Firefly Light

(This column appeared in the April 7, 1997 Buffalo News.)

     In The Duchess of Malfi the Elizabethan dramatist John Webster wrote:

Glories, like glow-worms, afar off shine bright,
But look'd too near have neither heat nor light.

Written almost 300 years ago, those lines reveal more than their author's command of metaphor. They show keen observational skill as well.

     Glowworm is the name commonly assigned to the larvae of fireflies or light ningbugs. (Interestingly all three are misnomers as fireflies are neither worms nor flies nor bugs; they are beetles.) The term glowworm is more commonly used in Europe where these insects patrol gardens above ground seeking slugs and other prey. In North America most of the larvae of our 50 firefly species live in the soil where they feed on earthworms and millipedes. Only occasional floods force them to bring their dimly shining light to the surface. Thus we usually see only adult male lightningbugs winking on and off as they fly in search of the females who occasionally blink in response from their grassy hiding places below.

What Webster so astutely observed is the cold light produced by these insects, a kind of illumination also emitted by a wide range of bacteria, protozoa, fungi, sponges, crustaceans, fish and lower plants as well. Unlike the average electric light bulb that loses about nine-tenths of its energy to heat, this "living" light creates virtually no warmth.

T oday chemists are already applying and studying further applications of the fireflies' tools, their light-generating luciferin molecules and luciferase enzymes, to a wide range of problems. Here are a few:

Obviously these are highly significant applications of substances found in fireflies. Today major chemical companies in the United States, Russia and J apan supply them. But there is a difficulty. Many fireflies are collected and killed in order to obtain these ingredients. One mid-western company has formed its own Firefly Scientists' Club whose members are paid for each firefly captured. The numbers ha ve been extraordinary. A single Iowa woman has netted millions of fireflies for this purpose. Even that level of mass-harvesting appears not to have made a serious dent in the populations of our common fireflies, but entomologists worry about the possible inadvertant extinction of rarer species in the process.

At least one solution appears to be available, however. Scientists have cloned the gene for firefly luciferase and it is now created by bacterial cultures in commercial laboratories. We can only hope that such alternate means of producing these valuable substances will be universally implemented before we doom another of our fellow travelers on Planet Earth.

How sad it would be to lose any one of these little beetle species that so delight us on summer nights -- and to eliminate it because it serves us scientifically as well.


Footnote: In Japan there is much more interest in fireflies as Ron McCluskey (rmcclsky@televar.com) found out. He lists the following sites, but notes that most of them are in Japanese language. Readers seeking further information about fireflies, however, might well check out some of them. I have found some excellent information on such foreign postings even though I did not understand the language. Here are McCluskey's references: Japanese Firefly 1, Japanese Firefly 2, Japanese Firefly 3, Japanese Firefly 4, Japanese Firefly 5, Japanese Firefly 6, Japanese Firefly 7, Japanese Firefly 8, Japanese Firefly 9, Japanese Firefly 10, Japanese Firefly 11, Japanese Firefly 12, Japanese Firefly 13, Japanese Firefly 14, Japanese Firefly 15, Japanese Firefly 16, Japanese Firefly 17, Japanese Firefly 18, Japanese Firefly 19, Japanese Firefly 20, Japanese Firefly 21, Japanese Firefly 22, Japanese Firefly 23, Japanese Firefly 24