Midwest Native Plant Society sponsored a one-day workshop on pollinators. It was well attended, with over 140 participants. The speakers were great, fun was had, and there were field trips following the indoor sessions.
The venue was the U.S. Army Corps of Engineers' fabulous visitor center at Caesar Creek Lake in Warren County. We really like holding events at this place, as the conference room is perfect for groups of up to 175 or so people, AND one only need step outside the doors to get into interesting habitat. As proof, one of our field trip leaders, John Howard (striped shirt, back to camera) shows a group a huge female Dobsonfly on the wall by the doors. There was also a stunning Cloudless Sulphur butterfly in the raised flower bed, near that rock.
NOTE: The Saddleback in this photo is a proxy for the actual specimen that we found. I imaged the animal above two years ago in southern Ohio. Scroll on and you'll see why I used a substitute image to show what one of these cats looks like.
Braconid wasps and tachinid flies, among others, are parasitoids. Parasitoid insects such as these generally kill their hosts. One of these flies or wasps lays its eggs on - or injects them into - the victim. The eggs hatch quickly, and the tiny grub begins boring its way through the host's body, consuming non-vital tissues at first. Obviously, as evidenced by the photo above, many such larvae might occupy a host. The parasitoids cleverly avoid consuming the organs that allow the caterpillar to continue to remain mobile and thus better elude other predators, such as birds. Finally, in a grisly last hurrah, the larvae finish off the victim and burst from the dead husk and spin tiny cylindric cocoons.
I had the vial in my office, and when I checked it around 10 am, a few wasps were flying about within. An inspection of the cocoons revealed that most appeared ready to hatch, but in spite of regular monitoring, no more emerged during the day.
It doesn't take long for one to pop out. As the pupa matures into an adult wasp, the outer edges of the summit (lid) of the cocoon get thinner and more fragile. The wasp then apparently chews a very neat incision around the summit of the cocoon, and when the time is right, it pushes up and pops the lid off. From the time that I could detect an obvious movement of the lid in the case of the wasp above, it was probably only 30-45 seconds before it had broken completely free of the cocoon. The three cocoons to the right of the wasp still have their occupants. Other cocoons have the lids popped and we can see the almost perfectly circular shape of the lid.
Making images of these insects was not easy. The wasps are probably only 2-3 millimeters in length - smaller than can be effectively dealt with by using a "normal" macro lens such as my Canon 100 mm. Thus, I resorted to the tricky but useful Canon MP-E 65mm "mega" macro lens, which magnifies up to 5x life size. But this lens is not forgiving, and very hard to use on objects that are moving. It has no focusing system; the operator just moves the camera back and forth to focus. Depth of field is extremely shallow, even at f/16 (what these images were made at), and front of the lens flash is essential. And it is nearly essential that the camera be firmly braced in some way.
But if all goes passingly well, we can see into a micro world that is far too small to be visible to the unaided eye.
The wasp family Braconidae is immense, and undoubtedly includes scores of species as yet undescribed. I have no idea what species these wasps are, or even the genus. Identification of species in this group is the bailiwick of specialized experts, and I suspect specific identification isn't even possible in most cases without a specimen in hand. If anyone reading this can shed more light regarding identification, please let me know.
A fate such as documented above is very common in the caterpillar world. Those of us who regularly hunt for caterpillars are quite used to seeing victims bristling with wasp cocoons, and/or the shells of empty tachinid fly eggs stuck to their exteriors.
Very little in Nature is Disneyesque.