Identifying the Blue Dasher Dragonfly

Blue Dasher dragonfly at Schuylkill Center - Photo by Donna L. Long
Blue Dasher dragonfly (male) at Schuylkill Center – Photo by Donna L. Long

I am sure I saw a cartoon with an animated dragonfly as a fighter pilot. It must have been one of those “old-timey” Popeye era ones. Since then, I have been fascinated by dragonflies.

I don’t know if it is their wickedly cool body design or their piloting skills. Probably, it’s both. Just look at some of these photos.

Identifying the Blue Dasher

The males and the females look quite different. It is the males who have the black-tipped blue abdomens, white faces and metallic green eyes. Females and immature males have brown thoraxes with yellow stripes and reddish-brown eyes.

This is a Blue Dasher (Pachydiplax longipennis) dragonfly. Apparently, “longipennis” means “long-winged”. Thank goodness. The Blue Dasher is also called the Blue Pirate. This species is abundant across much of North America. It is classified as a member of the Skipper family.

A Dragonfly’s Wings

The intricate delicate wings are engineering marvels. Not only can they beat up and down, but all four wings can move independently. The wings can also rotate like an airplane propeller. Dragonflies can fly up, down, backwards, forwards and hover in mid air.

Sometimes the markings on the wings are useful in identifying species.


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Male Blue Dasher dragonfly at Schuylkill Center – Photo by Donna L. Long

What do Blue Dashers do?

The males have a favorite perch which serves as their headquarters. From this perch, the males periodically fly over the pond and chase other males.  The males spend much of their time chasing each other and displaying their blue abdomens.

This male (known by the blue color of the abdomen) is perching on a plant stalk overlooking a pond. Blue Dashers  display behavior called perching. Perchers, in the dragonfly world, perch horizontally on shoreline shrubs and vegetation, many times high up from the ground. Perchers make brief flights at low (under six feet) heights over their territory. Which is exactly what this dragonfly did. Other dragonflies are “fliers” which spend long periods flying, not perching.


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Blue Dasher (Pachydiplax longipennis) nymph.


How long do they live?

Adult dragonflies can live several years. In the larval stage they can live in the water up to two years after hatching. The female dragonfly lays her eggs underwater.


What do they eat?

Dragonflies are voracious eaters who are know to eat up to 10% of the body weight each day. Both the aquatic larvae and winged adults are predators who eat other flying insects. Most of their prey is smaller than they are such as tiny flies, leafhoppers, beetles, ants, moths, butterflies, etc. The large dragonflies, such as the Blue Dasher, may eat other dragonflies or damselflies.

Where do Blue Dashers live?

I spotted many Blue Dashers around a body of standing water (a pond in this case) with some vegetation. If water doesn’t have some vegetation, Blue Dashers are unlikely to be there.

Fun Facts about Dragonfly Nymphs

This is a dragonfly nymph. Dragonflies have a three-part life cycle of egg, larva (nymph) and adult. They go through metamorphosis much like other insects. When a dragonfly nymph is fully growth it climbs up a stalk, out of the water and the adult form emerges.

Dragonflies breathe through gills in their rectum. The rear end of a dragonfly functions as an extraction machine which separates oxygen from the water so the dragonfly can breathe. I think the expelling of the water is what also gives the rectum functions as jet propulsion underwater. The dragonfly must shoot water out of the rectum which creates the jet propulsion underwater. The rectum is also the end of the digestive track and performs the usually waste disposal actions. In the book Dragonflies and Damselflies of the East, Dennis Paulson calls the nymph rectum a “multipurpose organ” and a “miraculous rectum”.

Female Blue Dasher. Credit: Eugene Zelenko, CC BY-SA 4.0.

They migrate… we think

The Blue Dasher is one of the species of dragonflies that appears to migrate. I say appears to migrate because large populations of Blue Dashers are seen in midsummer along the Atlantic Coast. No one knows where they go.


I spent an hour watching dragonfly behavior at the pond. It was hot but I was fascinated. Since Blue Dasher are among the most common and abundant dragonflies in North America, you are bound to see one.

August is the time I see the most dragonflies. I have notice many dragonflies zooming through the air in mid-August through September. THey are going somewhere, we just don’t know where.


More on Dragonflies

Migrating Dragonflies

Dragonflies of Philadelphia: A Checklist

Common Green Darner


Books on Dragonflies on My Bookshelf

These links are affiliate links. I may earn a commission for Amazon purchases using the links. This does not affect the price you pay.

Dragonflies and Damselflies of the East (Princeton Field Guides) by Dennis Paulson. Princeton: Princeton University Press, 2011.

Dragonflies and Damselflies of the West (Princeton Field Guides) by Dennis Paulson. Princeton University Press, 2009.

Stokes Beginner’s Guide to Dragonflies by Blair Nikula, Jacke Sones, and Donald and Lillian Stokes, covers over 100 common species of dragonflies and damselflies. Boston: Little, Brown and Company, 2002.

Dragonflies & Damselflies: An Introduction to Familiar, Widespread North American Species (North American Nature Guides) by James Kavanagh. Waterford Press, 2000.


  1. I have just written a Children’s Book about the Blue Dasher Dragonfly. Thanks for the info as it
    helped me with the story line!


  2. How very interesting!!! I really enjoyed getting to know this dragonfly through your blog. It does make me wonder if they migrate like the birds or maybe like some butterflies, overwinter under bark or rolled up in leaf litter.

    • Hi, Heidi

      Thanks for the comment. The extraordinary lives of dragonflies proves to me that no matter how much humans think we know, we really don’t know very much at all. It keeps me humble.

  3. I like the picture of the one with the broken wing. Seeing beat up butterflies and other insects always makes me wonder what they have been through and where they have been. Also, great shot of the nymph stage! Keep up the good work!
    Sean at

    • Hi, Sean

      I like seeing butterflies and dragonflies who are a bit bedraggled. The look as if they have led interesting and action-filled lives. Much like human beings.

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