Saturday, 4 October 2008

Major miner

Instead of doing the work I was supposed to do, I went out again with the camera to see if I could pin down the mysterious miner.

Success! I found a pupa tucked away at the end of a tunnel. Turns out that the miner is a fly, probably Chromatomyia syngenesiae (Agromyzidae) (a.k.a. Phytomyza syngenesiae). This species is widespread and occurs most frequently on sow thistle (Sonchus oleraceus) — exactly where I found it.

Pupa in its mine. Only the spiracles (respiratory structure) project through the cuticle.

Pupa removed from its mine. The spiracles are visible to the lower left.
There's a maggot feeding away in its mine at the top right.

At least, it was, until it was evicted. That's the head to the right, in case you couldn't tell.

The mines exposed to reveal a maggot's waste disposal system.
It's okay when you're always on the move.

7 comments:

Anonymous said...

I hope no maggots died in the production of this article.

Snail said...

Of course not. They were all successfully rehoused. Now, I've just got to check on the ...

sound of footsteps disappearing down corridor, followed by slamming car door and squeal of tyres

Denis Wilson said...

Great study of the Leaf Miners.
I was expecting Noisy Miners (birds).
Denis

Snail said...

I didn't even think of that! You don't see them much around here.

AYDIN ÖRSTAN said...

How does the fly get out of the tunnel?

Snail said...

Darn it, Aydin! You ask the good questions. I don't know. I wonder if it uses the ptilinum to split the cuticle as well as the puparium?

For non-invertebratologists: flies have a bladder-like ptilinum that they inflate when they're about to emerge from the puparium. It pushes open the front end of the puparium so the fly can get out of the case. Maybe this also increases pressure inside the mine and rips the cuticle. I guess the pupating 'chamber' is blocked at one end by plant cells and at the other by the fly's backside. Hmmm ... Time to visit the library.

Sherrie Y said...

Not only all THAT, but your photos rival many a painting I've seen on gallery walls. The last one in the series in particular is a thing of absolute beauty. I want it on my computer as 20" wallpaper. Can I can I huh?