These remarkable insects have the most efficient light in the world. Their “cold light” consists of the luciferase enzyme which acts on the luciferin in the presence of magnesium, ATP, and oxygen. The adults flash to speak with each other and to find mates. Even firefly eggs and larvae glow, as a warning to predators. They tell predators that they taste lousy.
Found on nearly every continent, fireflies are classified as Lampyridae in the Winged Beetle Order of Coleoptera. Scientists usually divide the thousands of species of fireflies into five groups (although these groupings are in a state of flux). Found in North America, the Lampyridinae synchronize their flashes. The Photurinae are known for the females eating the males. The largest group, the Luciolinae live in the Eastern Hemisphere. These fireflies flash instead of continuously glowing. The most primitive fireflies are called the Cyphonocerinae. The “catch-all” group of Lampyrinae have all the fireflies, who do not fit in any of the other groups.
The flashing is done by the adult firefly, who lives only to mate and lay eggs. Meanwhile, the firefly larvae can live for up to two years, eating snails and worms. Some will hibernate over the winter, others for longer. All usually will emerge during warm weather as adults.
Fireflies are disappearing worldwide. Various factors are to blame, most of them created by humans. In developing fields and forests, people have destroyed firefly habitats. The other major problem is light pollution. In many places, lights abound from headlights of cars to porchlights of houses to skylights of malls. All these lights disrupt the flashing patterns of the fireflies, who are trying to mate. (Consult Firefly.org (http://www.firefly.org/) for suggestions on how to help fireflies.)
Watching fireflies at dusk as they flash by recaptures the lost wonder of childhood. As adults, many of us are caught up in our daily activities and concerns. We forget that the world is full of wonder. Fireflies give people pause to see the beauty that is around them. Remember that the firefly is just an ugly bug who twinkles. But twinkle, is what they do well.