Moab Happenings Archive
Return to home

NATURE HAPPENINGS - July 2007

Of Damsels and Dragons
by Damian Fagan

Summer is the time for damsels and dragons, but I don’t mean those in distress or the fire-breathing kind. No, I mean damselflies and dragonflies – winged insects far older than their medieval namesakes.

Both groups of insects are in the order Odonata (meaning “toothed ones”), but they are somewhat different in appearance in both the larval and adult stages. Adult damselflies have similar shaped wings that are folded over their bodies when at rest (except for the spread-winged damselfly) and dragonflies hold their wings out at rest. A dragonfly’s hind wing is broader at the base than the front wing, and they are much stronger fliers than damselflies. Also, the large eyes of a dragonfly meet at a seam in the back of the head. These wraparound eyes contain over 30,000 lenses and provide a 360-degree field of view.

Damselflies have eyes that are spread further apart, much like those on a hammerhead shark.

In their aquatic larval stage, damselflies are more streamlined and sport 3 projections on their tail end. These leaflike structures are gills. Dragonfly larvae are more compact and heavier than their relatives are. They keep their gills inside their abdomen, located just inside their butts. When pursued by prey the dragonfly larvae squirts water out their backside, moving them along by jet propulsion. Damselflies crawl along the bottom or squiggle through the water.

To mosquitoes it doesn’t matter the life stage of either insect, for damselflies and dragonflies, in particular, prey upon both the larval and adult “skeeters.” An adult dragonfly consumes about 300 mosquitoes a day. Damselflies feed more on aphids, young grasshoppers, and other insects, as well as mosquitoes.

Though highly beneficial, dragonflies were once considered “snake doctors” and “devil’s darning needles” because of their ancestral appearance. Folk people thought the long hind end of a dragonfly contained a stinger, capable of injecting poison. But this appendage is like a tow-truck grappling hook on the males and an egg-depositor on the females.

When breeding, a male damsel or dragonfly will use their grappling hook like tip to lock onto a female’s head as she deposits her eggs in the water. The pair resembles a glider and tow plane. Both lay their eggs in water and their larval stages are fierce aquatic predators.

Both have a lower lip or labium that folds under the chin when not in use. When prey swim into range, the lip quickly projects outwards and snags the creature. It is pretty interesting to watch damselfly larvae slowly turning about in the water while they focus on their prey. They are like aquatic cats, waiting to pounce.

When the larvae are ready for adulthood, they emerge from the water and crawl up onto the ground or nearby vegetation. Their skin splits down from the head and out comes the adult. Until their wings and body segments dry and harden, these adults are vulnerable to predators such as birds, frogs or snakes. Once airborne, dragonflies may fly up to 35 m.p.h. and they can fly backwards, stop abruptly in midair and hover like a helicopter.

These ancient aerialists have a long history on the Earth – some 325 million years. Fossil records indicate that these insects were once the size of crows. Imagine the size of prey they must have eaten! It gives new meaning to the concept of an insect bite.
So during July, when you are seeking the cooler retreats along canyon streams or higher elevation pools take a few moments to see if there are any damsels or dragons lurking beneath the surface or lording over the air. I think you’ll enjoy their antics and appreciate their hearty appetites.

 

 

 

 

Return to Archive Index
 
Return to home

info@moabhappenings.com