Best of BitB 2011

Welcome to the 4th Annual BitB Top 10, where I get to pick my 10 (more or less) favorite photographs of the year. As an insect macrophotographer I still feel like a relative newcomer, although with three seasons under my belt fewer and fewer people seem to be buying it anymore. Granted I’ve learned a lot during that time, but the learning curve is still looking rather steep. I don’t mind—that’s the fun part! With that said, I present a baker’s dozen of my favorite photographs featured here during 2011. I hope they reflect the learnings I’ve had the past year and maybe show some progress over previous years (2009, 2008 and 2010).

One more thing—I’m including a special bonus for the first time in this year’s edition. Each of the photos shown below is linked to a 1680×1120 version that may be freely downloaded for use as wallpaper, printing in calendars, or any other use (as long as it’s personal and non-profit). It’s my way of saying thanks for your readership and support.


From  (posted 8 Jan). I’ve done limited photography with prepared rather than live specimens. However, the recreated aggressive-defensive posture of this greater arid-land katydid (Neobarrettia spinosa)—or “red-eyed devil”—was too striking to pass up. A clean background allows every spine and tooth to be seen with terrifying clarity.


From  (posted 6 Feb). I had never seen a cactus fly until I encountered this Nerius sp. I’m especially fond of the bizzarely-shaped head and un-fly-like spines on the front legs.


From  (posted 17 Feb). This photo of a fungus weevil, Phaenithon semigriseus, is one of the first where I nailed the focus right on the eye at such a magnitude of closeup (~3X) and also got the composition I was looking for. I didn’t notice at the time, but the beetle seems to be “smiling.”


From  (posted 28 Mar). One of the field techniques I’ve been practicing this year is actually holding the plant with the subject in one hand, resting the camera on my wrist and controlling it with the other hand, and manipulating the position of the plant to achieve a desired composition. It’s a difficult technique to master, but the results are worth it. The jumping spider, Euophrys sutrix, represents one of my earliest successful attempts with this technique.


From  (posted 30 Mar). This South American tree fruit weevil looks like it is sitting quite calmly on a branch. In reality, it never stopped crawling while I attempted to photograph it. Crawling subjects are not only difficult to focus on but also almost always have a “bum” leg. I achieved this photo by tracking the beetle through the lens and firing shots as soon as the center focus point flashed, playing a numbers game to ensure that I got at least one with all the legs nicely positioned. I’d have been even happier with this photo if I had not clipped the antennal tip.


From  (posted 4 May). Face shots of predatory insects are hard to resist, and in this one of the fiery searcher beetle, Calosoma scrutator, the angle of the subject to the lighting was perfect for showing off every ridge and tooth in its impressive mandibles.


From  (posted 10 May). I’ve taken plenty of lateral profile shots of tiger beetles, but I like this slightly panned out one especially because of the sense of scale and landscape created by the inclusion of the plantlets and the view over the small rise.


From  (posted 18 May). I found these Edessa meditabunda stink bug eggs on the underside of a soybean leaf in Argentina almost ready to hatch. The developing eye spots in each egg gives the photo a “cute” factor rarely seen in such super close-ups.


From  (posted 15 July). Some of my favorite insect photos are not only those that show the bug in all its glory, but also tell a story about its natural history. This nymphal lichen grasshopper, Trimerotropis saxatilis, is almost invisible when sitting on the lichens that cover the sandstone exposures in its preferred glade habitat. 


From  (posted 23 Aug). I know this is the second beetle face shot I’ve included in the final selections, but it was while photographing this rare Florida metallic tiger beetle, Tetracha floridana, in the middle of the night that I discovered the use of extension tubes to improve the quality of flash lighting (decreased lens to subject distance results in greater apparent light size). This is perhaps one of the best illuminated direct flash photographs that I’ve taken, and I also like the symmetry of the composition.


From  (posted 17 Sep). The three-cornered alfalfa hopper (Spissistilus festinus) is a common pest of alfalfa and soybean in the U.S. However, despite its abundance, I’ve never noticed the bizarre zig-zag pattern of the eyes until I took this photo. Even though both the insect and the background are green, there is sufficient value contrast to create a pleasing composition. Bumping up the ISO and a lower FEC setting prevented overblowing the light greens—easy to do with full flash macrophotography.


From  (posted 4 Oct). This longhorned beetle had settled in for the night on its Ericamera nauseosa host plant, allowing me to use higher ISO and lower shutter speed settings with a hand-held camera to achieve this very pleasing blue sky background, while retaining the sharpness of detail of the subject that comes from full-flash illumination. The blue sky background provides a more pleasing contrast with the colors of this particular beetle and flowers than the black background that is more typically seen with full-flash macrophotography.


