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As a child I lived in the Ozarks in Missouri,
and one of my earliest summer memories is of having a firefly in a jar next
to my bed. I was thrilled to see them again during a summer visit to Virginia.
But I had read that fireflies are never seen west of Kansas, so I never
looked for them here.
Then one night, while gazing out at our meadow at dusk,
I saw a twinkling light, and blinked to be sure I hadn’t imagined
it. I had fireflies in my front yard in Bayfield!
According to Whitney Cranshaw, Colorado State University
Entomologist, light emitting fireflies (not all adult fireflies produce
light) have never been common in the western United States, although they
do occur in scattered pockets around Colorado. They are almost always found
near streams and permanent wetlands that have not been overly damaged by
human activity.
Fireflies, or lightning bugs, as they are more commonly
called in the south, are not flies at all, but beetles. Fireflies are typically
less than an inch long, and rather soft bodied for a beetle. The last two
segments of their abdomen is normally lighter colored and this is the part
that glows or flashes at dusk. The larvae, which can remain in the soil
for up to two years eating ground dwelling insects, are called gloworms,
because they too luminesce.
What’s all this flashing about? Women of course.
The male firefly flashes a distinct pattern in an effort to attract a mate,
and the female, when receptive, will flash a response. Some species of female
are known to imitate a different species pattern to attract males for an
evening meal. Except he’s the entree! Firefly species are often identified
by their flash patterns, and entomologists use a pen light to mimic the
pattern when they want to catch them.
The luciferase chemical reaction going on inside these
insects has been used by scientists for years. Once scientists understood
the process, which uses ATP, an energy source in the cells of all living
things, as part of its reaction, they started to use it in many forms of
research, including cellular biology, genetics and even the search for life
in outer space. If it glows, ATP must be present. But until recently, the
only way to obtain luciferase was to harvest it from fireflies!
Recently, scientists were able to isolate the gene responsible
for creating luciferase, thus enabling a pure form to be grown in the lab.
We no longer need to harvest fireflies for their light producing chemicals.
So if you see a flash at dusk, your eyes don’t deceive
you. But adult fireflies only live a few short weeks, so enjoy them while
you can.
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