Focus stacking a live and active BMSB

[rjlittlefield]

Brown marmorated stink bugs are not inclined to sit still for very long, at least with strobes going off around them. This presents a big problem for focus stacking.

Here's the solution that I used to shoot the beast at https://www.photomacrography.net/forum/ ... hp?t=40624 .



The main component consists of a small piece of balsa, with three short segments of insect pin embedded in it, epoxied to the middle of the bug's back. For photography, the pins stick onto a small magnet which in turn is epoxied to the end of a piece of balsa, which can then be pinned in any orientation needed for photography.

The image above shows my prototype, attached to a dead and dried specimen.

Here's the setup in action, holding the live bug on its back so that I could photograph the underside of the thorax.



Here are the images seen by the camera with 2X and 20X objectives:





The cuticle of the bug is a little bit flexible, so at 20X it moves around quite noticeably when the bug waves its legs, stretches its neck, and so on. But I've concentrated on an area that's close to the glued fitting, and if I'm lucky, the movement will be mostly correctable by Zerene Stacker's alignment procedure (X,Y,Rotate), leading to a clean final result.

Here are animated GIFs showing the worst two adjacent frames in the 20X stack, before and after alignment.



When the photo session is over, the "backpack" just pulls away from the magnet, and then what's left is light enough that the bug can move around pretty much unencumbered. Kept in my usual plastic boxes, the bug has no trouble climbing vertical walls. But interestingly, the bug is now not willing to attempt hanging from the top of the box, though it regularly did that before I added the fitting. Occasionally it puts a front foot on the top, but that's as far as it goes. All I can guess is that somehow it figures out how much grip it will have, decides that it's not enough, and pulls back. This is actually quite a relief for me, because I was having bad visions of the critter trying and falling, again and again. No problems there, though.



--Rik

[Olympusman]

I'm always amazed by the ability of insect pulvilli to enable insects to crawl up on glass.

Mike

[elf]

Would 3M type 77 adhesive make it easier to remove the fixture after the shoot?

[rjlittlefield]

Would 3M type 77 adhesive make it easier to remove the fixture after the shoot?

I must be missing something. This page at 3M.com describes 3M™ Super 77 Multipurpose Adhesive as being a permanent spray adhesive. What's the product that you're thinking of?

--Rik

[elf]

Not missing anything. I think it's fairly weak, so it might be removable. There are probably better adhesives that can released easier without harmful chemicals.

[rjlittlefield]

OK, so then regarding removable tethers...

Many of the episodes in Thomas Eisner's book, "For Love of Insects", describe tethering insects and spiders. Eisner's tethers were removable, a trick that he achieved as follows (page 126-127):

Thank heaven for dental wax. Dentists use it to make dental casts. I find that I too need to have it within reach. I keep in in the laboratory, and keep a sample of it in my collecting bag, along with [long list of tools].
So why the dental wax? Because it sticks to insects. I don't know its composition, but I know that it is better for the purpose then bee's wax or paraffin wax. I use dental wax to fasten insects to a tether or to attach something to their body. The wax has to be melted to be applied but the melting tempoerature is low enough so the insect is not hurt. The wax also hardens quickly on application. But most important, it comes off easily after the experiment, so one can return the insects to their cage or to mother nature. Carrying dental wax means carrying matches as well, in addition wto wire, thread, and whatever else one might want to use to tie an insect down. It all fits in a little box in the collecting bag.

Perhaps if I had a supply of dental wax on hand, and had built up some skill in using it, I would have gone that route. Surely that would have endeared me to the ethical treatment crowd. But I was more concerned with getting an attachment point that for sure would not move once attached, and since at this point I have only one live BMSB, I wanted to minimize the risk of not getting the photos I wanted. Quick setting epoxy seemed like the best bet in that regard.

By the way, there's one other detail that I did not mention. Before gluing on the attachment point, I took the precaution of putting a few small dots of epoxy in places that would keep the bug from spreading its wings. That also confirmed to me that the bug would not react badly to the chemistry in the epoxy. Those extra dots turned out to be a good choice, between after I stuck on the main attachment and before the epoxy had hardened, the bug climbed to a high point and assumed a head-up-ready-to-launch posture that looked to me like it surely would have burst into flight if it had been able to do that.

I had expected the epoxy to be permanent, but I notice this evening that the extra dots have peeled off in places and the wingtips are slightly separated. I'll have to take another look at that issue before doing another photo session. It definitely would not be good to have the wings popping open in the middle of a shoot.

--Rik

[elf]

When you said dental wax, I thought perhaps machinable wax would work, but the melting temperature is probably too high. Dental wax seems to be readily available at any drug store pretty economically, but I don't know if it's the same type of wax as Thomas Eisner used.

[rjlittlefield]

I am perversely pleased to report that sometime within the last couple of hours, the live BMSB has slipped its bonds of epoxy and is once again walking around unencumbered:



Exactly how it did this, I have no idea. The BMSB has just been hanging around on the sidewalls of its container for the last couple of weeks, and now this. Life finds a way!

--Rik

[dhmiller]

These particular critters are not nice guys. I have no problem terminating them:
Brown marmorated stink bug (BMSB) is an invasive bug that is a serious pest of fruit, vegetable, and other crops. It also becomes a nuisance pest of homes as it is attracted to the outside of houses on warm fall days in search of protected, overwintering sites and can enter houses in large numbers.
-https://extension.psu.edu/brown-marmorated-stink-bug

But your solution is quite elegant. ;-)