From  (19 Dec). An uncommon underside view of these purple tree fungus (Trichaptum biforme) caps and use of flash illumination allows the colors to literally glow against the bright green lichens also growing on the tree. Keeping aperture at a moderate setting allows blurring of the caps further back, adding three-dimensionality to the photo and preventing it from looking ‘flat.’


Well, there you have it, and I hope you’ve enjoyed my selections. Please do tell me if you have a favorite among theses (and if there were other photos posted during 2011 that you think deserved making the final selections).

Copyright © Ted C. MacRae 2011

Peek-A-Boo!

Dissosteira carolina (Carolina grasshopper) | Jersey Co., Illinois

Despite the geographic specificity of its scientific and common names, the Carolina grasshopper (Dissosteira carolina) can be found in every state of the contiguous United States and adjacent provinces of Canada. Its large size, cryptic coloration with yellow hind wings, tendency of males to crepitate during flight (a snapping or crackling sound made by rubbing the under surface of the forewings against the veins of the hind wings), and distinctively chunky nymphs would normally be enough to attract a lot of attention were it not also among the most overwhelmingly ubiquitous of grasshoppers throughout much of its range. I could give all sorts of information about its food habits, migration and dispersal behavior, daily activities, etc., but this would be redundant given the excellent Species Fact Sheet that has been generated for it by the Wyoming Agricultural Experiment Station (Pfidt 1996).

This individual was found in a soybean field in Jersey Co., Illinois. They are extremely wary and perhaps the most difficult-to-approach grasshopper I’ve encountered yet. Considering my particular fascination with oedipodine grasshoppers, I felt compelled to take some photographs—but, my God, there are already a godzillion photos of this species on the web.  I decided to limit myself to this one rather unusual perspective and leave it at that!

REFERENCE:

Pfidt, R. E.  1996. Carolina Grasshopper Dissosteira carolina (Linnaeus). Wyoming Agricultural Experiment Station Bulletin 912, Species Fact Sheet, 4 pp.

Copyright © Ted C. MacRae 2011

Oedipodine Rex

Sandstone glade habitat for Trimerotropis saxatilis | vic. Calico Rock, Arkansas

Ever since my current fascination with band-winged grasshoppers (family Acrididae, subfamily Oedipodinae) began, I have been obsessed with photographing one species above all others—Trimerotropis saxatilis, the lichen grasshopper. Like most species in the group, lichen grasshoppers utilize an interesting survival strategy that I call “conspicuous crypsis”—the use of stunning colors and contrasting markings to help them blend into the mottled and variably-colored environments that they inhabit.  Lichen grasshoppers take this strategy to the extreme, culminating in some individuals with the most gorgeous shade of blue-green in perfect match to the crustose lichens that cover the rock outcroppings of their preferred glade habitats.  In my opinion, they are the kings of the oedipodines!  I have seen them before in past years in the igneous and sandstone glades that dot the Ozark Highlands of southern Missouri.  Crustose lichens abound in these acid environments, providing the perfect backdrop to make invisible these otherwise conspicuous grasshoppers. This past June during a couple of visits to a marvelous sandstone glade complex near Calico Rock in north-central Arkansas I got my wish, and shown here are some of my favorites from the many, many photographs I took during those sessions.

Trimerotropis saxatilis with classic lichen-green coloration.

Lichen grasshoppers are actually quite variably colored—not all individuals exhibit the green coloration for which they are so famous.  Despite this, they are the only member of the genus occurring in the eastern U.S. and, thus, are immediately recognizable.  While they are beautiful in all of their color variations, I cannot lie—it is the green individuals that I constantly find myself admiring the most.  While many other grasshoppers are green, only a handful (themselves members of the same subfamily) exhibit the same stunning shade of blue-green that this one does.  Add to that an abundance of black speckling and contrasting bands, and you’ve got one gorgeous grasshopper.  Yet, for all their overt beauty, they are absolutely impossible to see in their native habitat until they take flight when approached.  Fortunately, their escape flights are short and not terribly erratic—with a little practice it becomes rather easy to track them in flight (aided by their interrupted buzzing crepitation) and watch where they land.  They may not be immediately visible after landing, but with careful study of the landing area they are usually quickly relocated.  Once detected, slow deliberate movements are all that are needed to allow a close approach and a good look (and photographs if desired).

The stunning green contrasts starkly against a dark moss backdrop.

Of course, the problem with ‘conspicuous crypsis’ (or any form of crypsis, for that matter) is that it only works when in the right environment.  I chased the above lichen-colored individual onto this patch of dark moss while trying to photograph it, at which point it became overtly visible.

