Reproduction
Like almost all other animals, the Zigzag
Darner reproduces sexually. Males defend their territory just
like birds, wolves, lions, etc. When a female comes in the
vicinity of other males, the males compete to gain possession of
the female. Competitions like fighting, flight contests, and
threatening displays of patterns of colors on their bodies are
the easiest ways to title the alpha male. When the alpha is
selected the male will grasp onto the female's head and abdomen.
The male will now clasp the back of the female's head. This is
called the tandem position. If the female accepts this advance,
she will tip her abdomen upward to touch the male's genitals to
hers. This position is called the wheel position ("Dragonflies
and Damselflies"). After the male successfully delivers his
sperm to the female, the female usually lays eggs almost
immediately.
As the female is laying her eggs the male Zigzag Darner
is usually perched close by guarding her from other males. The
females usually lay her eggs on grass, close to a shoreline, or
mud. One mating can sometimes supply the female a lifetime of
fertilized eggs. However, if the female mates again with a
different male within about twenty-four hours the first male
would forfeit the eggs to the most current male ("Zigzag Darner-Aeshna sitchensis").
Once the eggs are fertilized one thing the larva have
to worry about before they are adults are mites around their
environment. The mites will latch onto the Zigzag Darner larva
and suck out their juices, killing them. If that doesn't happen,
the Aeshna sitchensis larva undergoes incomplete
metamorphosis. It consists of the egg, larva, and the adult
stage. The Zigzag Darner spends its life majority in the larva
stage. This is when the egg hatches and the larva molts once and
starts to hunt. The larva will molt several times before
developing into an adult.
Once the larva is ready to transform into an adult, the
Zigzag Darner will cling to a surface like a rock, branch, etc
and rest for a short period of time. Once it is ready, the skin
on the dragonfly will crack open and the thorax of the adult
Zigzag Darner emerges. The crack widens allowing the wings, head
and part of the abdomen to emerge. The Zigzag Darner rests again
and that allows the legs to harden. This helps the adult
Aeshna sitchensis to grasp the larva skin and pull him or
herself out ("Dragonflies and
Damselflies"). Now the dragonfly rests again and this allows
the wings to fill with hemolymph. The Zigzag Darner rests for
about an hour letting the wings dry up. Once this happens the
adult Zigzag Darner takes its first flight finding food, mates,
and repeating the cycle again.
(Picture from "Dragonflies and
Damselflies" illustrating the Wheel Position)
Now check out the Adaptation
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