Thursday, August 28, 2014

Red-footed Cannibal Fly!

The Slender Ladies'-tresses, Spiranthes lacera, is one of our smallest orchid species, but always a star. Yesterday, I led a group on a trip to explore some interesting natural areas in southeastern Ohio. One of our stops was a very interesting oak barrens that is regularly subjected to controlled burns. Plant life in this locale is spectacular, and includes one of the rarest plants in Ohio. I hope to write more about that species soon. On the hike back to see the rarity, we stopped to admire this diminutive ladies'-tress, which was a "life" plant for most of the group.

But a fly, of all things, ended up stealing the show. Lisa Brohl spotted a large, strange-looking insect and drew my attention to it. Yes! Even from afar, it was instantly identifiable as the gargantuan, death-dealing Red-footed Cannibal Fly, Promachus hinei. Those of us who were bringing up the rear of the group (I'm always last!) were treated to the spectacle of one of our most ferocious insects.

We move in...

The cannibal fly was semi-cooperative, and after a bit of sneaking about, we were able to draw quite near. It was preoccupied. The animal had snared a large bumblebee, and has it in its clutches. Now that's tough! Very little is safe around a Red-footed Cannibal Fly. They, obviously, are not even deterred by insects that can give a nasty sting. This isn't the first time I've seen one with a bumblebee, either.

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

Sedge Wrens at historic Huffman Prairie

This innocuous looking field is the most famous place in aviation history. It was here that two famous brothers from Dayton, Orville and Wilbur Wright, learned to fly. Sure, their first powered flights took place at Kitty Hawk, North Carolina in 1903, but the following year the brothers returned to Dayton, Ohio, and fine-tuned their flying machines on this very field.

Adjacent to the flying field is famous 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.

Rich dark soil - REAL prairie soil! - is the bedrock of the prairie, and much of the general area. Indeed, the Wright Brothers' airfield was a wet fen back in Orville and Wilbur's day, and they often lamented the soggy quagmire when it was at its wettest.

The reports were true - the prairie looked spectacular. Much more diverse and forb-filled than I remembered from previous visits. Everyone involved in its management deserves major kudos.

In this shot, Purple Coneflower, Echinacea purpurea, and Big Bluestem, Andropogon gerardii, dominate but plenty of other botanical diversity is visible in the scene.

Photo: Dave Nolin

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.

Purple Coneflower is one of the most conspicuous prairie flowers, and it attracts legions of pollinating insects.

We were routinely sidetracked by interesting insects, such as this Delicate Cycnia moth caterpillar, Cycnia tenera. It is a dogbane specialist, and dogbane is closely related to milkweed (which are now considered part of the dogbane family, Apocynaceae). This photo tells a few stories. We can see the toxic white latex seeping from a leaf scar. Relatively few caterpillars can ingest that stuff, but the cycnia has cracked dogbane's chemical code. The fuzzy grayish-brown caterpillar looks nice and fresh. That's because it just molted into its final instar, or growth stage. The cast-off skin of its last stage is to the left. Most caterpillars go through five instars before reaching the final stage. Next stop: Cocoon.

We were pleased to find this beautiful specimen of a Fork-tailed Bush Katydid, Scudderia furcata.The larger katydids are often tame and confiding, and easy to coax onto one's finger. They are attracted to salts, and will rasp off the outer epidermal layer of your skin, as Grace is finding out in this photo. It isn't painful; just a funny nibbling sensation. Note the animal's ears - those dark oval dimples just below the knees on the forelegs.

This was a nice find, indeed, although the backdrop left something to be desired. It is an Orange-spotted Pyrausta, Pyrausta orphisalis, savoring the delights of coyote scat. These colorful day-flying moths resemble small butterflies.

Almost as soon as we entered the prairie, birds grabbed our attention. Squadrons of Bobolinks coursed over the meadow, issuing their softly melodic pink calls. We were constantly serenaded by electric blue Indigo Buntings, incessant motormouths that they are: Fire fire, where where, here here, see see, put it out put it out! The harsh tshacks! of Common Yellowthroats were hurled our way from thickets, the rotund warblers infuriated at our tresspass. I was surprised and pleased to hear a Blue Grosbeak, quite the rarity in this region, singing its rich finchlike song. We later spotted the bird perched atop a sign.

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.

After a while, we were rewarded with excellent looks, and in all detected five singing males. Sedge Wrens often form loose colonies, and if one is found, more will likely be present. In Ohio, they are rare and local breeders, and always a treat to encounter. In our area, at least, the name is a bit of a misnomer. Sedge Wrens most often occur in grasslands - not sedge-filled wetlands - from my experience. The scientific name is Cistothorus platensis, and the genus name roughly translates to "shrub leaper". Where I find them every spring in northern Michigan, that name is apropos - they are often in sedge meadows laced with alder thickets.