The mottling of the colors is almost as fascinating as the colors themselves.

As previously mentioned, lichen grasshoppers come in a variety of colors and shades.  While the green individuals may be the most stunning, I was captivated also by the below individual, darker brown and black, with the most beautiful, contrastingly colored orange eyes.  This individual may not blend in as well as the green individuals when sitting on lichen-encrusted rocks; however, its coloration and patterning seem perfectly adapted to the more barren, darkly colored rock exposures.  This helps explain why not all lichen grasshoppers are green—the rock exposures in the glades that they inhabit are not uniformly lichen-encrusted, but rather consist of both encrusted and barren expanses of rock, with diverse coloration being a result of multiple and sometimes conflicting selective pressures.

A darker brownish individual with spectacular orange eyes.

A third individual, shown in the photograph below, resembles the second in that it is more brown than green.  However, the base coloration is lighter with greater contrast to the dark bands.  Like the second individual the eyes are spectacular orange, but it also exhibits a green shading on the back of the head behind the eyes not seen in the second individual.

Another brownish individual, this one more contrastingly marked.

Not only did I find the adults, but I also found a rather young nymph that certainly represents this species (I’m guessing maybe 3rd instar based on the degree of wing pad development).  This nymph exhibits the same stunning green coloration that the first individual above shows, and its fortuitous occurrence on both lichen-encrusted and (relatively) barren rocks provide an excellent demonstration of the effectiveness of its coloration in achieving crypsis—now you see me…

The lichen-colored nymph is easily seen against barren rock...

…now you don’t!

...but blends in marvelously amongst the lichens.

Copyright © Ted C. MacRae 2011

A “Giant” Pygmy

Not long ago, I got an email from grasshopper expert David J. Ferguson confirming my identification of  (and also encouraging my recent fascination with band-winged grasshoppers (family Acrididae, subfamily Oedepodinae) and their marvelously cryptic nymphs).  He suggested that I might also find the “toad lubbers” (family Romaleidae) and pygmy grasshoppers (family Tetrigidae) interesting, since they too have many of those qualities I was finding attractive in band-winged nymphs, only on a very small scale.  It was a prescient comment, as I’d already started taking notice of the pygmies and even photographed one before ever getting his email.

Tettigidea lateralis | Shaw Nature Reserve, Missouri.

I take this individual to represent Tettigidea lateralis (black-sided pygmy grasshopper), which I saw at Shaw Nature Reserve during my May search for .  Actually, I’m not sure I would have even noticed this individual, as I walked along the trail going from open woodland through dry dolomite glade, had it not actually been sitting on my net rim.  I haven’t studied pygmies all that much, other than to note that they seem common around streams and other wet areas and are usually quite small.  This one, however, at close to 15mm in length seemed positively gigantic!  I placed it on the barren dolomite along the trail, expecting it to flee immediately.  Instead it just sat there—begging me to photograph it, so I did.

Bold, white femoral markings contrast nicely with its otherwise marvelously cryptic coloration.

This one appears to be a female with a short pronotum, but I can’t tell if it is an adult with short wings or still a nymph (it was certainly large enough to be an adult!).  Either way, I’m interested in the function of the bright white femoral marking on what is otherwise a very cryptically colored individual.

Copyright © Ted C. MacRae 2011

Pardalophora phoenicoptera – Orange-winged grasshopper

For some reason, I’ve found myself increasingly fascinated with certain grasshoppers—not just any grasshoppers, but band-winged grasshoppers (family Acrididae, subfamily Oedepodinae).  And not just band-winged grasshoppers, but band-winged grasshopper nymphs.  It began last year when I found adults and nymphs of Trimerotropis latifasciata in the Glass Mountains of northwestern Oklahoma.  I believe it has something to do with the combination of their frequent association with the same habitats where I look for my beloved tiger beetles and their marvelously cryptic coloration.  Adults themselves are cryptic enough—that is, until they flash their brightly colored hind wings, but the nymphs are positively invisible until they move.  Moreover, many species show a wonderful range of intraspecific diversity in their crypsis—Ronald Reagan may have thought every redwood tree looked the same, but when you’ve seen one band-winged grasshopper nymph, you most certainly have not seen them all.


