Remember the joy of catching fireflies in a jar when you were a child? Unfortunately, future generations may not enjoy the same opportunity. These magnificent creatures are disappearing at an alarming rate, and scientists fear that they may go extinct.
So why are fireflies going extinct, and what’s behind the disappearance of the lightning bugs, as some folks call these critters? Unfortunately, multiple causes play a role, but they all stem from human causes. Here’s what you need to know about the mysterious flying glow worm and how you can play a part in saving them from the brink.
What Are Fireflies?
Fireflies are so unusual that they seem like an alien species. However, in reality, they are a type of beetle. There are approximately 2,000 species of this fascinating insect spread throughout a variety of warm environments, as well as more temperate regions (1). They love moisture, so they tend to make appearances in more humid climates.
You can make an educated guess about where a person lives based on their name for this illuminated critter. For example, in England, people typically refer to them as glow worms, although some reserve that term only for the larvae. In some parts of the south, they refer to these creatures as moon bugs, and folks on the mid-Atlantic coast call them lightning bugs, although they don’t predict summer storms. Other monikers include fire devils, big dippers and blinkies.
Like other beetles, fireflies are a part of the order Coleoptera, and they share in common the secondary pair of hardened forewings that serve as protective armor for the functional wings hidden underneath (2). Their bodies consist of three distinct areas — the abdomen, thorax, and head. Like other insects, they have six legs and compound eyes. They also have two pairs of antennae. The pyralis species is the most common firefly in North America.
What Makes Fireflies Glow?
What sets fireflies apart from other beetles is the illuminated tip of their abdomens. How do they produce this wonder? The magic occurs through a process called bioluminescence. The bodies of fireflies contain a chemical called luciferin (3). When this substance combines with oxygen and adenosine triphosphate (ATP), it produces a glow. Unlike incandescent bulbs, however, the type of light these critters provide emits little if any heat. If it did, the poor creatures wouldn’t survive.
Insects do not have lungs, but they do “breathe” air through a complex series of tubes called tracheoles. However, fireflies don’t have sufficient muscle power to flood their abdomen with enough of a supply to produce the rapid-fire flashes that light up summer skies. Fairly recently, researchers discovered that nitric oxide gas, the same gas your body produces when you take Viagra, plays a crucial role. When the flow of nitric oxide stops, so does the glow.
Why Do Fireflies Glow?
If the above passage made you guess that fireflies light up as part of the mating process, you win a prize. Contrary to popular belief, both male and female fireflies illuminate, but females have protective armor around the part of their abdomen that glows, making them less bright (4). Females are attracted to specific flash patterns in males. Much like human rock stars, those with the flashiest and brightest colors attract the most feminine attention.
Fireflies light up for more than making baby lightning bugs, however, Their glow also serves as a warning to predators. These insects produce defensive steroids in their body that makes them unpalatable to other critters, and their lights signal, “You won’t find a tasty snack here, buddy.” While the larvae of all species of this insect light up, not all adults do. Some use pheromones instead of illumination to attract mates.
Are Fireflies Going Extinct?
If you live in an area where these fascinating creatures make regular appearances in the night sky, you might look forward to the magic as the days grow warmer. However, you might want to enjoy the wonder while you still can. Tragically, scientific research indicates that these magnificent animals may go extinct before long.
However, people won’t lose fireflies due to natural disasters or invasive predators. Instead, the factors influencing their demise stem from human causes — which means proactive changes can protect these magical creatures. Specifically, artificial lights, habitat loss and pesticides threaten the continuity of lightning bugs the most.
Here are three ways that fireflies are going extinct:
1. Artificial Lights
Unless you are lucky enough to live in an International Dark Sky Community, the streetlights you rely on to tell your kids when it’s time to head home could harm the fireflies (5). Indeed, light pollution is the second leading cause of driving extinction. Humans still have time to stop the irony of losing a creature known for their illumination to too much of the bright stuff.
The reason that lights impact fireflies so much is that it interferes with their ability to mate. Because these creatures depend on highly organized patterns of flashes to signal to prospective breeding partners, bright nighttime skies keep them from being able to see the messages that others in their species send.
Even when a fellow lightning bug does get the memo, they may not reproduce. Researchers constructed mesocosms consisting of mesh-covered canopies to study the impact of light on firefly mating (6). They then used a fluorescent powder on the male genitalia so that they could search for traces of residue on the females to ensure mating had occurred. They found that light not only decreased mating behavior but lowered the success rate, too.
Compounding matters is the short mating season that fireflies enjoy. These creatures spend most of their lives in the larval stage, and they only have a few weeks as adults to mate. If they miss the opportunity, their insect bloodline dies with them.
If there is a bright side to this problem, it’s that similar research revealed that increasing the amount of light exposure did not render fireflies more vulnerable to predators. That buys humans a bit of time to implement measures to decrease light pollution. Unfortunately, the glow of fluorescents and neons isn’t the only threat that these creatures face.
