If you live on the Eastern side of the United States and spend warm summer nights outside, your eyes have probably been treated to some wondrous visual displays this week – besides Independence Day fireworks displays.
It’s the best time of the year to experience the twinkling enchantment of fireflies – sometimes swarming to rival the beauty of the Christmas tree at Rockefeller Center.
Ever wonder what makes them tick – or light up? Here are some facts that make them all the more interesting – if not downright miraculous.
1. They’re not “flies” at all, but beetles. They are nocturnal members of Lampyridae, a family of insects within the beetle order Coleoptera, or winged beetles. The family name, Lampyridae comes from the Greek “lampein,” meaning to shine … just like a lamp.
2. How do they light up? It’s all in their chemistry. When a chemical called luciferin inside their abdomen/tail combines with oxygen, calcium and adenosine triphosphate, a reaction occurs that creates their spectacular light through bioluminescence.
3. Why do you only see this phenomenon in the East? Apparently, the chemical reaction only happens in the magic of the East. There are fireflies out West, but they don’t light up. There are actually some 2,000 kinds of fireflies, or “lightning bugs,” but only some are equipped with the ability to glow momentarily – and they evidently like the East Coast. No scientist has really come up with a better explanation.
4. It is said that firefly light is the most efficient ever produced because nearly 100 percent of the energy used to produce the chemical reaction is emitted as light. By comparison, an incandescent light bulb only emits 10 percent of its energy as light, the other 90 percent is lost as heat.
5. Each kind of firefly has a specific pattern of light flashing, and males use this pattern to let the females know that they would be a fine match for one another. When a female notices a suitable suitor, she replies with her own specific flash sequence. That’s when the firefly fireworks begin.
6. If you have ever seen hundreds or even thousands of fireflies lighting up in a seemingly synchronized fashion, it’s truly a breathtaking spectacle. Only some kinds of fireflies do this, though it can be equally stunning when fireflies, for whatever their reasons, choose to swarm a particular tree or pasture. The erratic twinkling can be as amazing as the synchronized blinking. Photinus carolinus is the only species in America that flash simultaneously. A great place to witness this is the Great Smoky Mountains National Park which has firefly tours.
7. It’s not your imagination that they light up in many different hues – from yellow to light red and even green and orange.
8. Fireflies of all kinds have a built-in protection against predators like birds. They apparently taste awful. Firefly blood contains lucibufagins, a defensive steroid that tastes bad and would-be predators have largely figured this out – avoiding bugs that light up.
9. They light up underground, too. As larvae, firefly offspring emit a subterranean glow. With some kinds, even the eggs glow. Some firefly larvae live in the water and have gills and sup on aquatic snails, before inching their way to solid ground for their next phase in life.
10. What do they eat? Most fireflies live on pollen and nectar, but others have stranger diets. The underground-dwelling larvae of the lightning bug is carnivorous and feast on slugs, worms and snails. Once they grow up, some move on to eat other fireflies. Even more bizarre – some don’t eat anything at all during their short lifespans.
11. How do fireflies control their lights? Since insects do not have lungs, they send spurts of oxygen to their lamps through interior cells within through a complex series of successively smaller tubes known as tracheoles. Researchers only recently learned that nitric oxide gas (the same gas that is produced by taking the drug Viagra) plays a critical role in firefly flash control. In short, when the firefly light is off, no nitric oxide is being produced. In this situation, oxygen that enters the light organ is bound to the surface of the cell’s energy-producing organelles, called the mitrochondria, and is thereby not available for transport further within the light organ. The presence of nitric oxide, which binds to the mitochondria, allows oxygen to flow into the light organ where it combines with the other chemicals needed to produce the bioluminescent reaction.
12. Fireflies live in various habitats, but prefer life east of the Rockies and even east of Kansas. Most live in forests, fields or the margins between them. Some live in more arid areas, but they typically follow the rainy season. Fireflies are found all over the world, from North and South America to Europe and Asia. They also like warm, humid weather.
13. Most firefly species have one thing in common – standing water. They live near ponds, streams, marshes, rivers and lakes, but they don’t need a lot of water to get by. Vernal pools and small depressions that hold water during firefly mating season can all provide the habitat fireflies need.
14. For whatever reason, fireflies also love long grass. They’re nocturnal, and during the day they spend most of their time on the ground. At night, they crawl to the tops of blades of grass and fly into tree branches to signal for mates. Long grass conceals the fireflies better and allows them a better vantage point for signaling at night, and over-mowing your lawn may disturb your firefly population.
15. When is peak firefly season? In years when summer-like weather arrives before June does, fireflies tend to appear in lawns, gardens, and trees earlier than usual — sometimes as early as late spring. All the warmth from early summers and mild winters fools lightning bugs into thinking it’s later in the season than it really is, and so they emerge sooner. Mild winters also mean a larger lightning bug population in your back yard, since the young will have had an easier time surviving the cold. Wet springs also lead to earlier firefly flash displays.
