What you can do about the decline in fireflies
For as long as humans can remember, a mysterious sparkle on warm summer nights turned the evening magical, as kids raced through yards and fields to get a closer look at that sparkle.
It would be tough to find an adult who did not have a jar full of sparkling fireflies at some point in their lives. These memories have been in jeopardy in recent years, as fireflies all across the country have significantly declined. Scientists are racing to learn how we can all help to keep the twinkle going.
About the firefly
Fireflies are not a single species; there are more than 2,000 different species of fireflies! Each species acts a little differently than the others. The firefly species in the western United States do not light up at all.
Adult fireflies lay eggs just beneath the soil. The eggs hatch in larvae, which are carnivorous. They feed off of snails and small insects. Depending on the species, the larvae will transform into adult fireflies sometime between two weeks and a year. Adult fireflies are most often herbivores and feed on plant nectar or pollen. Some species of adults do not eat at all as their adult life span is so short.
What about the glow?
Fireflies produce the most efficient light in the world. Regular incandescent light bulbs only produce 10 percent light (the rest of the energy is wasted to heat). The new CFL or LED light bulbs produce 90 percent light. That’s great, but the efficient firefly converts 100 percent of the light-producing energy to light.
It is called a “cold light.” The glow is produced when an enzyme called luciferase is present. When combined with oxygen, calcium, ATP, and a chemical called luciferin, the enzyme glows.
Fireflies use the blinking lights to attract mates and communicate. A male firefly will flash a signal and, if interested, a female will repeat the signal back. There are a few species of fireflies that use their flash in more devious ways. Those species eat other fireflies. They flash their lights to attract females of another species, then eat them when they come to mate.
The glow of the fireflies also protects them from predators as it serves as a warning that they are not tasty. Fireflies contain chemicals that taste quite bad to predators, and in some cases, they are toxic. The blinking light warns of this bad taste. Even the eggs and larvae of fireflies often glow to simply warn of their bad taste.
It’s not just the adult firefly that lights up. The larvae and even the eggs of some firefly species glow underground while developing. Scientists believe that this is just another way that the species warns that they do not taste good — so don’t eat them.
Synchronous twinkle
As if the firefly twinkle wasn’t magical enough, there is a species in the Great Smoky Mountains that has learned to twinkle in unison. For 2-3 weeks a year, this creates a forest that pulsates flashes of light and thrills crowds of people who reserve spots to watch their display. The species, photinus carolinus, sends out 5-8 flashes of light followed by 8 seconds of darkness.
All species of fireflies have flash patterns, but what makes this species unique is that they are able to all coordinate their flashes so each flash happens at the same time.
Decline of the twinkle
Despite the long history of fireflies, scientists do not yet fully understand them. However, it has been clear that the creatures have been in decline for quite some time.
Most believe it is because of the development of cities and light pollution. When the field they are in is bulldozed, they simply disappear instead of moving to a new place.
And because the fireflies use blinking lights to mate, a developed area that has too many lights at night will prevent the fireflies from mating, and that population will disappear. Changing climate is another factor because fireflies need moist grounds for their larvae to develop.
How can you help?
Scientists believe you can help fireflies on your property by turning your outside lights off at night, not spraying insecticides in your yard, allowing part of your yard to have longer grass or landscaping, and planting trees.
These simple steps might ensure that future kids also will get to chase the magical lights that show up on warm summer evenings.
Mike Szydlowski is a science teacher and zoo facilitator at Jefferson STEAM School.
TIME FOR A POP QUIZ
Why is firefly not an accurate name for these creatures?
Why can the twinkle of the firefly be considered flirtatious?
What is so impressive about the firefly light?
What are the three major causes of the decline of the firefly?
What can you do at home to help fireflies?
LAST WEEK'S QUIZ ANSWERS
Are forest fires bad? Explain.
Not necessarily. Forest fires clean up a forest and the ecosystem depends on an occasional fire to keep it healthy.
Why have humans backed off on fighting every forest fire?
When humans stop a forest fire, the dead wood on the forest floor continues to accumulate. Therefore, when a fire does occur, it is so intense that it cannot be controlled and causes more damage.
Why was New York so smoky from fires that were not even in their state?
The smoke from the Canadian fires hit a low-pressure system in Maine. The counter-clockwise spin of the low made the smoke travel right to New York.
If climate change was not occurring, would we have forest fires?
Yes! Forest fires are a natural occurrence and have happened well before humans were on Earth.
How is climate change making fires more dangerous?
Climate change is causing droughts in areas that contain huge forests. The forests are drying out, and when a natural fire does occur, it is far worse than it used to be.
This article originally appeared on Columbia Daily Tribune: What you can do about the decline in fireflies