These two band-winged nymphs were seen at St. Joe State Park (St. Francois Co., Missouri) in the vast central “sand flats” of the park (actually waste areas of crushed limestone tailings left from lead mining operations during the previous century).  At first I assumed they each represented a different species, but based on comments at BugGuide I take both of them to represent Pardalophora phoenicoptera (orange-winged grasshopper)—distinguished from Xanthippus by having only one notch in the pronotal crest and unusual amongst most grasshoppers in that the winter is passed as a nymph rather than egg.  This leads to well-developed nymphs at the beginning of spring and adults much earlier in the season than many other grasshoppers.  These photos were taken on April 28, and the size of the wing pads suggests they are not quite full-grown yet, maybe 3rd or 4th instars.  Acridoid aficionado David J. Ferguson has found this species in the Ozarks on rocky/gravelly hilltops (e.g., “cedar glades”) and on gravelly or stable sandy slopes in sunny openings in Oklahoma. He places the species (particularly the green ones) high on his favorite hopper list, and I’d have to say I agree with him (so far).

One of these days, I’m going to find and photograph the king of all green oedepodines—Trimerotropis saxatilis!

Update 6/8/11: Dave Ferguson has kindly confirmed the ID, writing:

…yes these are identified correctly.  Assuming 5 instars, they look like 4th (where there are 6 instars, numbers 4 and 5 look a lot alike).

Copyright © Ted C. MacRae 2011

Saltatorial sidetracks

One thing I’ve realized during these past several years of fall collecting is that there are more than just tiger beetles to capture my interest as the field season enters its final days.  The late season floral burst of goldenrods (Solidago spp.) and tall thoroughwort (Eupatorium altissimum) brings forth a multitude of bees, flies, wasps, and soldier beetles.  Megacyllene robiniae, the locust borer (family Cerambycidae), is also a pleasant, if not pedestrian sight on the goldenrod as well, but if one is lucky to find goldenrod near a patch of Amorpha fruticosa (indigo bush), then its larger, more boldly marked and infinitely more exciting congener M. decora (indigo borer) might also be seen.  Nothing, however, seems to match the diversity and abundance during fall of the great order Orthoptera – grasshoppers, katydids, and crickets.  This is particularly true in the Ozark glades and Great Plains grasslands where I’ve spent the majority of my fall collecting time.  Perhaps it is because of their size – for the most part they are relatively large insects compared to the beetles I normally study, or maybe it is their pervasive reliance on sound – singing in the grass, rasping in the trees, snapping their wings in flight.  Bold and conspicuous, they demand attention.

Increasingly, I’m finding these fall hoppers harder and harder to resist, especially grasshoppers of the family Acrididae.  Until now I don’t think I’ve given grasshoppers their due respect – compared to my beetles they always seemed so… primitive.  No horns, no jeweled, metallic sculpturing, no over-sized jaws, no unique morphological specializations of any kind other than enlarged, saltatorial (modified for jumping) hind legs – they sport the quintessential ‘general’ insect body plan (open up any college introductory entomology textbook, and what do you see illustrated in the general morphology chapter… a grasshopper!).  Even their movements seemed to me somehow mechanical and robotic.  I always brushed them off as just basic insects, unrefined and uninteresting.

Of course, they are anything but uninteresting – in fact, orthopterans as a whole are among the most popular of insect groups if the number of recently published field guides is any indication.  One of these is The Grasshoppers (Orthoptera: Acrididae and Romaleidae) of Nebraska (2008), authored by Matthew L. Brust and colleagues, and a copy of which I received as a gift from the senior author during my recent collecting trip to Nebraska and surrounding areas.  According to this book, the grasshopper in these photographs is Hippiscus ocelote – the wrinkled grasshopper, a large, handsomely robust species distinguished by the single cut in the pronotum and its surface sculpturing, the orange hind tibia, and the triple-banded and basally blue inner surface of the hind femur.  The species is generally brownish throughout, but this particular individual – seen in the White River Hills of southwestern Missouri in early September – sported a decidedly reddish head and pronotum that contrasted beautifully with its spotted wings and forced me to stop searching for tiger beetles and spend some time photographing it.

There are many reasons why I should not let myself get interested in grasshoppers – they’re big and take up a lot of space (a premium in most private collections such as mine), and by any standard my interests are already spread too thin.  Still, I think it is better to have too many interests than not enough, and a Schmidt box or two full of some of the more interesting grasshoppers that I’ve encountered – properly curated and identified – wouldn’t take too much away from my beetle efforts.  I already have a few specimens of Trimerotropis saxatilis (lichen grasshopper) from Missouri’s igneous glades and the related T. latifasciata (broad-banded grasshopper) from Oklahoma’s Glass Mountains, so a small assortment of other notable species in addition to them couldn’t hurt, right?

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/16-f/20), Canon MT-24EX flash (1/2 ratio) w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCE:

Brust, M. L., W. W. Hoback and R. J. Wright.  2008. The Grasshoppers (Orthoptera: Acrididae and Romaleidae) of Nebraska.  University of Nebraksa-Lincoln Extension, 138 pp.

