Thursday, October 14, 2010

Watching "Mosquito Hawks" at the Constructed Wetland

As they peered through their reliable binocular lenses, they watched the
defenders of the pond put on a show of aerial acrobatics.  John and
Jeannette Murray have been identifying the different species of
dragonflies and damselflies that have moved into the newly constructed
wetland in Boone this summer.  The couple have been regular visitors to
the wetland and said they enjoy unwinding with a stroll around the ponds
observing the hovering, spinning, fascinating show the insects choreograph. 
Since July 2010, they have counted 15 species of dragonflies and 5 species
of damselflies.  (see below for list of species names)

You may be wondering how to tell the difference between a dragonfly and
damselfly?  The best way is to look at their wings when they are at rest.
Typically dragonflies keep their wings out to the sides flat at rest. 
Damselflies have most of the same body parts as dragonflies but keep their
wings closed above their body when at rest.  The damselfly is also a
predator but they typically aren't as fierce and quick as the dragonfly.

Observing this many species at the wetland is a wonderful sign, it exhibits
a thriving ecosystem.  The dragonflies are sometimes referred to as
"mosquito hawks" because of the amount of pesky mosquitoes they consume. 
Some species mouths are big enough to devour mosquitoes in mid flight,
while others will catch their prey mid flight and fly to a leaf to eat.
Not to worry because rarely are their mouths big enough to bite humans.

One of the most interesting aspects of these insects is the way they spend
the first part of their lives.  Female adults will lay eggs in water
edges, wet plant material, and depending on species they will hatch
anywhere from a few weeks to a few seasons.  Once the larvae is in the
water they swim and hide and wait for prey to swim by.  Throughout spring,
summer, and fall, exuvia can be found lingering on plant stems which is
the leftover exoskeleton that is left behind after the larvae splits and
the adult pushes itself free.

The numbers of dragonflies and damselflies are starting to dwindle with the
cooler temperatures this fall, we are all looking forward to observing these daring 
stunt fliers in 2011. If you are interested in learning more about these 
captivating insects, a guide book has recently been produced by Giff Beaton, 
Dragonflies and Damselflies of Georgia and the Southeast.   
List of Odonates found at the wetland Summer 2010 (thank you to 
John and Jeannette Murray for the list compilation)

Common Whitetail
Widow Skimmer
Eastern Amberwing
Twelve Spotted Skimmer
Golden Winged Skimmer
Eastern Pondhawk
Common Green Darner
Blue Dasher
Slaty Skimmer
Swamp Darner
Wandering Glider
Black Saddlebags
Autumn Meadowhawk

Ebony Jewelwing
Familial Bluet
Blue Fronted Dancer
Powdered Dancer
Eastern Forktail

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