Why Are Fireflies Disappearing From the Hudson Valley?

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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.

Too Much Light At Night

Scientists don’t know enough about fireflies to tell for sure. But the signs are indicating light pollution as a major factor in the disappearance of fireflies all over the world.

Both male and female fireflies use their flashing lights to communicate. Some species synchronize their flashes, sometimes across large groups of thousands of insects. All species speak a language of light—scientists believe they use it to attract mates, defend their territory, and warn off predators.

Human light pollution is believed to interrupt firefly flash patterns. Scientists have observed that synchronous fireflies get out of synch for a few minutes after a car’s headlights pass. Light from homes, cars, stores, and streetlights may all make it difficult for fireflies to signal each other during mating—meaning fewer firefly larvae are born next season.

Where fireflies once had uninterrupted forests and fields to live and mate, homes with landscaped lawns and lots of exterior lights are taking over. The reduction of habitat and the increase in lighting at night may all be contributing to make fireflies more rare.

Fireflies are fascinating creatures that light up our nights and bring a sense of magic and mystery to our environment. If they disappear, it will be a great loss to habitats and generations of people all over the world.

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.

Segment Guests

Sarah Lower

Sarah Lower is an assistant professor of biology at Bucknell University in Lewisburg, Pennsylvania. 

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Sara Lewis

Sara Lewis is a professor of biology at Tufts University in Boston, Massachusetts and author of Silent Sparks: The Wondrous World of Fireflies (Princeton University Press, 2016).

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The purpose of blinking is so that male fireflies can find potential mates. If you watch long enough you will be able to pick up on their unique flash pattern. Try to remember it so that next time you see a firefly flash you can identify it.