question -Relaxing beetle bits (surfactants & chemicals)

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MaxRockbin
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question -Relaxing beetle bits (surfactants & chemicals)

Post by MaxRockbin »

I've been trying some different ways of relaxing the joints on beetles and other bugs.

I just purchased some appendage relaxer from insects4sale.com which is supposed to be basically Ammonium hydroxide + surfactants (aka wetting agent aka surface tension releaser).

Unfortunately, when trying to apply it to the joints of a smallish (1cm) beetle, I found the droplets coming out of my very small syringe are huge compared to the leg joints. It was hard to get the joints covered with the fluid.
(I've tried adding some photo-flo wetting agent with some improvement but not a lot. I can sort of roll the droplets over the joint and they look like they're getting a bit wetter).

Any suggestions?

I've also tried leaving the bugs overnight sitting on vinegar soaked paper towels in a closed container with some success. But some joints don't yield and sometimes other bug bits yield too much and drop off.

Thanks!
If your pictures aren't good enough, you're not close enough. - Robert Capa

Charles Krebs
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Post by Charles Krebs »

I'm certainly nowhere near as experienced as others, but the basic "relaxing chamber" has worked well for me. You do need patience. Overnight may not be long enough. I will sometimes re-wet the underlying absorbent material with warm water a time or two during the process.

Have a look at these links:

http://insectnet.proboards.com/thread/1 ... ng-beetles

http://extreme-macro.co.uk/relaxing-insects/ (by forum member Johan)

MaxRockbin
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Post by MaxRockbin »

Thanks! It does seem like just using a relaxing chamber (and more patience) is probably going to work best. I was hoping to find something faster, but sometimes you just have to wait.

The ammonium hydroxide applied with a syringe did work for a longhorn beetle, but even after a double dose and some flexing, the limbs still tended to return to a clench (though not as much as before).
And the antennae actually got too relaxed and shifted a bit while shooting a stack.
If your pictures aren't good enough, you're not close enough. - Robert Capa

Ichthyophthirius
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Post by Ichthyophthirius »

Hi,

It depends on how the insect was killed. If it wasn't killed with ethylacetate, for example if it died naturally, the legs can remain very stiff.

It's got something to do with the denaturation of collagen during and after death.

Insects killed with ethylacetate: put in a moist chamber (water vapour only, no direct contact with the water!) with water and thymol (to prevent mould) overnight. Tough larger insects might need longer. Very tough beetles can be floated in diluted acetic acid.

Insects that died naturally: same as above; might take longer; in that case take extra care the insects don't get mouldy. Then arrange the beetle with pins https://beetlesinthebush.files.wordpres ... 00_usm.jpg and air-dry for a few days before taking photos.

Very tough beetles can sometimes be relaxed http://markgtelfer.co.uk/beetles/techni ... labelling/ by digesting the denaturated collagen with pepsin (enzymes) http://markgtelfer.co.uk/beetles/techni ... /relaxing/

Regards, Ichthy

MaxRockbin
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Post by MaxRockbin »

Thanks! Very useful info.

Per one of the websites on the subject, I've got a couple of boxelders in a relaxing box with paper towels wet with distilled vinegar (aka dilute acetic acid). I'll give them a couple of days. They are actually in contact with the paper towels. I hope that's not too damaging.

I hadn't tried just water (with no contact). That would be easier and less smelly...
If your pictures aren't good enough, you're not close enough. - Robert Capa

johan
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Post by johan »

Water on its own works, but be careful you don't get mould growing. Every method I've tried has its up and downsides - 24-48hr in vinegar on a paper towel in an airtight container on a pc (for a bit of heat) seems to be best compromise. The Watkins & Doncaster stuff is really stinky.
My extreme-macro.co.uk site, a learning site. Your comments and input there would be gratefully appreciated.

MaxRockbin
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Post by MaxRockbin »

Thanks for the tips Johan. I just pulled a couple boxelder bugs from my vinegar in tupperware relaxing chamber and it seems to work very well If given enough time (previously I had only tried 24 hours and that wasn't cutting it). I haven't tried just plain water yet.

Also after reading your page on insect positioning on extreme-macro.co.uk, I made myself some hooks and holders by bending insect pins and super-gluing them to sticks. It is so much easier than poking and prodding them around with pins and tweezers. Thanks!

A related tip I just learned from "insects4sale,": foam insulation boards from a home supply store can be better than regular styrofoam for a pinning surface because it's smoother, so the little feet don't snag as much. (I've also tried putting scotch tape on top of styrofoam and that seems to work as well).
If your pictures aren't good enough, you're not close enough. - Robert Capa

MaxRockbin
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Post by MaxRockbin »

An update and Relaxing Question Part II: Drying?

My target for relaxing is this 8mm Western Boxelder Bug Nymph, which has a very attractive pattern. This is a live specimen photographed through a stereo microscope eyepiece with an iPhone (focus is tricky doing this and it usually takes me several shots to get a decent one):

Image

After relaxing 48 hours in tupperware with vinegar soaked paper towels (in contact with the bug), I cleaned him in a TSP/surfactant solution, then rinsed quickly in 99% isopropyl, then put in a fair amount of time in my first ever effort at pinning a bug in position (the bug limbs were very flexible, but the body not squishy. Seemingly perfect):

Image

Then I left him outside to dry in the sun for a day (pretty warm weather we're having). I thought that's what you're supposed to do. Dry them out and the legs hold in the pinned position. This is where it all went horribly wrong. The bug potato chipped. His body deflated. (Sorry - not a great pic):
Image

SO: The question is, after relaxing and pinning, how do you dry them without the punctured football look?
Or did I just relax him too much in the first place?