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

Rough Boneset, new to Ohio

A group of botanists explores a very special wet meadow in Athens County yesterday. I met up with Brian Riley, Dan Boone, Dave Minney, Andrew Gibson, Rick Gardner, and Susan Nash for a day of botanizing in southeast Ohio. We had a few targets in mind, and the Numero Uno plant was the white specks in the meadow shown above.

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.

The two primary reasons we convened this expedition: Brian Riley, and the plant that he is posing with. Riley, who is an extraordinary field botanist, found Rough Boneset, Eupatorium pilosum, in two off the beaten track Athens County wetlands, and one in nearby Hocking County. I believe Brian found these stations last year, and this was exciting news as this species had never been found in Ohio.

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.

A wet meadow full of Rough Boneset. One of the first big questions involving a new botanical find is whether it is native or not. Many plants are introduced to new areas by people, either intentionally or unintentionally. We all felt that Brian's boneset showed no signs of being a likely introduction. The populations were in areas that would not seem likely places for any sort of intentional introduction, and insofar as we know, Rough Boneset is not in cultivation or sold in the nursery trade. The associated plants in each site were natives, and the seep-fed wet meadows that support the boneset seem to be stable plant communities without evidence of any recent disturbance. Of course, it is possible that some natural agents of dispersal such as birds have helped the plants migrate in recent years, and changing climate is abetting its spread. At this point, that would be hard to conclusively demonstrate, however.

The boneset is an eye-catching plant, but it is undoubtedly quite rare and local. If it were in many sites, someone probably would have picked up on it before now. Bonesets and thoroughworts in the genus Eupatorium do have a tendency to look similar, and chances are only a skilled and aware botanist such as Riley would have recognized this species for what it is. Now that he's found it in Ohio, and we have a distinct search image, it'll be interesting to see if anyone turns up additional populations.

Quite a handsome plant, with broad inflorescences of small white flowers, and comparatively small opposite leaves in ramrod straight stems.

The leaves are sessile; they lack petioles (leaf stems). Note the relatively few coarse rounded teeth on the leaf margins. These sorts of details are important in identifying bonesets.

The specific epithet pilosum in the plant's scientific name refers to hairs, which are quite evident on the stem. Long ago, this species was considered a variety of the Round-leaved Thoroughwort, Eupatorium rotundifolium. After seeing Rough-leaved Boneset in the flesh, and knowing Round-leaved Thoroughwort fairly well, I'd say that such a lump was nonsensical and treating them as separate species is appropriate.

I spent quite a while photographing the bonesets, watching an endless parade of insect pollinators come and go. Bonesets provide a bonanza of nectar, and are especially attractive to beetles. Their fluffy clouds of flowers are conducive to insects that are adapted to clambering around the blooms, rather than rapidly flying from plant to plant or hovering before the flowers. Bonesets provide an inordinately valuable contribution to the plant communities to which they belong, when one factors in their importance to insects.

This handsome little beetle is, I believe, a flower beetle in the genus Macrosiagon. A great many were working over the Rough Bonesets. This group of beetles parasitize various bees and wasps, and as such factor into the infinitely complex ecological web of predator and prey. The beetles, of course, are undoubtedly prey for others. Their role in Nature far transcends colorful eye candy at some pretty boneset flowers.

Scads of Pennsylvania Leatherwing beetles, Chauliognathus pennsylvanicus, were feasting on the bonesets. If one were to dock themselves by a patch of these flowers for an hour or so, I imagine the diversity of insect visitors would be fairly startling.

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

A tiny damsel, larger than life

I took a brief stroll around the work campus this afternoon, between showers. As is almost always the case, I had my camera in tow. The lenses vary, but this time the mega-macro Canon MP-E 65 lens was bolted to the Canon 5D Mark III. I wrote in some detail about this awesome niche lens HERE. The MP-E is not normally my default lens for traipsing about, as it does limit one's options. I like to have it in the pack and close at hand, but have some other more versatile lens attached to the camera.

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

Some more (extremely cool) wasps

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.

There is a smattering of Queen Ann's Lace, Daucus carota, persisting in the prairie. I don't totally begrudge this Eurasian weed its space, as it is a good insect magnet. Not as good as some of the native parsleys, but not bad. Anyway, I was pleased to spot this smallish Hymenopteran busily scarfing up nectar. After a bit of a chase, I pinned down a few passable 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.

A few weeks ago, I found these little adobe jugs stuck to the underside of an American Elm leaf just a stone's throw from the prairie. They are the handiwork of the aforementioned Potter Wasp, and little works of art they are. The female wasp provisions each adobe with paralyzed caterpillars, and then lays an egg within the grisly nursery. Upon hatching, the wasp grub is assured a supply of fresh meat.

