The face behind the mask (cricket mandibles)

[rjlittlefield]

============== I had no idea! ===============



I mean, crickets normally look like such cute friendly little guys.

Soft little palps, soft little faces, soft little...well...soft. Cuddly, almost. Jiminy Cricket, and all that.

But it turns out there's a dark side to those soft little critters, and the photo above shows the face behind the mask.

The story here is that several weeks ago I caught a big female praying mantis.

I figured the mantis needed something to eat, and there was not much left in the wild, so I went to the local pet store and bought some crickets. Acheta domestica, said the salesman, your basic "European house cricket". I got a dozen of them.

But the mantis laid her eggs and died of old age before she ate all the crickets.

"Turn about is fair play", it seems, because the crickets then ate what was left of the mantis.

"How do they do that?" I wondered in passing. Mantis hide isn't exactly delicate stuff. But I didn't follow up on the question.

Not until the crickets started dying of old age too. And not even then, until one of them happened to die in a most unusual posture.

It turns out that the face of a cricket is mostly covered with a fleshy flap divided into parts named the "clypeus" and "labrum". (See diagram, here.)

In its last dying movements, this particular cricket had apparently spread its mandibles, thrust its clypeus and labrum between them, then chomped down, leaving the mandibles exposed for me to notice.

I have since checked other corpses. They all have mandibles just like the ones shown here, but they are incredibly well hidden. Jiminy Cricket, indeed!

Following is a side-by-side comparison -- normal Jiminy Cricket posture on the left, the pictured specimen on the right.



Hope you find this as interesting as I did.

--Rik

Technical: First image using Canon 300D with 38 mm Olympus bellows macro lens at f/4, stacked at 0.002" focus step. Halogen fiber illuminator, pingpong ball diffuser.

[Ken Ramos]

A wolf in sheeps clothing? I really like these images , though I never suspected crickets to have such tremendous chompers. Wonder if Disney knows about this? Probably so but kept it a corporate secret I suppose.

[Michigan Michael]

Good stuff, Rik.
Interesting and educational.

[JoanYoung]

Thanks for an extremely interest post Rik, and great pics too. Wow, these are some ugly mandibles!!

[cactuspic]

My, what big mandibles you have, grandmother....Very interesting story about how curiosity lead to good photography, Rik. On a technical note, I think the glare on the mandible may partially be eliminated by a polarizier.

Irwin

[MacroLuv]

It looks sharp as a shark's tooth.

[rjlittlefield]

My, what big mandibles you have, grandmother....Very interesting story about how curiosity lead to good photography, Rik. On a technical note, I think the glare on the mandible may partially be eliminated by a polarizier.

Irwin

Thanks, Irwin.

As it happens, I worked very hard to get that glare just as it appears here -- three different diffusers and a zillion different light placements got tried and rejected, before I settled on what you see here.

Look closely, and you'll notice that none of the glare is blown out, while every ridge, valley, pit, bump, and scratch can be clearly seen. Without the glare, most of that info disappears -- all that shows is a dark shape. If I wanted to highlight the color of the material, a polarizer would be a blessing. To highlight the shape, it's a curse. Different tools for different goals...

--Rik

[Charles Krebs]

Rik,

Very impressive image! And informative as well... never would have guessed it if you had posted the shot as a "quiz"!

[cactuspic]

My, what big mandibles you have, grandmother....Very interesting story about how curiosity lead to good photography, Rik. On a technical note, I think the glare on the mandible may partially be eliminated by a polarizier.

Irwin

Thanks, Irwin.

As it happens, I worked very hard to get that glare just as it appears here -- three different diffusers and a zillion different light placements got tried and rejected, before I settled on what you see here.

Look closely, and you'll notice that none of the glare is blown out, while every ridge, valley, pit, bump, and scratch can be clearly seen. Without the glare, most of that info disappears -- all that shows is a dark shape. If I wanted to highlight the color of the material, a polarizer would be a blessing. To highlight the shape, it's a curse. Different tools for different goals...
--Rik

Rik,

I would be the last to recommend the use of a polarizer to eliminate the highlights in the subjects eyes or criticize a conscious artistic choice to use glare. I do want to get more info about your statement that without the polarizer everything would have gone dark and detail would have been lost. I have had numerous times where the polarizer has not helped the detail or shape at all. I have never knowingly observed a situartion where detail such as scratches or bump or tonal gradations were lost due to a polarizer. I don't claim to know the science (I can't even tell you how a polarizer works), but it does run contrary to my basic understanding and experience. It's my understanding that removing the glare will allow you to see texture and shape better, such as using a polarizer to allow you to see into water better.

