Back to Metroland's Home Page!
 Columns & Opinions
   The Simple Life
   Myth America
 News & Features
   This Week's Review
   The Dining Guide
 Cinema & Video
   Weekly Reviews
   The Movie Schedule
   Listen Here
   Art Murmur
   Night & Day
   Event Listings
   View Classified Ads
   Place a Classified Ad
   Online Personals
   Place A Print Ad
 About Metroland
   Where We Are
   Who We Are
   What We Do
   Work For Us
   Place An Ad

Night Light

The Aztecs saw them as rep-resenting a spark of knowledge in a world of ignorance. Today they are aiding research on cancer, heart disease and other disabling conditions. They may also help us detect life in outer space. They hang out in my garden and, as the dusk’s light dims, they provide a short-lived aerial show, stretching hyphens of greenish-yellow light along lumbering flights amid raised vegetable beds and thickening summer vegetation.

Fireflies are pretty amazing creatures. I’ve been fascinated with these bugs since I first saw their blinking lights hovering through the summer air. Why and how do they do this magic? Why do they only seem to flash about for only a short time just as darkness is setting in, and where are they all the rest of the day?

Following one flashing wonder through my garden, I focused my vision where I thought the insect would next flash. I was generally off a bit in my prediction, always looking for straight lines where such things seldom exist. The bug seemed to not take any evasive measures from my pursuit. It seemed intent on other concerns, flashing at a steady rate.

Fireflies (aka lightning bugs) are actually nocturnal beetles of the Lampyridae insect family. Their adult lives are short, sometimes flashing for as long as a week if they’re lucky. They tend to prefer warm and humid weather, with the greatest diversity of species being found in tropical areas of Asia, Central America and South America. They emerge in many parts of the eastern United States during the warm summer months, but for some unknown reason they don’t light up in the North American lands west of Kansas.

While their days of adulthood are few, most of their life is lived out in a larval stage that prefers the damp cover offered by decomposing wood, leaves and plant debris. Many species of the flashing bug tend to settle in or near sources of water, preferring ponds, streams and wetlands, though some species can survive in arid areas. When they’re not doing their aerial light shows, they’re hiding out in the cool shade of nearby plant life.

Female fireflies lay their eggs in damp earth. The eggs hatch after about three weeks into tiny larvae that some have described as appearing turtlelike in shape. Unlike the seemingly laid-back adults, these larvae are aggressive predators voraciously devouring such garden pests as snails, slugs, cutworms and mites. They have sickle-shaped mandibles through which they inject their prey with a compound that both anesthetizes and initiates the digestive process. Firefly larva (aka glowworms) are distinguished from other small critters by the glowing spots that can be found on their undersides and can remain in this larval stage for as long as two years.

In late spring, maturing larvae go into a pupa stage like butterflies, however instead of a thread cocoon, they take up residence in a tiny ball of mud. After about 10 days of entombment, the adult beetle emerges and immediately focuses its short remaining life on locating a sex partner to help ensure the next generation of flying flashers. Beneath dark-brown wing covers the adult firefly hides a yellow-green abdomen. Females tend to have smaller areas of luminescence than males.

To attract more of these beetles to one’s yard, firefly expert Marc Branham suggests reducing or eliminating the use of lawn chemicals, reducing “extra lighting” which creates “photic noise” for the bugs, and providing vegetation where the bugs can stay cool during the day.

Research indicates that the flashings of the mature firefly serve two main functions. First, they are a form of communication to potential mates. Each species of firefly has its own distinct set of flashes. Males tend to be the ones we see flashing around in the air, generally outnumbering females at a ratio of about 50 to 1. Females often remain in the vegetation below. If they see a particularly “sexy” flasher above, they will flash back and engage in a series of photic communications that may culminate in mating.

The second function of the flashing is to warn possible predators that they should avoid eating this bug. The flashing frequency of the beetles is known to increase in stressful circumstances. Among the substances in the bug’s “tail light” are lucibufagins, toxins that can be quite poisonous to potential predators. When two Australian bearded dragon lizards died in the Philadelphia Zoo not that long ago, autopsies revealed that they died from eating fireflies. A number of other exotic reptiles and amphibians not accustomed to these flashers in their natural environments, have died when they mistakenly snagged fireflies for a meal.

The light given off by these bugs is far more efficient than anything Thomas Edison could have dreamed up. While incandescent bulbs waste about 90 percent of the energy they consume in the form of heat, the simple “cold” light of the firefly converts almost 100 percent of the energy used into light. The light is produced through the action of two rare chemicals contained in the bug’s butt. Luciferin produces the light when it is acted upon by the enzyme luciferace, which functions as a chemical trigger. Oxygen is the fuel burned in the reaction and ATP (adenosine triphosphate) acts as a form of chemical fuse that causes the mix of luciferin and luciferace to go critical.

Luciferin and luciferace are important substances in health research and space exploration. These bioluminescence chemicals and their reaction to ATP (contained in all living cells) help in the detection of problems in human cells. They have furthered research on cancer, heart disease, multiple sclerosis, cystic fibrosis and antibiotics. These chemicals have also been used in electronics developed to probe space for extraterrestrial life and to detect bacterial contamination in food and water down here on the planet.

It appears that the simple little firefly has done a lot more for humans than just fascinate us with their flashing.

—Tom Nattell 

Send A Letter to Our Editor
Back Home
Save 50% With Home Delivery
Send Flowers Today 2
wine & food 120 x 90
WebVitamins Why Pay More?
Subscribe to USA TODAY and get 33% off
Copyright © 2002 Lou Communications, Inc., 4 Central Ave., Albany, NY 12210. All rights reserved.