Earwig: Wing Unfolding

NikonUser · Post by **NikonUser** » Mon Sep 28, 2009 9:48 am

Best description I could come up with; disclaimer - read at your own risk

#1: female with forewings (elytra) removed
#2: 1st unfolding; what I'm calling LW (lower part of wing) has been pulled out from beneath the upper part. Very 3-dimensional, looks like an inverted V when vieved from the front with the fold line at top of inversion.
#3: moving the upper part of the wing at right angles to the thorax cause it to partially rotate ventrally, the lower part of the wing now becomes the major part of the dorsal surface. There is another layer of pleated membrane beneath the LW and it unfolds from a ventral hinge H.
The ventral part A rotates outwards at the point where the pin is holding the wing at right angles to the thorax, see #4.
#4: When A rotates outwards the upper part of the wing that had rotated ventrally now rotates back dorsally and the hinge H is now about half way between labels A and C. The pleated wing membrane (B & C in #3) is now greatly expanded.
This image is again 3-dimensional, all the lower part of the membrane below the dotted red line is laying flat and all the part above the red line is almost vertical.
#5: Moving part C (in #3) forward results in the unfolding of more membrane.

D is just for reference

Earwigs must be some sort of contortionists to unfold their wings, and some sort of packing expert to fold them up again.

#5 has been flattened and floated in alcohol onto a microscope slide; accounts for the odd colours

NU09185

Graham46 · Post by **Graham46** » Mon Sep 28, 2009 11:03 am

Amazing work! Looks like a lot of effort went into this, great job.

rjlittlefield · Post by **rjlittlefield** » Mon Sep 28, 2009 11:45 am

Amazing work, indeed!

I was hoping that somebody else would do this before I felt compelled to try, because I know how very difficult and time-consuming it is to pull off something like this.

To see the mechanism described and illustrated so clearly is a huge treat for me!

I suspect it will also become a standard reference for years in the future.

Nice, very nice...

--Rik

Graham Stabler · Post by **Graham Stabler** » Thu Oct 01, 2009 4:27 am

That's really great stuff, the manipulation would be hard enough without having to record each step so nicely.

I have a paper about this if you are interested, it also has some pretty neat photos but nothing like this.

Graham

NikonUser · Post by **NikonUser** » Thu Oct 01, 2009 6:53 am

If I had known Rik was going to do it I would have held off.

The paper would be an interesting read, nice to know if my description was close to what actually occurs.

lauriek · Post by **lauriek** » Thu Oct 01, 2009 8:57 am

Nice work NU!

The only thing missing is a picture of the whole earwig with the wing extended, I don't suppose you have one of those do you? (For proof to the unbelievers that these do in fact have wings!)

Harold Gough · Post by **Harold Gough** » Thu Oct 01, 2009 8:59 am

Amazing series.

Perhaps they are thigmotropic to avoid having to go through all this!

Harold

NikonUser · Post by **NikonUser** » Thu Oct 01, 2009 11:51 am

Graham Stabler wrote: I have a paper about this if you are interested, it also has some pretty neat photos but nothing like this.
Graham

Graham:
I received your PM and replied positively. However, the message is in my Outbox and I can see no way to send it- it may have been sent but it does not show in the Sent box.

EDIT: Rik say's it went, so deleted my e-mail address.

rjlittlefield · Post by **rjlittlefield** » Thu Oct 01, 2009 12:36 pm

It's been sent. Messages appear in the sender's Outbox until the recipient reads them. Then on the sender's side, they magically migrate to Sentbox. Think of it as a somewhat bizarre form of read receipt.

--Rik