattern in response. Once having mated and reproduced, the firefly will die soon after. Then the life cycle will be repeated all over.

What Factors Shorten A Firefly’s Lifespan?

isolated firefly

Each firefly species has a distinct hue of light that it emits.

©Elliotte Rusty Harold/

Although short, the lifespan of fireflies is affected by various things. Scientists have noticed a decline in fireflies recently.

Some of the factors contributing to the loss of fireflies are:

  • Light Pollution: Building lights and bright street lights have been making it difficult for fireflies to communicate with each other throughout the mating season. Light pollution contributes to the interference of their signaling pattern. Car headlights passing by can also interfere with a firefly’s synchronous patterns as well as bright lights from houses and stores.
  • Habitat Destruction: Fireflies can be incredibly picky about their habitats. Once these habitats are destroyed, it can be very difficult for them to recover. Due to residential development and urbanization, these environments are being taken away, leaving many fireflies without homes and in decline.
  • Pesticides: Lawn chemicals and pesticides are also considered a huge danger to fireflies. Fireflies prefer to lay their eggs in soil and because of the high usage of insecticides, their eggs and larvae are exposed to these insecticides and die before reaching adulthood.

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About the Author

Volia Schubiger is a freelance copywriter and content editor with a passion and expertise in content creation, branding, and marketing. She has a background in Broadcast Journalism & Political Science from CUNY Brooklyn College. When she's not writing she loves traveling, perusing used book stores, and hanging out with her other half.

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