Cause for Concern: Why Firefly Numbers are Flickering Out

There’s an undeniable magic to fireflies, an ephemeral charm that touches people of all ages. Also known as lightning bugs, fireflies are found around the world — or are they? The recent decline of firefly populations in all of their known locations remains a startling mystery. Scientists are struggling to understand why fireflies are on the decline and, more importantly, what can be done to save them.

Here’s everything we know about our dwindling firefly populations and how you can help save them.

Are Firefly Populations in Decline? The Hard Truth

According to multiple studies and observations, firefly populations around the world have been in decline since the early 2000s. The decline is so troubling that the IUCN SSC Firefly Specialist Group was created in 2018 to further study which species and locations are experiencing heightened threats of extinction.

While less than 10% of all firefly species have been studied by the Firefly Specialist Group thus far, nearly 20% of the studied populations face impending extinction. In North America alone, at least 18 distinct species are labeled as threatened, endangered, or nearing extinction. Beyond the United States and Canada, fireflies face similarly disheartening statistics.

Given the cultural and historical significance of lightning bugs, the question of why echoes around the world. Why are these charming, revered insects at risk?

Why Are Firefly Populations Declining?

Many of the threats fireflies face are threats to all of us — but especially insect and animal populations. These are the primary reasons why fireflies are disappearing, according to studies and scientific efforts:

An Overabundance of Light Pollution

To understand why fireflies are declining, it’s important to grasp how these unique bugs reproduce. Using bioluminescent patterns and signals to seek potential mates, fireflies require ample darkness to interpret these mating rituals accurately.

Light pollution and artificial lighting at night disrupt the reproductive cycle of fireflies, many studies note. The bugs grow confused in the presence of artificial light, both during the mating process and the act of larvae dispersal. Conservationists suggest there’s little to be done to prevent light pollution, as the overall brightness of our world continues to grow at an alarming, unrestricted rate.

Habitat Loss Every Single Day

Much like light pollution, fireflies face habitat loss due to constant human industry. Given that they are beetles undergoing metamorphic changes, fireflies require safe breeding grounds to allow their larvae to age. Even once their young have matured, fireflies tend to return to and prefer the same breeding grounds for courtship and living out the rest of their life cycle.

Not only are preserved habitats disappearing daily, but many species of lightning bugs also require hyper-specific habitats in order to breed. Most fireflies prefer wetland regions or locations high in humidity and freshwater access. Due to commercial, residential, and agricultural developments around the world, these niche habitats are dwindling.

Tourists Are Part of the Problem

There are locations around the world that celebrate fireflies, with roughly 12 countries hosting over a million lightning-bug-obsessed tourists every year. Japan in particular dedicates many parks and green spaces to firefly viewing events in the warm summer months. However, any locations facing overtourism also face increases in infrastructure, development, and people who may not be respectful of the habitats they visit.

Pesticides Kill More Than Pests

One of the more obvious reasons fireflies are on the decline is the high usage of pesticides in both commercial and residential agriculture. While fireflies may not make their homes in the average farm field, pesticide runoff and aerial dispersal are highly responsible for killing these populations. Given how long pesticides can linger in the environment as well as the firefly’s preference for watery habitats, it’s no wonder they encounter such threats.

Climate Change Alters Us All

We are all affected by climate change, even the smallest creatures on Earth. With rising sea levels and droughts occurring around the world, fireflies are in a constant state of flux as their habitats morph unexpectedly, quickly, and permanently.

How Can We Protect Firefly Populations?

The question remains: what can be done to protect our firefly populations worldwide? While global, big-picture issues remain too daunting to tackle, there are still steps you can take to help preserve the firefly population in your local area.

Craft a Firefly-Friendly Backyard Habitat

If you own your property and want it to become a firefly-friendly place, there are many changes you can make. For example, keeping your grass unmowed or shaggier than average can protect firefly larvae. Likewise, leaving your leaves unraked and your soil undisturbed keeps these ground-bound bugs safe until maturity. Native plants are also always a good idea!

More Water = More Fireflies

The majority of firefly species prefer humid, watery, or wetland habitats. If you have the space, incorporate more watery elements into your backyard, such as fountains, ponds, birdbaths, and streams.

No Need to Illuminate

When summer arrives and the firefly mating process is in full swing, it’s important to be mindful of your nighttime light pollution. Leave your patio and porch lights off as much as you can and be mindful of your lightning bug neighbors!

Avoid Pesticides and Keep Things Natural

Your garden may benefit from pest control, but make sure chemical pesticides aren’t utilized to accomplish this. In fact, fireflies can be fantastic companions in any garden, consuming pesky bugs and coexisting with pollinators. An all-natural garden and landscape is one of the best ways to encourage your local firefly population!