Thursday, August 28, 2014
We move in...
A cannibal fly on the hunt parks itself a leaf or branch with a good view of the surrounding landscape. When an appropriate victim - usually a large insect - flies into view, the cannibal fly launches itself and proceeds apace towards the prey. There is nothing particularly deft or agile about the operation. Accompanied by a loud buzzing drone, the fly hurtles clumsily but rapidly at the victim, and rams it in midair. Once the prey is met, the cannibal fly enfolds it with powerful spine-covered legs; an entomological iron maiden from which there is no escape.
The coup de grace is then administered. The fly's proboscis is a sturdy tube much like a hypodermic syringe, and it is rammed deeply into the doomed victim. Acidlike substances are piped in, which aid in dissolving the innards, and the liquefied goop is then sucked back out leaving little more than a dried husk. After a well deserved rest, the cannibal fly prepares for the next hunt.
This insect might be thought of as the Peregrine Falcon of the insect world. They are high-end predators, and from my experience are not very common. I see but a few each year, and when I do, the cannibal fly is invariably in some high quality habitat such as a prairie remnant or other open habitat of rich botanical diversity. Lots of native plant diversity breeds lots of pollinating insects, which in turn spawn a fabulous assemblage of predators, and of this latter group, the Red-footed Cannibal Fly is hard to top.
Tuesday, August 26, 2014
Huffman Prairie, and it, like the Wright Brothers' airfield, is part of the massive Wright-Patterson Air Force Base. The base houses some of the most sophisticated aircraft in the world. Incredible how far aviation has come in just over a century.
But I was not here to study the history of aircraft. I had not been to the 100-acre Huffman Prairie in a long time, and had been hearing all about how great it looked this year. So, a few Sundays back I headed to Dayton and met up with Grace Cochran of Five Rivers MetroParks, which serves the Dayton area. She was willing to give me a tour of the prairie, which her park district has a big hand in managing along with the air force base and the Ohio Chapter of the Nature Conservancy. Later, we were joined by Dave Nolin, the park district's Conservation Director and a longtime friend. It was a great trip, and we ended up spending many hours exploring the prairie.
In this shot, Purple Coneflower, Echinacea purpurea, and Big Bluestem, Andropogon gerardii, dominate but plenty of other botanical diversity is visible in the scene.
Had I only been there three weeks prior! That's when Dave made the stunning image above. Remember that for next year - if you wish to visit Huffman Prairie, angle for the tail end of July or the first week in August.
But perhaps best of all, avian-wise, were the Sedge Wrens. As we penetrated deeper into the prairie, we began to hear the males' staccato chatter, which suggests a poorly running sewing machine. These are secretive rather mousey birds prone to foraging, and even singing, in dense cover. Eventually we spotted one as it flew from perch to perch.
In Ohio, Sedge Wrens often don't appear on territory until mid-July or even early August. It is thought that these are birds that already bred at more northerly latitudes, or in the prairie states and provinces to the west. Following that, the wrens move south and east, and nest again in entirely new locales, both in terms of habitat and geography.
Thanks again to Grace and Dave for the tour, and an excellent day in one of Ohio's best prairies.
Sunday, August 24, 2014
As an aside, this was a sensational field trip for me. I seldom get out on dedicated botanical missions anymore, and only rarely with botanists the caliber of this bunch. I'm always looking at plants everywhere I go, of course, but it is entirely special to be afield with people who know EVERYTHING botanical. Our inner geeks can come out, seldom are common names mentioned, no one looks at you oddly for rattling off scientific names, and I don't think one could find a vascular plant that someone in the group would not know. It was fun engaging in friendly debates over the latest in botanical taxonomy, and catching up in the current state of affairs in the plant world. Dan Boone is always fun to engage with. He loves the obscure genera, and is currently on a dogbane (Apocynum) splitting tear. Go Dan.
Rough Boneset has a rather spotty and scattered distribution, and occurs south and east of Ohio. It ranges fairly near in Kentucky and West Virginia, and its occurrence here fits with numerous other species of southern plants that reach their northern limits (at least in the interior) in southern Ohio.
Congratulations to Brian Riley on another in an ever-growing string of fantastic botanical finds. I appreciate him organizing this outing, and inviting me along. I look forward to his next great find.
Thursday, August 21, 2014
However, time was tight, and I had decided to just seek macro material on this brief foray. I struck Odonate gold when I spotted a tiny Fragile Forktail, Ischnura posita, resting on a leaf just off the path. This damselfly is truly Lilliputian; perhaps only the Eastern Red Damselfly, Amphiagrion saucium, can lay claim to such minuteness among our damsel fauna. One might pass off a Fragile Forktail as a strange small fly or some other inconsequential bug without a good look.
The forktail gave me one chance for a shot, and it appears above. The flashes spooked it further into the foliage, and that was that. But this image is not bad, and may help allay some criticism of the difficulty of using the MP-E 65 lens in the field, and without a tripod. As small as this damselfly is, it can barely be squeezed into the MP's field of view, even at its lowest magnification. This shot is slightly cropped; on the original, much of the abdomen was visible, but not the terminal end - it was out of the field of view. Had I had more time to compose, I could have got it all in the image (barely), but I wanted the head shot and was focused on that. You can even make out tiny orangish mites - one between the eyes, one on the lateral black stripe, and a few on the underside of the thorax. With some slight tweaks in Photo Shop, which I have yet to do, the exposure will be picture-perfect.
