Fireflies are the source of much interest
by Christine Yesko
I remember when I was a small child running around my backyard in the early evening, chasing those “lightning bugs”, putting them in a glass jar admiring their blinking lights. I haven’t seen them in a long time until just recently.
What a pleasant surprise, although the “firefly” is not really a fly at all. It is a beetle in the family Lampyridae that, along with several hundred other closely related to firefly species, has the remarkable ability, in all of its life stages, to biologically generate light.
The adult beetle, which is the form most familiar to people, is 1/2 to 3/4 inch in length, with a flattened body that is black in color with yellow highlights and prominent red spots on the back of its thorax. It has large eyes and long antennae and flies in a gentle, hovering manner. The light-generating parts of these adults are in the terminal segments of their abdomens. The adult firefly has long, curved mandibles that suggest a predaceous lifestyle, but only a few species have been known to actually consume anything other than flower nectar or pollen.
The less well-known larvae of the firefly, called “glow worms”, live in leaf litter and are voracious predators. They eat other insects, mites, earthworms, and even slugs and snails. The lights of the fireflies represent communication mechanisms.
The female perch on the vegetation and generate a specific sequence of light flashes that attract the more mobile males. The male responds with an answering light sequence and zeros in on the females in order to mate. After mating, the females lay their eggs on the surfaces of woody or leaf debris. The eggs hatch in a few weeks and emerging larvae burrow into soil/litter habitat where they feed on a wide range of invertebrates and overwinter there.
In the spring, they re-emerge and continue to feed. After a few weeks, they re-enter the soil and pupate. Then they emerge from their chambers in early to mid-summer as adult fireflies.
The mechanism for the production of light in fireflies is mediated by the enzyme “luciferase”. High energy phosphates generated from food molecules are coupled via luciferase to the direct production of photons of light. This coupling is extremely efficient (90%) and generates almost no waste energy. The genes that regulate this light generation have been used in cancer research to mark and track metalizing cancerous cells.
The widespread use of pesticides and herbicides is the cause of declining numbers of fireflies throughout North America. It is hoped that this decline can be reversed so that we can all continue to have the pleasure of observing these unique and wonderful organisms.
Information obtained from Penn State University, enjoy the weather.
