flora
& fauna
A
closer look at Canada's Odonates
Those fascinating dragonflies and damselflies
©Outdoor
Adventure Canada
Anyone that canoes
or hikes in areas where there are numerous ponds
and lakes has met up with dragonflies or damselflies.
My first experiences with these creatures were
as a child. I remember sitting at the edge of
the pond with my Dad watching the "helicopters"
and how fascinated I was with them.
Dragonflies and
damselflies are part of an order of insects
that is over 300 million years old, odonata.
There are more than 5000 members of the Odonata
order throughout the world and many of these
can be found in Canada. There are 85 recorded
species and 9 families of odonata in Algonquin
Park alone.
What
is the difference between dragonflies and damselflies?
Well the most prominent difference is the wings.
Dragonflies are from a suborder named anisoptera
and their wings are horizontal and at a right
angle to insect's body. Anisoptera fully open
their wings. The suborder zygoptera or damselflies
hold their wings behind their bodies and they
only open their wings part way. The pattern
that is visible on the wings is actually the
veins of that makes the wings fast and strong.
Dragonflies can even fly in reverse and move
each wing independently from the others. Damselflies
are generally smaller than Dragonflies and the
eyes of a damselfly are set wider apart. Both
have enormous compound eyes which allow them
to easily see their prey and the Odonates also
have three regular eyes.
Both suborders are
predacious and they feed on other insects which
they catch with their legs. Odonates use their
legs like little baskets to scoop their prey.
Once we were at the Cascades near Algonquin
Park's Barron Canyon on a campsite that was
basically a large clearing. Much to our delight
we were bombarded with dragonflies who voraciously
ate up all the mosquitoes on our site. This
all took place at dusk and it was somewhat surreal.
We actually had to sit down to avoid the activity
in the air.
The life cycle of
a dragonfly varies from species to species.
In its naiad form a dragonfly or damselfly can
live anywhere from months to a few years in
the water. Habitats range from rivers to ponds
and even bogs. Odonates eat water dwelling insects.
Dragonfly naiads have even been known to eat
the odd tadpole. They shed their naiad shell
and sit for many hours waiting for their bodies
to expand. Blood flows into the wings and during
this stage they are in great danger of being
eaten by frogs and other creatures. Ironically
odonates eat tadpoles as naiads then risk being
devoured by frogs later in their life cycle.
During mating the
males seek out the females. The two bodies form
a contorted heart shape and the male transfers
his sperm from his genitals at the abdomen to
his secondary sex organs. The male has claspers
at the end of his tail. He uses these to grab
the female behind the neck and she will bring
herself up to his secondary sex organs and transfer
begins. If accepted the male will transfer his
sperm to the female. Some males will even scoop
out sperm deposited by a previous male. It is
quite an acrobatic feat. The male protects the
female while she deposits her eggs in the water
and wards off other males.
Often you will see
dragonflies and damselflies in sunnier conditions
except for the Fawn Darner which is more prominent
on overcast days or at dusk.
One
of my favourite odonates is the Ebony Jewelwing.
This Damselfly has a metallic body and dramatic
black wings and is found near streams and rivers.
Dragonflies such as the Canada Darner and the
Common Green Darner have spectacular colourations.
The Common Green Darner is one of the largest
dragonflies in Canada.
Even as an adult
I'm still captivated with these creatures. In
May of 2004 I had the opportunity to watch the
emergence of what I believe to be Uhler's Sunfliers.
It was incredible to see the naiad exit his
outer body and spread his wings for the first
time.
Written
by Laurie March
Dragonfly and Damselfly photos by Laurie March