Community Magazine July 2016

The tiny firefly uses its light for signaling. The system is not unlike the Morse code, as once used by naval signalers working with hand lamps. But the fireflies’ version is much more complicated. Morse code uses just two kinds of flashes, one short and one long. Firefly flashes vary considerably in length, some lasting for as much as five seconds, and others being repeated forty times within a single second, at a speed so swift that human eyes are unable to perceive the intervals between them. In the United States, fireflies operate individually. There are several different species, which often occupy the same meadow or woodland. The males are much smaller than the females, and outnumber them by as many as fifty to one. Finding an unattached female is an extremely competitive business. The display starts soon after sunset, and lasts for an hour or so. The females emerge from their burrows while the males cruise through the air flashing their presence, each species using its own characteristic code. One species produces long bursts at the rate of a flash every half-second. Another makes two flashes a second apart and then stops and waits. A third makes only single sporadic flashes. The most common response from the females of all species is a single short flash, but the time they allow to elapse before making their response is critical, and a searching male will not take notice of a reply unless it comes at the correct time interval after he has concluded his call. We know that curving trails of colored light help to attract customers to a fairground. It is amazing to realize that the colored signals of diminutive insects are performing the same function. The difference is that the fairground requires a generator and energy consumption to produce its effect, while the glowworm or firefly achieves this chemically and without effort. In fact, the “fire” of the fireflies is a misnomer, for the light they produce is cold, and in energy terms, remarkably efficient. Whereas most electric bulbs waste 97 percent of their energy in heat (to test this out just place your hand over a reading lamp), a firefly concentrates 90 percent of its effort into light. How does the firefly do it? A complex protein called luciferin , when mixed with small quantities of an enzyme called luciferase, will combine with oxygen and in the process give off a bright glow. The luciferin is stored behind areas of transparent cuticle backed by dense tissue that acts as a reflector. The glow emerging from so tiny an animal, though scarcely dazzling, is sufficient to read a printed page. Indigent Japanese students, too poor to afford other lighting, used fireflies to illuminate their nocturnal studies. In parts of South America, fireflies were enclosed in perforated gourds for domestic lighting. The common European glowworm is another shining example of a species that has the ability to create its own light. European glowworms frequent damp hedgerows and meadows. They are most active in June and July, when wingless glowworms ascend tall grass stems and hang, heads down, twisting their bodies to expose their greenish lanterns. The winged glowworms can pinpoint these tiny signals from up to 100 yards away. Anyone who lives near an airport will see planes approaching the runway at night. Powerful beams of light mounted on the wings cut through the darkness on the plane’s descent. During the descent, before the plane has come to a complete stop, and passengers are reminded to take all their personal belongings with them, the lights are dimmed. All the intelligence that has been utilized in the construction of the plane dims into insignificance when compared to the intelligence demonstrated by the diminutive creatures of Creation. European Glowworm Listen to this amazing story. In New Zealand, there is an insect called a fungus gnat that uses light to attract its prey. Its larvae (the juvenile stage between hatching and adulthood in those species of animals in which the young have a different appearance and way of life than the adults) live in many places – beneath bridges, under the overhangs of damp sheltered banks, and within hollow trees. But they are most famous for gathering by the millions within caves. Each of them secretes a tube of clear mucus which it suspends from the ceiling of the cave where it lives. From this mucus tube the fungus gnat larva hangs several dozen threads, each beaded with globules of sticky, adhesive glue. As it sits within its translucent home, it glows with a steady unblinking light so that the whole ceiling shines like the Milky Way. The light attracts midges and moths, which become entangled in the threads. The larvaeabove, when they sense the vibrations causedby the trapped insects, bite a hole through their tube and haul up the thread with their mandibles (lower jawbones), like fishermen reeling in their catch. Try working out how many separate inventions there are in that little story. Edison and Swan utilized their not inconsiderable intelligence to invent the electric bulb. The illuminating examples of lights found in the animal world indicate even greater intelligence. The question is: From where does all that intelligence come? Certainly not from the inventors or from the animals themselves. Try and grow a light bulb from your head. Try really hard! The larva of the fungus gnat is just a little less intelligent than you and its life depends on its luminous stunt, and its expert knowledge of the glue it produces. How did it manage this? Who told the insects about luciferin and luciferase? Who taught them chemistry? The answer is that intelligence does not come from nowhere. It has a source. And that source is the greatest Intelligence of all. Tuvia Cohen, is a humorist, scientist, and an accomplished author. This article was adapted from an article that appeared in ‘The Jewish World of Wonders’. Firefly SIVAN - TAMUZ 5776 JULY 2016 87