Sawfly Saws - how they work

NikonUser · Post by **NikonUser** » Tue Apr 19, 2011 1:28 pm

Did I ever get this wrong

I put the apparatus back to how it should be, except that part A is the left side part, there is an identical part on the right.

Rather than being on the inside of the 'sheath' consisting of a left half (L) and a right half (R), the edge labelled A and the edge labelled B fit together in a tongue-and-groove setup.

So, rather than having a single edged saw these wasps have a double-edged saw (one edge pointing back (dorsal) and one edge pointing forward (ventral).

My interpretation is that the stiffer valves (R & L) are pushed into the twig. and then part A slides into the tiny hole formed by the tip of L; A and L then work back and forth to cut a slit in the twig.

NU11057

Mitch640 · Post by **Mitch640** » Tue Apr 19, 2011 1:41 pm

In metal work, this arrangement would be called a nibbler. Hand held like a saber saw, air powered, it "nibbles" through thin metals, following any pattern you want.

NikonUser · Post by **NikonUser** » Wed Apr 20, 2011 8:35 am

Another image from a different species of sawfly showing tips of saws as they are found in situ.
20x SPlan Apo +2.5x relay lens, 41 frames @ 4µ ZS PMax

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Mitch640 · Post by **Mitch640** » Wed Apr 20, 2011 8:59 am

I'm curious. How much of this has been known, and for how long? I can't find any images or descriptions like this online, anywhere. Are you breaking new ground here?

NikonUser · Post by **NikonUser** » Wed Apr 20, 2011 9:40 am

I've no idea Mitch. I just make this stuff up as I go along. That's how I got it wrong the 1st time. I'll take a look at some of my text books later.

Mitch640 · Post by **Mitch640** » Wed Apr 20, 2011 10:44 am

Well, it wouldn't surprise me if this was all new knowledge. I have gotten that feeling before in this forum. There are some world class people doing world class imaging right here every day. There simply is no other place like it that I have seen.

NikonUser · Post by **NikonUser** » Wed Apr 20, 2011 10:55 am

I found this from Google; but have to pay to get full article

Egg deposition behavior in the haplodiploid sawfly Athalia rosae ruficornis Jakovlev (Hymenoptera: Symphyta: Tenthredinidae)
JM Lee, Y Hashino, M Hatakeyama, K Oishi… - Journal of insect …, 1998 - Springer
... the two pairs of saws (ovipositor). The "inner" blade (arrowhead) is loosely connected to the
"outer" blade (arrow) at the rim, and the inner blade slides back and forth while the outer blade
is held still (also see text). Scale indicates 0.5 mm. Egg Deposition Behavior in a Sawfly ...
Cited by 13 - Related articles - Get at CISTI - All 8 versions

Mitch640 · Post by **Mitch640** » Wed Apr 20, 2011 11:05 am

I did search earlier today, and yesterday, and did find a number of dry text explanations that for all practicle purposes did nothing to enlighten me. Having never seen a sawfly before, text means nothing, but your images make it all instantly clear.

Theres nothing like a picture to clear up a mystery.

ChrisR · Post by **ChrisR** » Fri Apr 22, 2011 3:51 am

I never saw a saw fly as you saw you see but if I saw a saw fly, what would a fly saw fly bee seen sawing?

Seed?

NikonUser · Post by **NikonUser** » Fri Apr 22, 2011 4:47 am

ChrisR wrote:I never saw a saw fly as you saw you see but if I saw a saw fly, what would a fly saw fly bee seen sawing?
Seed?

Did you mean to write "I never saw a saw fly as you saw a saw fly, but if a sawfly saw a saw fly, what would make a sawing saw fly? perhaps a house fly."

Seed? No, wood.