Wednesday, June 17, 2015

Blue Dasher Dragonfly

I love to sit on the front porch and watch the dragonflies chase around above the Water Garden.  The Blue Dasher is an abundant and entertaining member of the group.

Males of the species are most noticeable as they perch on vegetation near the water.  They will typically choose the highest point on a plant stalk from which to sit and observe, but when the rushes bend down the dragonflies will take a position on the highest point of the arc.  From this vantage point they will rush out to capture small flying insects or chase away rival males.  There are so many things that need chasing that the males are seldom still for very long.

The females are more secretive and less often seen.  They will perch to watch for suitable insect prey, but they don’t go in for the aerial acrobatics associated with protecting a territory.  That and their more drab coloration, tends to keep them from being noticed.

A female hovering close above the water usually indicates an individual searching for a suitable location to deposit eggs.  The downdraft from her wings produces a pattern of rough water similar to that below a hovering helicopter. 

Egg release occurs when the female dips down and touches the tip of her abdomen to the water.  Several hundred eggs can be released a few at a time in less than a minute.  Each egg will produce an aquatic nymph that will stalk the depths of the Water Garden in search of aquatic prey.

video
This short video shows the female depositing eggs into the water.  The white eggs can be seen falling through the water after each dip of the abdomen.  Click HERE for the higher quality YouTube version of the video.

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