
This is, of course, a cherry. But as you've probably already guessed, I'm not very interested in the cherry.
No, this time I'm interested in that small lesion on the side of the cherry, about half way up the left side.
That's actually a hole, extending from the outside of the cherry clear into a void that has formed next to the pit.
It's the access portal, if you will, into the world of the Western Cherry Fruit Fly, Rhagoletis indifferens.
You might want to stop at this point and review my 2008 posting about this beast. There, I looked closely at the ovipositor of the adult.
This time, it's the larvae that have captured my attention.
More precisely, the front end of the larvae, the mouthparts mostly. What prompted my interest is that while sorting and cleaning some cherries, one of the maggots happened to get on my finger and make a run for safety. The sensation was quite strange: "Say what?! Maggots are scratchy??"
On closer inspection, I figured out what was going on.
Turns out, fruit fly maggots have fangs! Well, officially they're called "mouth hooks", but they could just as well be fangs.
Here, see what I mean:

As far as I can tell, these mouth hooks are multifunction tools, good both for locomotion and for shredding the flesh of the cherry.
When the larvae want to move fast, they stop squirming and start lunging, repeatedly thrusting the head forward, sinking the mouth hooks into whatever's handy, then pulling their head back to pull the rest of the body forward. It's very effective.
I wanted to shoot a movie of the action, but that would have required far more skill than I have. So instead I decided to "make do" by just shooting a bunch of stills.
Here's a montage of the few acceptable shots I got. You can tell from the image numbers that there were a lot of duds too.

As usual, I find that the structure of the beast is more richly conveyed in stereo. This is crossed eye, and I've tried to avoid window violations for those of you who are sensitive to that.

The fan-shaped structure at the top of the image is one of the two anterior spiracles. They feed large tracheae that run back along the body of the larva, with smaller tracheae branching off those to provide oxygen to the rest of the body. You can see many of these under the skin, in the nearly transparent outer portions of the body.
Here's one more stereo, a different specimen showing the same structures. This one gives a little better view of how deep inside the head the sclerotized portions extend.

The high mag images are shot with Mitutoyo 10X on Raynox 150 tube lens, Canon T1i camera, illumination with diffused Jansjo LED lamps, mostly directed at a piece of white card under the specimen, with a small black card held in place as a partial darkfield stop. Vertical setup, shot through a thin layer of water with the specimen stuck into a drop of sticky water-soluble transparent "personal lubricant". I'll post pictures of the setup separately (HERE).
I hope you find this interesting!
--Rik
Edit: add link to pictures of the setup