Prestomal Teeth revisited (now 4 + 1 images)

NikonUser · Post by **NikonUser** » Wed Mar 28, 2012 8:26 pm

Dave showed a microscope-shot of a Blow-Fly (Family: Calliphoridae) labella (tongue) with prestomal teeth at the base of the pseudotracheae. These teeth although sharply pointed appear weakly sclerotized.
http://www.photomacrography.net/forum/v ... 80cbeced6d

Rik, of course, started the whole discussion about prestomal teeth with his Blow-Fly shots
http://www.photomacrography.net/forum/v ... hp?t=16216

I was photographing the head of a "House-Fly" (Muscina levida) (Family: Muscidae) when I noticed some formidable prestomal teeth.
Top: ventral view of the labella
Bottom: area in yellow circle flattened and rotated to better fit on screen; 10x SPlan Apo + 2.5x relay lens, 16 frames @ 4µ; ZS PMax.
note the heavily sclerotized teeth attached to an equally heavily sclerotized frame that is essentially a jaw.

NU12028 NU12029

NikonUser · Post by **NikonUser** » Thu Mar 29, 2012 12:13 pm

I took a look at one of those large central teeth; 20x SPlan Apo + 2.5x relay lens, 17 frames @ 1µ. ZS PMax.

They are dagger-like with smooth edges; function unknown.

NU12030

lauriek · Post by **lauriek** » Thu Mar 29, 2012 12:29 pm

Whoa! So house flies can bite?!?! (Sorry for being slightly facetious but at that magnification those teeth look fierce!)

This whole discussion is a bit above my head but I appreciate the photography it's bringing about!

discomorphella · Post by **discomorphella** » Thu Mar 29, 2012 5:03 pm

Yeah, I didn't imagine that houseflies had such impressive dentition. The micrographs are so detailed they make the housefly out to be a bigger threat than it is, or rather, I hope the micrographs do that; the alternative is somewhat disconcerting...Great shots.

David

curt0909 · Post by **curt0909** » Thu Mar 29, 2012 7:43 pm

Impressive photos and technique. How do you go about sectioning and mounting something like this?

rjlittlefield · Post by **rjlittlefield** » Fri Mar 30, 2012 12:40 am

Excellent images! Now that I understand better how these things fit together, I really appreciate the view that your fluid-inflation technique gives us.

--Rik

RogelioMoreno · Post by **RogelioMoreno** » Fri Mar 30, 2012 3:37 am

Very nice images! Your mounting technique is amazing.

Rogelio

Cactusdave · Post by **Cactusdave** » Fri Mar 30, 2012 3:38 am

Very nice pictures. Some of this looks very familiar, but I've not seen that interesting central 'fang' in the old mounted preparations I have of Calliphora blowflies.

NikonUser · Post by **NikonUser** » Fri Mar 30, 2012 4:52 am

Thanks everyone for the feedback, much appreciated.
Actually this is not THE House Fly (Musca domestica) but a member of the house fly family Muscidae.

I called it a "House Fly" to emphasize that it belongs to a different family than those flies used by Rik and Dave those being Blow Flies in the family Calliphoridae.

Oldroyd in his book "The Natural History of Flies" comments that muscid flies mop up blood that is flowing from wounds and some help the blood to flow by scratching at the skin with prestomal teeth developed from the ring of pseudotrachea. The species illustrated here has the tools, those 2 fangs, for such a job.

Mounting was simply done by flattening the labella (tip of the proboscis) under a coverslip; after softening the fly head in 5% KOH, washing in water and inflating the proboscis wiith absolute alcohol

Mitch640 · Post by **Mitch640** » Fri Mar 30, 2012 5:18 am

Your images are always excellent, but it's not the pretty pictures that amazes me. It's what you can do with a dead fly, or any other bug, to get to the subject of the images that is simply astounding to me.

NikonUser · Post by **NikonUser** » Thu Apr 05, 2012 1:24 pm

Thanks Mitch.

The Golden Dung Fly (Scathophaga stercoraria) is a popular subject here on PMG.net. These flies are predators and capture other flies as large as themselves in their legs.

According to Oldroyd (The Natural History of Flies) they use their prestomal teeth (2 sets of 6 in this fly) "to cut a hole in the membrane of the neck, severing the nerve cord, and crippling the victim" - I guess it would.

These teeth are sharp-pointed and the larger teeth are heavily sclerotized.

Image below is one set of teeth; 40x SPlan Apo + 2.5x relay lens; 12 frames @ 1µ; ZSPMax.

NU12037

Planapo · Post by **Planapo** » Mon Apr 23, 2012 10:57 pm

Wow, somehow I had missed these before. Great, and likewise the info.

It here really looks like the prestomal teeth could have well evolved from the bifurcated 'spokes/brackets'. Would be the often entcountered conservative way of evolving a 'new' (i. e. one with different function) structure by gradually altering an already existing one.

--Betty

Mitch640 · Post by **Mitch640** » Tue Apr 24, 2012 4:51 am

Hollywood wants a cast of those for the next monster movie.

lauriek · Post by **lauriek** » Tue Apr 24, 2012 1:25 pm

And Dung flies look so sweet!

NikonUser · Post by **NikonUser** » Wed Apr 25, 2012 3:25 am

Planapo wrote: It here really looks like the prestomal teeth could have well evolved from the bifurcated 'spokes/brackets'. Would be the often entcountered conservative way of evolving a 'new' (i. e. one with different function) structure by gradually altering an already existing one.

--Betty

Right on!
Perhaps if these images had been posted before the original "spokes" more of us would have been skeptical about calling those "spokes" teeth.
Maybe pre-prestomal teeth.