2. Habitat Loss
There’s no doubt that human beings continue to encroach on animal habitats. Today, the number one threat facing the fireflies is habitat loss due to the development of wetlands (7). While the population decline affects all species of this natural wonder, people may have already lost some unique varieties permanently. For example, the Bethany Beach firefly only inhabits a narrow swath of coastal habitat along the Atlantic shore in Delaware. Bulldozers have already begun firing up in the region.
Unfortunately, the areas that fireflies tend to inhabit are also desirable to people. Since times immemorial, human beings have flocked to live along waterways, and coastal regions are particularly in high demand. When it comes down to a battle between wealthy developers and conservationists, those with the deepest pockets often win in court.
The problem of habitat loss extends beyond well-to-do homeowners craving beachside luxury, though. In other parts of the world, these creatures face additional threats.
For example, in Southeast Asia, congregating fireflies typically come together among the mangrove trees to synchronize their flashes to attract mates. This behavior provides a dazzling light show for tourists, but it isn’t enough to stop the ravishes of greed and the human desire for convenience foods. Many of these areas are now being cleared for oil palm plantations (8). This oil is a staple in dishes from ramen to snack dips. The destruction of habitats for palm oil could not only rob people of orangutans but multiple species of glow worms, as well.
Finally, pesticides pose an additional threat to these fragile creatures. It’s only logical that the preparations that farmers use to keep other beetles, such as boll weevils, out of their crops, would harm members of this species, too. However, the problem extends beyond massive agricultural enterprises. Many individuals use pesticides with chemicals like neonicotinoids that get into the soil where larvae grow. This seepage also threatens snails and slugs, two of the primary food sources for fireflies.
Additionally, many popular lawn fertilizers now include ingredients to fight insects, which further decimates firefly populations (9). Using multipurpose applications designed for an extensive series of pests can mean that your children won’t get to enjoy the wonder of seeing their lawn lit up by tiny fairy lanterns or catching these critters in a jar.
Even if people stop using pesticides today, it will take time for current populations to bounce back. This effect isn’t only due to light pollution and habitat destruction. Commercial pesticides can linger in the soil for four to five years, meaning that even if new adult insects return to the region, their young may not survive to adulthood (10). Although agricultural trends tend toward shorter-acting pesticides that don’t lead to long-term contamination, those areas that have experienced heavy use may never see populations return.
What Can We Do to Save Fireflies?
If you’re concerned about the fate of the fireflies, there is a lot that you can do to help. A combination of individual and community-based action initiatives can hopefully prevent the destruction of these gorgeous creatures.
1. Actions You Can Take Individually
Changing your behaviors and lawn-maintenance habits can significantly improve the chances of survival for any fireflies you see around your home. Here are some steps you can take:
- Go for organic, pesticide-free fertilizer: When you select your lawn treatments for the growing season, seek out those catered explicitly for your region. These not only will do a more effective job of controlling unwanted weeds, but they will also target a narrower spectrum of insects. Another alternative involves using organic fertilizer such as manure with low nitrogen content.
- Try xeriscaping: Are you tired of spending the better part of your weekend downtime laboring in your yard? Why not consider a complete overhaul that ditches much of your grass in favor of more eco-friendly xeriscaping? In this approach to design, you use native plants that thrive without chemical fertilizers and excess watering. The advantages include less time spent on upkeep — and more money in your pocket over the long-term. If you want to go a step further to help fireflies, you can install a water feature such as a pond or fountain to raise humidity levels and make your lawn more attractive to these creatures.
- Turn off your lights: Unless you are expecting a late-night pizza delivery, is there any reason to leave your porch lights on all night long? Doing so consumes energy and can keep fireflies from mating. Plus, it draws moths, which you don’t want flying in when you open your door — at least, if you prefer uneaten sweaters. If you must light up the outdoors, find out what species of firefly flourishes in your region. Select a light color such as blue that doesn’t shine too brightly or confuse lightning bugs looking for love.
- Build responsibly: If you have considerable acreage, take a look around at dusk before you break ground on your next shed or greenhouse project. If you find a patch of your land with many glow worms or firefly larvae, see if you can relocate the build to another spot with a less dense population.
- Buy organic: Because pesticides pose a significant threat to firefly populations, buying organic produce can help indirectly. The more consumers demand products grown without dangerous chemicals, the sooner large agricultural industries will alter their practices.
2. What You Can Do with Your Community
Individuals can only do so much. If you are ambitious about saving fireflies, here are ways to get involved with others who also care (11):
- Start a dark sky initiative: It can prove challenging to get everyone on board with a dark sky initiative in your hometown, but if you eventually succeed, you’ll reap benefits beyond saving fireflies. You will see scores of stars that you never knew existed. You will face considerable opposition from business leaders and those concerned about crime. However, you can take a long-term approach of supporting political candidates who likewise consider the benefits of turning out the lights worth it.
- Sign up with a firefly watch group: Because they are endangered, many areas have firefly watch groups that help keep counts of local populations. A Google search reveals the places that need help, so pick up your phone and get in touch.
The Bottom Line
Most of us have magical memories of catching fireflies as children. But sadly, these gorgeous creatures are going extinct. If you don’t want this wonder to disappear for future generations, educate yourself about these creatures, and get involved in conservation efforts today.