All odonates, that is dragonflies and damselflies, have four wings. The following Common Green Darner dragonfly (Anax junius) has a malformed wing: one of its two hind wings didn’t expand to full-size during emergence.
This individual is a male, as indicated by its coloration and terminal appendages. The terminal appendages are shown more clearly in the next photo than the preceding one.
I’ve seen this guy two times during recent visits to a vernal pool at Huntley Meadows Park (HMP). I call him “3.75,” in reference to the number of wings he has. Like other Common Green Darners, “3.75” is able to fly and hawk smaller flying insects; he stops to rest more frequently than other darners, perhaps because he has to work harder to fly than he would if he had four fully-formed wings.
A lot can go wrong when a dragonfly metamorphoses from a larva to an adult. I’m surprised more odonates aren’t malformed, although the ones with fatal flaws probably tend to be uncommon sightings.
Related Resources:
- Malformed odonates, by Walter Sanford
- The Life Cycle of a Dragonfly, British Dragonfly Society
- Odonate Nymphs, by Steve Krotzer, Haysop Hill Photography [larvae are also known as nymphs]
- Odonate Emergence, by Giff Beaton
- Dragonfly metamorphosis going wrong (#423), a YouTube video by nature1upclose
Copyright © 2015 Walter Sanford. All rights reserved.
Tags: Anax junius, Common Green Darner dragonfly, Darner Family, Huntley Meadows Park, male, malformed, terminal appendages, vernal pool, wildlife photography
May 9, 2015 at 8:58 am |
Fascinating post, Walter. I’ll keep my eye open for your friend 3.75. If he rests more often than other Common Green Darners then I might actually have a chance of photographing him (unlike his full-winged brethren, which elude me most of the time).
May 9, 2015 at 11:05 am |
How do you think I was able to get a shot of 3.75, Mike? I noticed he landed in the same spot repeatedly, so I moved into position to be ready for one of his rest stops.