Some Firefly facts
Fireflies are also called Lightning Bugs. Named as they are nocturnal luminous
insects of the
beetle family Lampyridae, consisting of about 1,900 species that inhabit
tropical and temperate
regions. The common glow worm is a member of this family.
Fireflies are soft bodied beetles which sizes range from 5 to 25 millimetres in
length. On the
underside of the abdomen it have special light organs that glows in luminous
flashes. The
flattened, dark brown or black body is often marked with yellow or orange. Most
of the fireflies
feed on pollen and nectar but for adult fireflies they do not eat.
What bring the sexes together? The female fireflies will produce a short
rhythmic flashes that
attracts the males fireflies. The females will sit on the ground in the high
grass to flash to
certain male only. The female chooses the males based on their flash pattern.
However, others feel that the flashing is not to attract the opposites but as a
mechanism of
warning to advise predators of the fireflies bitter taste. Unfortunately, some
frogs like to eat
them.
How is the firefly light produced? They are produced under a nervous control
within special cells
which are richly supplied with air tubes. Only the light from the visible
spectrum is emitted.
Fireflies do not bite, do not have pincers, do not carry disease and in fact are
quite harmless.
They cannot even fly fast. They have a life span of two months.
http://www.firefly-selangor-msia.com/firefly.htm
Why do fireflies glow?
All known firefly larvae have photic organs and produce light. The behavioral
function of the
larval light has received considerable speculation and several plausible
theories have been
proposed (Lloyd 1971; Sivinski 1981). However, the most generally accepted
hypothesis is firefly
larvae use their luminescence as a warning signal (aposematism) that
communicates to potential
predators that they taste bad because they have defensive chemicals in their
bodies. These larvae
also increase both the intensity and frequency of their glow when disturbed (Sivinski
1981). An
experimental study of whether mice could learn to avoid glowing objects by
associating a
larval-type glow with a bad tasting object further supports the aposematism
hypothesis (Underwood
et al., 1997).
Not all firefly species are bioluminescent as adults, but of the species that
are, one or both
sexes use a species specific flash pattern to attract a member of the opposite
sex (Carlson et
al., 1982; Lloyd 1971; Williams 1917). These bioluminescent signals can take the
form of anything
from a continuous glow, to discrete single flashes, to"flash-trains" composed of
multi-pulsed
flashes (Lloyd 1966; Williams 1917).
In most species of North American fireflies, during a certain time of night,
males fly about
flashing their species specific flash pattern. Females of the same species tend
to be perched on
vegetation, usually near the ground, and if a flashing male catches a female's
fancy, she will
respond at a fixed time delay after the last male's flash. A short flash
dialogue may ensue
between the male and female as the male locates her position and descends to
mate (McDermott
1958). The courtship patterns of Japanese fireflies seem to show many variations
of this type of
communication system, as well as courtship behaviors that include pheromones as
well as photic
signals (Ohba 1983). It is generally assumed that most non-luminous North
American fireflies
locate mates through the use of pheromones.
Aspects of male flash patterns are also thought to be affected by sexual
selection. Female
fireflies have been shown to prefer certain characteristics of a male's photic
signal (such as
increased flash rate) and respond preferentially to males that possess these
"sexy" signal
components (Branham and Greenfield 1996).
http://iris.biosci.ohio-state.edu/projects/FFiles/frfact.html
Copyright 1998 Marc Branham.
Tricky Insects~Fireflies Use Aggressive Mimicry
Aggressive mimicry is a phenomenon where one organism (a mimic) tricks another
organism (the
dupe) into thinking it is another (the model), with the result being a negative
outcome for the
dupe, as well as the model. In the case of aggressive mimicry in fireflies,
mated females that
belong to a few species in the genus Photuris mimic the female responses of
other fireflies in
the same area in order to attract males of the mimicked species. When these
males are tricked (or
duped) into landing near these mimics to mate, they are pounced upon and eaten
(Lloyd 1981)!
Recent evidence also suggests that these female mimics are not only acquiring
food but also
defensive chemicals from their prey, which they themselves do not produce in
large quantities
(Eisner et al. 1997).
Firefly Importance
The light emitted by fireflies is unique. Nearly 100 percent of the energy is
given off as light;
in an electric arc light, only 10 percent of the energy is light and the other
90 percent is
given off as heat. The taillight contains two rare chemicals, luciferin and
luciferase.
Luciferin, a heat resistant substrate, is the source of light; luciferase, an
enzyme, is the
trigger; and oxygen is the fuel. A body chemical, ATP (adenosine triphosphate),
converts to
energy and causes the luciferin-luciferase mixture to light up. Small internal
injections of ATP
in the firefly tail cause flashes of light that can be measured quantitatively.
As all living
cells contain ATP in a rather constant concentration, injection of the firefly's
chemicals
quickly detects energy problems in human cells (different reaction between
normal and cancerous
cells). The firefly technique is used to study heart disease, muscular
dystrophy, urology,
antibiotic testing, waste water treatment, environmental protection and
diagnosis of hypothermia
in swine-a condition costing the pork industry $200 to $300 million each year.
Special electronic
detectors, using firefly chemicals, have been placed in spacecrafts to look for
earth-life forms
in outer space. When as little as one quadrillionth of a gram of ATP enters the
rocket's
detector, a flash of cold light is given off and the signal is recorded by
scientists on earth.
Other detectors warn that milk, food or water may be bacteria contaminated.
Ohio State University Extension Fact Sheet