Pachydiplax longipennis (Blue Dasher) ♀.
 
 
 
Size: approx. 40 mm. Photo: 07/19/11, 10 am.


Another dragonfly: a female blue dasher Pachydiplax longipennis. This one is a skimmer. Below is a close-up of the face (left photo) and another specimen (right photo). 
 

  

A short video is available on my YouTube channel.
 
bug guide (this photo):
http://bugguide.net/node/view/548310


Pachydiplax longipennis (Blue Dasher) ♂.
 
 
 
Size: approx. 30-40 mm. Photo: 07/21/11, 5 pm.


As for many other dragonflies, the males look quite different. This here is a male blue dasher Pachydiplax longipennis. The mature male is completely (powdery) blue. The bug guide refers to this stage (half-jokingly) as "tweens". 
 

A short video is available on my YouTube channel.
 
bug guide:
http://bugguide.net/node/view/598