Now this is a bona fide beast of a wasp. It is a female Black-and-yellow Mud Dauber, Sceliphron caementarium. Until this day, I had never managed a decent image of one, although they are fairly common. Unless one stakes out a nest that is actively being provisioned, or a muddy spot where nest material is being gathered, you are most likely to encounter a foraging female moving through the plants.

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.

You can see where the expression "wasp-waisted" comes from! In a few seconds the spider was sufficiently comatose and ready for transport to the nest.

These are the multifaceted chambers of a Black-and-yellow Mud Dauber nest. Like the Potter Wasp, it is made from wet earth which is artfully - and laboriously! - fashioned into these fancy crypts. You may have seen these stuck to the eaves of a building. The wasps often select human-built structures for their nest sites.

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

Lytopylus wasp

Photo: Laura Hughes

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.

Well, this animal is also attracted to plants, and it is really tiny. It is a member of the Braconid wasp family, and is in the genus Lytopylus. I did not know such wasps existed until yesterday, when Cheryl Vargas spotted this animal on a trip to a west-central Ohio fen, and tipped me to it. The wasp looks big in this photo, but it wasn't much more than the size of a large mosquito. It is standing atop the still emerging disk flowers of an Orange Coneflower, Rudbeckia fulgida, and when I beamed in on it through the macro lens, I could see it was engaging in very interesting behavior.

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.

Once I returned home, a bit of research led me to her identity, at least to genus (as always, please feel free to correct me on identifications). There are a number of species in the genus Lytopylus, and identifying them to species is beyond me.

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

Sycamore Tussock Moth caterpillars

A stately Sycamore, Platanus occidentalis, rises from rich alluvial soils along a stream. White and brown barked Sycamore trees are easily recognized, and are the most conspicuous tree that defines the channels of creeks and rivers. They also play host to a variety of wildlife, some of which are Sycamore specialists, such as the beautiful Yellow-throated Warbler (at least in this part of the world).

While far less obvious than the aforementioned warbler and much better at hiding, this furry caterpillar is even more of a Sycamore associate than the warbler. It is a Sycamore Tussock Moth caterpillar, Halysidota harrisii. Insofar as I know, Sycamore is its only host plant.

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.

Sycamore Tussocks might be mistaken for the far more wide-ranging Banded Tussock Moth caterpillar, Halysidota tessellaris (above), which feeds on a great variety of plants. However, the caterpillars are easily distinguished by the color of their lashes - whitish to cinnamon-brown in the Sycamore; black in the Banded. Sycamores also have a denser furrier appearance to me, perhaps because their clumps of setae (hairs) are more tightly spaced. So the two species of caterpillars are easily separated. Not so the adult moths, as we shall see.

Sycamore Tussocks are interesting in that they have great color variation - one might think these were two separate species. A crop of eggs can produce caterpillars that range from lemon-yellow to gray to white.

It took a bit of wrestling around with these guys, and a lot of wasted shots, but we eventually managed some nice side by sides. These are handsome beasts by any standard of furry tubular beauty.

As an aside, this is what the underside of a Sycamore Tussock Moth caterpillar looks like. There are eight pairs of legs, as we can clearly see. The orange head of the animal is at the left and there are three pairs of thoracic legs just to the rear. The four pairs of legs in the center of the body are known as anterior prolegs, and the pair at the back of the cat are the anal prolegs.

In tight on the anterior prolegs, which are extremely grippy. These powerhouse gams do the bulk of the work when it comes to securing the caterpillar to twigs or foliage, and their sticking power is astonishingly strong. Just think about a brutal thunderstorm with attendant gale force winds. The caterpillar must do its best to ride out such storms and remain in the tree, and these legs are how they do it.

Katie brought me the caterpillars towards the end of the day, and their photo shoot had to wait until the next day. The three cats were secured in a large jar and well provisioned with fresh Sycamore foliage. Caterpillars essentially do two things - eat, and poop. In Lepidopteran parlance, caterpillar poo is known as frass, and the pile of frass above was generated overnight by the trio.

We go in tight on the frass, just because we can. It looks like tiny rabbit pellets. Believe it or not, there are small animals that mimic the look of frass pellets to perfection, and I just happen to have some good photos of one of these beasts, made last weekend. If not preempted by something cooler, I'll share that critter in the next post. But then, what could possibly be cooler than an animal that is the mirror image of a frass pellet?

I mentioned earlier that Banded and Sycamore Tussock Moth caterpillars are easily told apart, but the moths that they morph into are not. If the moth above came to the attention of most moth enthusiasts, I suspect that they would call it a Banded Tussock Moth, in part because that is the species included in field guides. But the Sycamore Tussock Moth is identical in appearance. Insofar as I know, no one knows how to tell the two apart except by a minute examination of the genitalia, even though it is easy to differentiate the caterpillars. So to be technically accurate, one must pronounce such a moth a "Banded/Sycamore".

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.