Flies have amazing control over their wings. They can rotate them on the long axis, which is what I think we're seeing in this photo.

For example, see "Grooming," on this page, a short movie of a fly grooming on my finger. You can see the fly rotate a wing about 90 degrees.

For real movies of fly wing motility, check out Michael Dickinson's research on fly flying. An example is this NPR story, which includes movies.

Given wing movement and the way they rotate their heads, flies can get squeaky clean! What blows me away is reversing wings in flight. Maybe that's the advantage of having just two? (I've read that 80% of a dragonfly's muscles are devoted to flying, but have never seen them pull off anything like this.)

Reminds me of a helicopter's blades. BTW Stephen, I concur with Ron. This has been an enlightning learning expeerience. Thanks for sharing.

I understand (vaguely) that it's part and parcel of fly flying. Here's a bit from the abstract of one of Dickinson's papers:

"In addition to contributing to the lift required to keep an insect aloft, these two rotational mechanisms provide a potent means by which the animal can modulate the direction and magnitude of flight forces during steering maneuvers."

As syrphids hover, and move in all three dimensions while hovering, maybe it's not surprising that they'd have extremely rotatable wings.

The ultra-high-speed digital movie cameras are incredible. But it's amazing what you can get with just the QuickTime movies captured with a point-and-shoot like my Nikon Coolpix S10. It's fairly easy to create slow motion or image sequences from short clips. Some of the newer video/still cameras may be great too, like the Sanyo Xacto HD2.

This is an amazing shot, by the way. My best syrphid-in-flight stills just show blurs.

However, I was sorta hoping I could apply for a grant to find out :)

Contact Michael Dickinson at CalTech. He's a former MacArthur genius award winner, and has a full lab. He may still have slots for grad students!

If you want to be an independent researcher, I think you need one of those 1,000 fps digital movie cameras.

I wondered about that one, too. The wings look as if it was doing the backstroke. It is interesting. see another angle http://bugguide.net/node/view/233887