Friday, April 15, 2011

ID Challenge #1

I always encourage others to send me their photos (or links to their online photos) of odonates that they have trouble identifying. The tougher ones force me to focus on the little details that often go unnoticed and I really enjoy the challenge. Here’s one for you...

Obviously, this image has been altered. It has been converted to black-and-white and I flattened out the mid-tones to obscure any color patterns that would make the identification more obvious. Also the body and basal portions of the wings have been cloaked by a dense fog for the same reason. I boosted the contrast on what’s left to make the wing venation pop out a little better. I cropped out the ends of the right pair of wings in order to enlarge the left pair (there’s nothing over there that you can’t see in the left pair of wings anyway).

This identification is really about the venation, and this individual can be identified to species pretty easily if you know what to look for. This is a fairly common species in the Pacific Northwest, and it is not restricted to this region. I suspect that many readers will not know what it is, but there’s nothing wrong with that. I hope it will be an interesting and educational experience once the answer is posted.

Post a comment with your answer. Even if you’re unsure of the identity, I’d like to hear from you anyway. In about a week, I’ll post a follow-up with the answer. In the mean time I will switch on moderation of all comments, so they will not appear on the blog until I post the answer.

Have fun and good luck!

Postscript, 19 April 2011

This challenge is now closed. The answer with a complete discussion is here.


  1. Jim,

    How about Pachydiplax longipennis - Blue Dasher.

    Nate Kohler
    Deer Lodge, MT

  2. How about Blue Dasher, Pachydiplax longipennis?

  3. Pachydiplax longipennis