The MP-E 65 lens has no focus ring - the photographer just moves the camera until the subject comes into focus. Turning the ring on the lens increases magnification, all the way to an amazing 5x power. It is like looking through a microscope. I find I can handhold the rig without undue difficulty at 1x or even 2x; anything beyond that requires some sort of stabilization. An issue with shooting unrestrained live animals such as this damselfly is the very close working distance required with this lens. The front of the lens was probably six inches or less from the damsel when I made the image, and a lot of critters won't put up with that sort of intrusion. If they will, the photographer can bag some incredible images, far beyond what even an extremely capable macro lens such as Canon's 100 mm L-series can produce.
I've only had a few weeks practice with this lens, but am honing in on its sweet spots. The best setting I've found thus far is: ISO - 100; aperture of f/16; 1/200 shutter speed. Flash is essential and the rig to have is Canon's twin lite flash setup, where the flashes are mounted on a ring at the end of the lens. The flash commander mounted on the hotshoe is set to ETTL mode, and communication between flash and camera is generally excellent. The twinlite flashes also have small pre-lights mounted on them, which can be activated with a quick double-tap of the camera's shutter release button. Those lights allow the photographer to easily see the subject and compose the image before firing the shot. Pre-lighting is often helpful, even essential, as the tiny aperture of the MP-E 65 lens lets very little light in and thus one's view through the view finder is often very dim.
If you are a serious macro photographer, I would highly recommend this lens. Of course (and I have no relationship with Canon!), you must shoot a Canon body. No other manufacturer, insofar as I know, makes a comparable lens.
Tuesday, August 19, 2014
I'm on a bit of a wasp jag, but so be it. Wasps are awesome. Yesterday, while taking a quick stroll around the planted prairie at work (described RIGHT HERE), I stumbled into two interesting species. The good ole Canon came through in decent form, and I managed a few images.
It is a Potter Wasp, Eumenes fraternus, and when not visiting flowers for nectar or pollen, these wasps engage in far more grisly behavior.
When on the hunt, these big wasps are frenetic. They clamber about plants in a fast, rather maniacal manner, rapidly inspecting flowers, stems, and leaves for victims. Black-and-yellow Mud Daubers are possessed of extraordinary senses, and if they detect a large bipedal interloper moving in, they're off in a flash.
However, in this case I spotted her from afar, and hung back. I knew she was on the hunt, and hoped she'd score a victim. All of a sudden, WHAM! She spotted a luckless spider cowering on a stem, and whacked it quick as could be. I was ready, and rushed into range, clicking away. The above photo shows her still in the act of stinging the spider with a potent neurotoxin which disables the victim nearly instantaneously. Her abdomen is doubled back nearly 180 degrees, and the ovipositor at the business end is firmly embedded in the spider.
The story is largely the same as the Potter Wasp, except that this species provisions its chambers with paralyzed spiders rather than caterpillars.
If wee beasts were capable of the same level of thought, reasoning, and consciousness that we are, one can only imagine the constant level of terror that creatures such as spiders and caterpillars would endure. Just imagine a giant long-legged wasp tearing your way, and knowing in advance what your fate will be. It would be like living a Japanese horror sci-fi movie, except it's all real.
Sunday, August 17, 2014
The more that I study Nature, the more that I am convinced that one must really look hard at the LITTLE things. At least if one wishes to really develop a deep understanding of ecology, and how organisms are linked together. I am fortunate indeed that I have many friends who feel the same, and will give a caterpillar about the same attention that they would a goshawk.
In this photo, taken on a recent foray, David Hughes (front), John Howard (middle), and your narrator spend some time on the ground - not a rare occurrence for any of us. We were watching the bed of Partridge-pea, Chamaecrista fasciculata, plants that cover the bank in front of us. Numerous ants were visiting the extrafloral nectaries on the plants' leaf petioles, and we were watching them and attempting to obtain images. I wrote about ants and nectaries HERE, should you be interested.
If you look at the rear of the wasp, you'll see she's sticking her very long ovipositor into the flower cluster. I had not seen anything like this before, and could only speculate that she was going after tiny flower thrips, or perhaps some other concealed organisms. As an aside, I would say that Lytopylus wasps must also serve some function as pollinators, judging by all of the pollen stuck to her.
In this photo, we can see her ovipositor quite well. It juts from the rear of the abdomen, makes a few kinks, and then augers down deep into the clump of disk flowers. Female wasps (and bees) are equipped with "stingers", which come in lots of variations. Some can use them to sting, but the primary function is to lay eggs. The Lytopylus wasps are parasitoids - they lay their eggs on an animal host, and the wasp grub consumes the victim.
Apparently Lytopylus wasps are adept at ferreting out the locations of tiny moth caterpillars concealed within the disk flowers of Rudbeckias and similar species in the sunflower family (Asteraceae). The wasp bores down to them with her long wiry ovipositor, and deposits eggs. The caterpillar will fuel the wasp larva's growth, dying in the process. I suspect that these tiny wasps play a vital role in reducing flower predators. In the relatively short time that we watched her, she visited many coneflower blooms, presumably nailing caterpillars in all of them.
Amazing. At least to me.
The life and death drama that constantly plays out on flowers would be the stuff of science fiction, were it not true.
Thursday, August 14, 2014
I got an email a week or so back from a work colleague, Katie Thierolf, letting me know that she had seen numerous of these caterpillars at the state fairgrounds. Being unable to make a trip down there, I implored her to wrangle some of the cats into a jar, and bring the captured livestock back to the office so I could make some images. She did so - thank you Katie! - and some of the images and a story follow.
Rachel Shoop, a biology student at Marietta College, is studying the DNA variation in these species. Perhaps, as part of her work, she will also unearth morphological characters that will enable us to visually separate the two. Such knowledge will make life more satisfying for moth-ers at the mothing sheets.
Oh, the caterpillars used in this shoot were released into a Sycamore tree at our office complex. Hopefully they will establish a local colony of Sycamore Tussock Moths.