Having looked at the photo several times again while writing this, are you approaching this as a problems of sensor latitude, where the difference between the light and dark tones are too great for the sensor to hold detail in both? And because the glare had the effect of lightening dark sections of the image, the details that would have otherwise been blocked up are now lightened and registering?

Please forgive my ignorance in this matter. I am just trying to more fully understand the use of a simple (hah) polarizer.

Three different diffusers on a cricket jaw...lol. You must be using pinpoint lighting. How did you light the mandible?

Irwin

[rjlittlefield]

Irwin, the best answers to your questions are visual, but that will have to wait until tomorrow. In the meantime, a few words...

It's my understanding that removing the glare will allow you to see texture and shape better, such as using a polarizer to allow you to see into water better.

Ahh, but suppose what you really want to see is the shape of the water.

Try this little experiment. Make yourself a cup of black coffee or dark tea. While it's brewing, haul out some polarizing sunglasses. Now, pour the coffee into a cup. Position it so you have a nice reflection of some background light area, fairly glancing, say around 30 degrees to the surface. Tap on the side of the cup. Watch the ripples. They're easy to see. Now put on the sunglasses. The reflections will disappear. That's what polarizing sunglasses are supposed to do, and they do it quite well. But when the reflections disappear, the ripples disappear too!

If you want to see through the water, then a polarizing filter is just the ticket because it kills the glare. But if you want to see the shape of the water (the ripples), then killing the glare is just the wrong thing to do, and the polarizing filter works against you.

The cricket mandibles are like the coffee. I want to show the ripples.

Three different diffusers on a cricket jaw...lol. You must be using pinpoint lighting. How did you light the mandible?

Um...what I think you read is not what I intended to write.

I tried and rejected three different diffuser arrangements before settling on the arrangement that I finally used. That final arrangement was a single diffuser -- half a pingpong ball with a small circular hole in the middle, illuminated by the two heads of a split fiber. I'll show you a picture tomorrow.

--Rik

[jmlphoto]

wow very interesting, doesnt even look like those things would fit in the head. so now you have some mantis eggs too?

[rjlittlefield]

The answers to Irwin's questions got kind of technical , so I replied over in the Technical forum.

See this post, "Effect of polarizing filters on the cricket mandibles photo".

--Rik

[rjlittlefield]

so now you have some mantis eggs too?

I do!

I don't have a clue what I'm going to do with them, though.

When they hatch, the little ones will be moving around way too much for my favorite stacking techniques to work.

Very impressive image! And informative as well... never would have guessed it if you had posted the shot as a "quiz"!

Thanks, Charlie! You know, posting it as a quiz never occurred to me. Maybe I should think about that more often.

--Rik

[rjlittlefield]

It looks sharp as a shark's tooth.

It sure does!

I did some follow-up study, and I was interested to find that some of that rough and rugged appearance is apparently due to wear.

Here is a side-by-side comparison.



On the left, one of the mandibles shown above, from a specimen that died of old age after eating its way through a mantis corpse.

On the right, the matching mandible from a different specimen, this one fresh from the pet store where I suppose it had only nice soft food to eat.

There is some overall difference in the surface texture, but what really catches my attention is the striking difference in what I assume are wear patterns -- the scratches and faceting along the direction of movement.

--Rik

[Tony T]

Hi Rik:
In a former life I used to work on Blackflies (Diptera: Simuliidae). The larvae live in flowing water, often in very large numbers, and several species overwinter as larvae. Should be easy to find now in any flowing water. Anyway, one of the main characters for ID'ing the larvae are the teeth, they have a whole row of 'sharks teeth' along the front edge of the head capsule, With your skills I bet you could get some interesting, and useful, images.