Threat Display

Common Whitetail Skimmer (photo by Chuck Tague)
Male Common Whitetail Skimmer (photo by Chuck Tague)

This dragonfly doesn’t perch like this for fun.  His pose is a threat display.

This is a male Common Whitetail (Plathemis lydia), a showy dragonfly with a white pruinose abdomen and clear black-striped wings.

Common Whitetail males are highly territorial.  They live near ponds, marshes and slow moving rivers where they defend 10 to 30 yards of the water’s edge and conspicuously chase away all other males.  When they’re not chasing or fighting they pose like this to let rivals know they mean business.

Their white pruinose backs are the warning sign.  Pruinose refers to the dusty, frosted appearance caused by a pigment that covers the insect’s “skin.”  In nature, pale-colored pruinescence often reflects ultraviolet light.  Perhaps this bug glows in sunlight.  I wish I could see it!

Female Common Whitetails look quite different because their tails aren’t white, a feature that probably protects them from male aggression.

Look for males patrolling and chasing at the water’s edge.  Find females nearby, choosing mates and looking for places to lay their eggs.

Female common whitetail dragonfly (photo from Wikimedia Commons)
Female common whitetail dragonfly (photo from Wikimedia Commons)

These dragonflies are good bugs to have around. They eat mosquitoes.


(photo of male by Chuck Tague, photo of female from Wikimedia Commons; click on the image to see the original)

6 thoughts on “Threat Display

  1. They have a bunch of these at Beechwood Farms in Fox Chapel … gorgeous … and very nonchalant with humans

  2. See quite a few of these at Crooked Creek on both ponds. Also a few Pond Hawks and Spangled Dashers, and other neat Odonata…interesting article, Kate–thanks, I did not realize the reasoning for this “pose/perch”. I have seen the females and it their bodies resemble a dagger or lance or other weapon, in a way, in my opinion.

  3. I used to see one a lot last summer, patrolling by Schenley Park swimming pool. Maybe he thought it was a pond?

  4. near our very small pond. long slilm white body dark, (black) wings , the wings look like dadrk paddles as part of them are transparent…..????

  5. Today I took half an hour to catch a few pictures of the male. It was beautiful while it roamed threw our vegetable gardens 🙂 there is a huge saloo about half a mile west of us and a few small ponds about a mile north of us.

  6. Hey!

    I have a few of these outside my apartment. We have water features here so the water territory makes sense. They are so beautiful, that I finally looked them up, very cool!!

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