The Cycle of Life
Denise D. Greaves
It was a dark and stormy day. Well,
not really stormy, but the morning was heavily overcast.
That meant there wouldn't be much dragonfly activity,
at least not much that might be noticed to us humans.
Fortunately, by early afternoon it
looked like the skies were clearing, so we took off
to one our favorite places to watch dragonflies—the
pond we refer to as the L
Pond. But by the time we got there, the clouds were
growing darker again. We circled the pond a couple of
times and saw a few dragonflies. But not much was happening,
so we were considering packing it in. By chance, I looked
down among the cattails near the edge of the pond and
gasped at what I saw. We were being treated to a front-row
seat of a demonstration of how green darner dragonflies
(Anax junius) lay their eggs. I snapped several
still shots as I commanded my husband Sheldon to get
the video camera going.
Unlike the typical skimmer, which
scatters her eggs by tapping the surface of the water
with the tip of her abdomen, a female darner has a functional
ovipositor with which she punctures vegetation beneath
the surface of the water and then places an egg in each
puncture. This is done while her mate is still clutching
her following copulation (Fig. 1).
A brief review of dragonfly copulation
will help illustrate the procedure. When dragonflies
mate, the male and female form what is known as a "mating
wheel" and are connected to one another in two places
(Fig. 2). The male attaches the end of his abdomen to
a corresponding fixture in the back of the female's
head, and she attaches the genital segments near the
end of her abdomen to the penis on the male's second
abdominal segment.
After copulation, the female deposits
or distributes the fertilized eggs. In some species,
the female's head remains attached to the end of her
mate's abdomen during this process. That is what is
happening with our green darners in this photo. The
male helps position the female as she lays her eggs.
In this
video made by Sheldon, you can see that she is the one
doing all the visible work.
As Sheldon and I have watched this
process, we have noticed that at times the male pushes
the female almost completely under the water. ("I'll
let you come up and breathe after you lay the eggs,
Dear.") But when she is done, he can pull her out quickly.
On one occasion, we saw a pair of darners suddenly dash
off into flight just as a frog came leaping after them,
its mouth agape. Unfortunately, the video camera wasn't
rolling.
My still camera was the body of an old screw-mount Pentax
SLR equipped with an Asanuma brand 90-230 mm zoom lens.
I used 200 speed Kodak color print film. The video camera
is a Panasonic Model PV-DV 203D palmcorder.
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