Natural History question

[Nancy Bell]

I collected this lady bug from a mullein plant yesterday. Today I set it up in my white box set up and watched this caterpillar-thing appear from somewhere near the rear (inside) of the lady bug and proceed to create a cocoon binding the legs of the lady bug and the underside of the lady bug. This took about an hour. Does anyone know what might parasitize a lady bug and build a cocoon? It seems the lady bug still twitches, but maybe it is the caterpillar inside the cocoon.

Also I had an impossible time trying to photograph this. I just could not get it sharp. My set-up is inside, in the white box. Canon 5D Mark III, Canon 100 f2.8 macro lens, tripod, macro twin lights set at flash +2, 1/200, f16, ISO 1600, manual exposure. I used live view to focus. I wanted good depth of field and I needed some speed since this caterpillar was building the cocoon quickly. The macro twin lights are each covered with a plastic translucent diffuser. Suggestions most welcome as I would like to know how to photograph a small insect with this set-up.

[Mitch Haimov]

I'm no help with the parasite ID, Nancy. But it is certainly an interesting natural history moment.

You're fighting physics with your DOF issue, and that's a fight you can't win with brute force--there is only so much DOF available no matter how much you stop down the aperture. And the more you increase magnification the narrower the DOF becomes. But where brute force fails, you can sometimes win through guile. That is, you can make you image appear to have more DOF by carefully positioning your camera to get as many important parts of your subject within the DOF as possible by putting them all as close to the same distance from the sensor (or film plane) as you can, aka photographing from a magic angle. In this case, you are shooting down on your subject at an angle but you want to be parallel to it. Since your subject wasn't going anywhere, you could have put something under the leaf to prop the back up so that the plane of focus went through the the parts of the composition most important to you, perhaps near eye, the two legs extending down, some of the near edge of the elytra, and the left end of the cocoon. This is what I tried to do with my recent lady beetle thread (http://www.birdphotographers.net/forums/showthread.php/113693-No-Aphids-On-My-Apple). In my image the majority of the frame is OOF but enough of the important bits are sharp that the image appears to greater DOF than it actually does (my image actually has less DOF than yours due to its higher magnification, but it appears to have more). Would have taken some futzing with your tripod and/or the position of your subject to find the magic angle, but you could have accomplished the same effect with this subject. With a more active subject you would probably need to forego the tripod. I know, ditching the tripod to get more sharpness in your images sounds insane, but with a short flash duration and a forearm resting in the same table as the light box it turns out to be quite doable. Tripod adjustments simply take to long to react to an active subject at high magnification. You have nothing to loose and a world of new possibilities to win by trying. Have fun!

[Nancy Bell]

Mitch, thanks so much for the super helpful info on small critters and DOF! I was thinking of your lady bug image while I was attempting to capture mine.

[BillTyler]

Hi Nancy,

It's a really interesting moment! know that a number of wasps are parasitic in just this way, and I'd suggest watching to see what eventually hatches.

I have a few technical suggestions for the issues you raise. Focus stacking can be a real help in getting deep DOF with a stationary subject. If you're not familiar with the technique, Wikipedia has an article that goes into some detail. The basic idea is to take a stack of images, all focused slightly differently, and then combining them with stacking software such as Helicon Focus. For a subject this small, I'd suggest changing focus by either moving the camera or the subject, using a geared focusing rail. If you try to focus by changing the lens setting, you'll wind up with images that are all made at slightly different magnifications. Because you're going to stack a lot of images, you can afford narrow DOF in each individual image, and therefore can use a somewhat wider aperture, which helps a lot with diffraction.

One other item I've found useful for an indoor studio setting is a studio-type monolight. These things put out a ton of light compared to the macro twin-flash, and you can simply aim the monolight at a large diffuser held over the subject to get bright, even light. Doing this, I have to dial my monolight down almost to its minimum to get a correct exposure at f/11, ISO 200, and that's AFTER going through the large diffuser. In addition to tons of light, you also don't have to worry about the heads of the macro twin-light banging into things as you shoot.

[Nancy Bell]

Thanks Bill for more info. At the moment I've added a desk lamp to my set-up. At least it is helping me see enough to focus better. I see the basic concept of focus stacking. I must try it!
Here is what I found on my parasite from Living Science: If a ladybug's life were a horror film, this is how it would start: Scary string music. A close-up of the green-eyed face of a wasp. The sudden pierce of a stinger. The screen goes dark.
Next, an establishing shot of our ladybug hero, sitting placidly on a leaf. Suddenly, the sky clouds over. Something orange and grubby (http://www.livescience.com/11369-10-favorite-monsters.html) begins to poke from the ladybug's abdomen. Audience members cover their eyes, expecting a quick, gruesome end for the black-and-red insect. But it's not that easy. Instead of dying, the ladybug survives as a wasp larva emerges from its abdomen and begins to weave a cocoon between the ladybug's legs. That's right: The ladybug is a zombie.
This sordid tale isn't fiction for many ladybugs that fall victim to the parasitical wasp Dinocampus coccinellae. Now, a new study reveals why the wasps use ladybugs as incubators. It turns out that the zombie ladybugs keep predators away from the wasps' vulnerable larva, increasing the likelihood that they survive to become full-fledged wasp. About 25% of the lady bugs survive this ordeal and resume their normal life.

[Mitch Haimov]

Wow! Thanks for the Living Science excerpt. Quite interesting. And rather astonishing that 25% of the lady zombies "resume their normal life!"

I'm glad you found my post helpful. I didn't think of focus stacking at the time, but its a good option when your subject is static. The twitching and the cocoon construction may have made it a challenging technique to apply here. If you decide to try it and you want stacking software that is more robust than what Photoshop will do in this arena, I recommend reading reviews before deciding which software to purchase. The leaders are Helicon Focus and Zerene Stacker. I have seen excellent results from both, but one may be better suited to the way you work than the other.

[BillTyler]

For some superb examples of parasitic wasp photos, you might want to take a look at some of Alex Wild's work. Here are some links to parasitic wasp related photos.
A wasp ovipositing into a hornworm. http://alexwild.smugmug.com/Insects/Insect-Orders/Bees-Wasps-and-Sawflies/i-xjDxXkS/A
A hornworm with wasp pupae sticking out its back at http://alexwild.smugmug.com/Insects/Insect-Orders/Bees-Wasps-and-Sawflies/i-KTKdtrW/
A closer look at the hornworm with pupae: http://alexwild.smugmug.com/Insects/Insect-Orders/Bees-Wasps-and-Sawflies/i-4TbqjKQ/A
An inchworm with wasp pupae sticking out of its back at http://alexwild.smugmug.com/Insects/Insect-Orders/Bees-Wasps-and-Sawflies/i-rqRDf6X/A

Bill

[Jonathan Ashton]

A really interesting image Nancy, on that tells a story. I think you did a fine job and I have enjoyed reading the comments it has generated. Regarding the image I think you have to take what you get and there is little you could do really in terms of enhancing presentation - but as I said I think you did a fine job here.