Twilight Blinkers and More!

Did You Know…?

  • …that there are more than 1900 species of fireflies?
  • …that most fireflies turn on their light only about once a second; but some fireflies produce two flashes a scant l/30th of a second apart, which the human eye detects as only one flash. Other species flash only once in several seconds?
  • …that many fireflies live only a few weeks?
  • …that fireflies are really light-making beetles?
  • …that firefly light is among the most efficient energy known. An electric light uses only 10 percent of its energy as light, and 90 percent is lost as heat. By contrast, the firefly’s light is 95 percent light.
  • …that in some areas, millions of fireflies in a single tree blink their lights in almost perfect synchronization?
  • …that the blink of the firefly seems to be largely without purpose—which undermines the theories of evolution yet more, if it is consistently true that the fittest survive.
  • …that scientists today have identified several dozen species of luminous fungi.

Did you ever step out into the backyard on a warm summer evening just at twilight and watch for the first flicker of a firefly? This tiny creature, less than an inch long, is one of the marvels of God’s creation.

The firefly, along with various light-producing fish, squids, and mushrooms, have intrigued scientists for centuries. More than 2,000 years ago Aristotle wrote, “Some things, though they are not in their nature fire nor any species of fire, yet seem to produce light.” They were baffled by the glow sometimes seen in the ocean, which they called “sea fire,” which is actually produced by minute living organisms.

The firefly has an almost incredible family. The North American firefly, known to most of us as a lightning bug, is one of some 1900 species of fireflies. And it is one of more than a quarter million species of beetles that have been identified.

In the daylight the firefly seeks shelter from the sun by hiding on the underside of leaves. Small, striped and green, it can easily be mistaken for a cucumber beetle.

What is the tiny beetle’s secret for making light? The light is produced by a substance called luciferin which is stored in a tiny organ on the underside of the beetle’s tail. The organ is shaped like the headlight of an automobile, with a transparent window backed by a substance that acts as a reflector. The firefly lights up when air exhaled from its respiratory system strikes the luciferin, changing it into another chemical which oxidizes for an instant, creating the cold light. Immediately the chemical changes back to the original compound, and the process is ready to be repeated. If fireflies are deprived of oxygen, they cannot make light.

Firefly light is distinctive, however, because it is light without heat—a level of efficiency which our scientists have not been able to achieve. An electric light uses only 10 percent of its energy as light, and 90 percent is lost as heat. By contrast, the firefly’s light is 95 percent light—only 5 percent is lost as heat. Here is efficiency unmatched by any product of human design.

Who can think that the trial and error of chance could develop such a marvelous process?

Why not give glory to an All-wise, All-knowing Creator, who understands the luminescent compounds—which our scientists must study for years to comprehend?

North American fireflies do not blink their little tail-lights year-round, but only for a few weeks in early summer; and not all night, but only in the early evening, for perhaps one or two hours. The temperature and atmospheric conditions must be just right for them to come out of hiding. But before they disappear for the season, they have laid their eggs in some hidden location, guaranteeing next year’s night lights.

The life cycle of the firefly is unknown, but is believed to be very short. The larvae turn into pupa, then hatch into adults that join others, which flash their lights briefly, and within a few weeks die.

In other parts of the world fireflies are much more spectacular than in North America. In Southeast Asian countries, such as Thailand, Malaysia, Singapore and the Islands of New Guinea, swarms of fireflies may put on a light show every night. And residents say that it is not limited to a short season in summer but is a year-round occurrence.