Thanks!
If your pictures aren't good enough, you're not close enough. - Robert Capa

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Post by rjlittlefield »

Somebody else may know magic, but as far as I know, for all practical purposes you were doomed as soon as you decided on that particular subject.

The reason is that the abdominal shell of that beast is very soft. Its shape is normally maintained by being filled with water-saturated tissues. When the water evaporates, the tissues shrink and the shell collapses along with them. The result that you show is typical.

Insects that keep their shape when dry are the ones with hard shells. Beetles are by far the best. Adult true bugs, like an adult Boxelder Bug, may work OK too, especially in dorsal view where any shrinkage of the abdomen will not be so obvious. Insects that have black eyes when alive are best, since any eye that is not black will change appearance as it dries.

With soft-bodied insects like your subject, as far as I know it's an unsolved problem how to make the tissues firm enough to hold a pose, without significantly changing their appearance. I imagine that vacuum freeze-drying or triple-point drying would be your best bets, but those processes are not easy to do without special equipment. With a lot of waiting, freeze-drying can be done in an ordinary home freezer at normal atmospheric pressure by putting the specimen in a sealed container with a strong desiccant like silica gel.

--Rik

MaxRockbin
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Post by MaxRockbin »

At least it was educational (and maybe an incentive to get out there and try shooting some live subjects).

Freeze drying seems like an interesting idea. I already have a bunch of bugs in the freezer. A couple silica gel packets can't hurt.
If your pictures aren't good enough, you're not close enough. - Robert Capa

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Post by rjlittlefield »

In that case, see http://images.peabody.yale.edu/lepsoc/jls/1960s/1969/1969-23(1)43-Flaschka.pdf (Flaschka, H., and J. Floyd. 1969. A simplified method of freeze drying caterpillars. J. Lepid. Soc. 23:43-48 ).

--Rik

MaxRockbin
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Post by MaxRockbin »

That's a useful paper. Except -- "3 to 6 months" (!)
Their table showed about 100 days to remove 3/4 of the water for the specimen they were testing. Of course, caterpillars are larger than many other bugs and would take longer.

Still, I need to start prepping bugs for winter now!

An interesting part of the paper described how to freeze caterpillars into a natural position: First put them in the fridge till they're pretty much dormant (but not curled and dead), then put them in the freezer for the coup de grace and they won't curl. I think I did that accidentally once and it worked.
If your pictures aren't good enough, you're not close enough. - Robert Capa

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Post by rjlittlefield »

There are a couple of other papers hosted by the same place, also from Journal of the Lepidopterists' Society. You can find them by Google search for freeze drying "journal of the lepidopterists society".

They describe how to make the process faster by drawing down the pressure by various amounts.

The ideal situation is to get complete evacuation, which provides water molecules with an uninterrupted free path from the surface of the critter to the desiccant.

But substantial improvement can be made at significantly lower pressures.

The paper titled "Low Cost Vacuum Freeze-Drying" describes using a water aspirator to cut the drying time for an "average butterfly larva" from 100 days at 760 mm Hg to 14 days at 15 mm Hg (versus 2 days at 0.001 mm Hg, described in "Practical Freeze-Drying and Vacuum Dehydration of Caterpillars").

--Rik

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Post by Chris S. »

rjlittlefield wrote:Somebody else may know magic. . . .
I don't know magic, but I wonder--to your knowledge, Rik, has anyone tried injecting the abdomen, after drying, with something that would puff it out to life-like shape?

--Chris

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Post by rjlittlefield »

Chris S. wrote:as anyone tried injecting the abdomen, after drying, with something that would puff it out to life-like shape?
Puffing it out after drying won't work, I expect, because the shell becomes brittle when dry.

You can imagine keeping it puffed out while drying, but I don't know of anything that would give good results for photography purposes.

One classic method of preserving the external appearance of caterpillars in a dry collection is to make a small hole at the tail, squeeze out the abdominal contents, then insert a thin pipette and inflate the specimen with gentle air pressure, all the while heating it gently. I guess a skilled worker can get pretty good results; I never did.

As for injecting some fluid, the difficulty there is to get the "inflatant" to stay inside the abdomen, without leaking out and wetting the exterior. There are fun and games you can play with various fluids, but I don't know of any combination and sequence that will end up with a specimen that is simultaneously inflated and dry.

The closest I've ever come to that is the blowfly that I started in water and gradually switched to acetone, then let it dry completely. That was very successful at keeping the proboscis inflated (actually over-inflated by quite a bit), and incidentally it left the rest of the body looking almost fresh, except for the eyes. I once gave a cutworm caterpillar a similar treatment and got good results with that.

So, the water-->acetone technique is still on my list of things to try again, but only in those special cases when I really need a dry specimen and it's not naturally hard-shelled, and I don't mind still getting some clear changes from live or fresh appearance.

--Rik

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