Written By:
Andrew Eide
My topic today is Fireflies.
Before I launch into my article please be advised that fireflies are not flies
at all…they are beetles.
The scientific name for these
beetles we call fireflies is Lampyridae
of the beetle order Coleoptera. They are winged beetles which
are commonly called fireflies or lightning bugs. This is due to their conspicuous
use of bioluminescence to attract mates or prey. Fireflies produce what is
called a “cold light” with no
infrared or ultraviolet frequencies. This light is chemically-produced from the
lower abdomen and the light may be yellow, green, or pale-red, with wavelengths
from 510 to 670 nanometers.
There are about 2,000 species of
fireflies found in temperate
and tropical environments. Many are found in marshes or wet wooded areas. The larvae
of the firefly also emit light and are often called “glowworms.”
The light production of fireflies
is due to a type of chemical reaction called bioluminescence. This process occurs in specialized light-emitting
organs usually on a firefly’s lower abdomen. The enzyme luciferase acts on the
luciferin, in the presence of magnesium ions, ATP, and oxygen to produce light.
The production of light in the
larvae, or glowworms, serves a different function than it does in adult
fireflies. It appears to be a warning signal to predators since many firefly
larvae contain chemicals that are distasteful or toxic.
It was originally thought that the
light produced by adult fireflies was also used as a warning signal but the
primary purpose is now thought to be in selecting a mate. They have various
ways of communicating with their light during courtship including: steady
glows, flashing,
and the use of chemical signals unrelated to the photic systems.
The female of the Photuris fireflies are known to mimic
the mating flashes
of other fireflies for the sole purpose of predation. Target males are
attracted to what they believe is a suitable
mate only to be eaten. This has caused the Photuris
firefly to be referred to as femme fatale fireflies.
I grew up in Oakland, California
in the San Francisco
Bay Area and I don’t remember seeing
fireflies in the Bay Area. I believe I saw a few here and there when we camped
in the mountains but they are not common in this area. When I lived on the East
Coast, both in the States of Virginia and Connecticut,
I remember those nights when I could sit outside and watch the fireflies flit
around and flash their lights. It was a truly
calming and relaxing experience.