Writing for the National Geographic magazine, Doctor Zahl, who made an extensive study of bioluminescence, told of traveling to Malaysia to observe the fireflies. What he found was a phenomena more spectacular than he could have imagined. He writes of prowling through mangrove swamps of northwestern Singapore, arriving finally in an area where fireflies were said to cluster. As night descended, he says, “a single beacon flashed high in the tree. In a short time branches and leaves were full of lights blinking away, but without any particular pattern or rhythm.” Then he tells of a change, when “fireflies clustered on a single branch began flashing on and off in unison, as though they were wired together and someone were snapping a switch at regular intervals.” In a short time other areas “picked up the synchronization, until most of the fireflies in the tree flashed in perfect time.” How do they do it? What gives these insects the remarkable ability to flash together? And the flashing is much more precise than it would be if each firefly had to see another’s flash before producing his own. Somehow, each insect is able to match his flash with that of his neighboring fireflies.

West Indies’ fireflies “shine like a first magnitude star seen with the naked eye,” so brightly that the natives tie them to their toes to light their way through the jungle. There are so many fireflies in Japan, we are told, that the Japanese hold a firefly festival each year.

And More…

Fireflies are not nature’s only night lights.

Scientists today have identified several dozen luminous species of fungi. For centuries men ascribed magical powers to tree trunks that glowed at night without being consumed, unaware that the “fire” came from bacteria or fungi growing within the rotting wood.

Certain noninjurious bacteria light up some species of squids and fish. Others produce their own light. Luminescent marine creatures include shrimp, jellyfish, sea pens, comb jellies, worms, mollusk, hydroids, and other small sea creatures.

In some parts of the world, coral rock appears to be luminescent. But it is not the coral at all, but tiny hydroids that inhabit it.

The question stumping the experts is: What is the value of this so-called “self-created light” to the organism? If evolutionary theory is true, these species should have survived while others did not because of some advantage which their luminescence gives them. In many species, the luminescence seems purely fortuitous. For example, what benefit does a marine microbe derive by being luminous, when it simply mills around myriads of its nearly identical brothers? Or what advantage has a glowing mushroom which grows beside one which does not glow? We see far more advantage in crediting these wonders of nature’s handiwork to the Supreme Creator, whose designs and purposes far transcend our feeble minds. What need for one creature to have advantage over another, except to show the handiwork of the Designer?

Again, we can observe, but we do not know the why or the how. We can only say, “The hand that made them is Divine.”

The Glowworm

There is yet another light-producing insect, the glowworm, which in reality is neither worm nor beetle but a close relative of the common housefly. These creatures lure tourists to the Waitomo Caves in New Zealand, where they congregate among the stalactites in large numbers. In the darkness of the cave, these glowworms appear like “stars.”

The glowing of these creatures has a unique purpose. These glowworms spin almost invisible threads, similar to the strands of a spider’s web. One worm may dangle as many as 70 such strands or fishlines. Each fishline is strung with pearls of deadly glue.

Attracted by the light of the glowworm, the caves’ flying insects fly towards the glow and are trapped in the dangling sticky strands. The glowworms then reel their victims in and devour them.

Although best known in these famous caves, glowworms abound throughout New Zealand. Now let us ask: did the glowworm design the formula for making its own glue? And who taught it how to spin fishlines, and to reel in its captives?

The comment of one scientist is significant: “Mystery surrounds these and all the other organisms that light nature’s nights with their cold fire, and as in so many other endeavors, the more we learn, the more there is to learn.” Says another scientist, “We must admit that nature is still far ahead of us.”

We can only bow our heads to our great and wonderful Creator, whose smallest works are beyond our comprehending. Scientists have identified the chemicals that produce the light, but they are not able to duplicate the enzyme that enables the firefly to make light, hence have not been able to reproduce the light. Yet the process goes on in the tiny firefly, day after day, year after year, millennium after millennium.

God is not depending upon us to understand His creation, much less to operate it. Our part is to reverence and serve Him, and to let everything around us keep us reminded that the hand that made it all is Divine.

Scientific Data for this Article was Taken From:

  • the National Geographic magazine, Vol. 140, No. 1;
  • “Nature’s Nightlights,” by Paul A. Zahl, Ph.D., pp. 45ff.;
  • “Nature’s Night Lights,” by R. Burton, Planford Books, England.