Copyright © Ted C. MacRae 2010

What’s more difficult to see…

…than a Trimerotropis latifasciata (broad-banded grasshopper) adult on lichen-encrusted clay exposures?


Answer: A T. latifasciata nymph on lichen-encrusted clay exposures.


My thanks to David J. Ferguson for confirming my initial ID as a species of Trimerotropis and provisionally placing these individuals as T. latifasciata.  Of course, I’m not at all an expert in grasshopper identification, but I recognized these individuals, found atop the red, flat-topped mesa of Gloss Mountain State Park in northwestern Oklahoma, for their great similarity to T. saxatilis (lichen grasshopper), a striking, more greenish species (at least here in Missouri) that I had hoped to but did not see during my visit to Lichen Glade Natural Area back in late May (it may have been too early in the season for them).  At first I thought these individuals might represent that species, considering the abundance of lichens that encrusted the clay exposures atop the mesa.  However, according to David the red hind tibia (seen in the photo below of a different adult – sans left front leg), longer wings, occurrence on clay (rather than rock or sand), and location in the Great Plains make T. latifasciata the most tenable choice.

Like T. saxatilis and other species of the genus, T. latifasciata provides a marvelous example of the use of camouflage (i.e., blending in with surroundings) – a form of crypsis – to avoid detection by predators.  Finding this species only strengthens my desire to find (and photograph) T. saxatilis – speckled green, white and black – amidst the green lichens that encrust the red igneous outcroppings of the St. Francois Mountains some 100 miles south of St. Louis.

Photo Details: Canon 50D w/ 100mm macro lens, (ISO 100, 1/250 sec, f/18-20, Canon MT-24EX flash (1/4 ratio) w/ Sto-Fen diffusers, and typical post-processing (levels, minor cropping, unsharp mask).

Copyright © Ted C. MacRae 2010

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The Loess Hills in Missouri

The term Mountains in Miniature is the most expressive one to describe these bluffs. They have all the irregularity in shape, and in valleys that mountains have, they have no rocks and rarely timber. – Thaddeus Culbertson, missionary, 1852


One of the things I enjoy most about the natural history of Missouri is its diversity. Lying in the middle of the North American continent, it is here where the eastern deciduous forest yields to the western grasslands. Coinciding with this transition between two great biomes is a complex intersection of landforms – the northern plains, recently scoured by glaciers; the southeastern lowlands, where the great Mississippi River embayment reaches its northern extent; the Ozark Highlands, whose craggy old rocks comprise the only major landform elevation between the Appalachian and Rocky Mountains; and the eastern realm of the vast Great Plains. This nexus of east and west, of north and south, of lowlands and highlands, has given rise to a rich diversity of natural communities – 85 in all according to Paul Nelson (2005, Terrestrial Natural Communities of Missouri). Despite the overwhelming changes wrought upon Missouri’s landscape during the past 200 years, passable examples of most of these communities still exist in many parts of the state and provide a glimpse of Missouri’s rich natural heritage.

Last month I talked about the critically imperiled sand prairie community in extreme southeast Missouri. This month, we travel 500 miles to the distant northwestern corner of the state to visit another critically imperiled community – the dry loess prairie. These communities are confined to thin slivers of bluff top along the Missouri River in Atchison and Holt Counties. The bluffs on which they lie are themselves part of a unique landform called the Loess Hills. Like the sand prairies of the southeastern lowlands, this angular landscape owes its birth to the glacial advances of the Pleistocene epoch (2.5 million to 10,000 years ago), when streams of meltwater – swollen and heavily laden with finely ground sediments (i.e., glacial “flour”) – filled river valleys throughout the Midwest during Pleistocene summers. Brutal cold during winter reduced these flows to a trickle, allowing the prevailing westerly winds to pick up the sediments, left high and dry, and drop them on leeward upland surfaces across Iowa and northern Missouri. The thickest deposits occurred along the abrupt eastern border of the Missouri River valley – at least 60 feet deep, and in places up to 200 feet. Loess (pronounced “luss”) is a homogeneous, fine-grained, quartz silt – undisturbed it is highly cohesive and able to stand in near vertical bluffs. It is also extremely prone to erosion, and as a result for 10,000 years now the forces of water have reshaped the Loess Hills into the landform we see today. Loess itself is not rare – thick deposits can be found in many parts of the world and over thousands of square miles across the Midwest. It is here, however, along the western edge of Iowa and northern Missouri – and nowhere else in North America – where loess deposits are deep enough and extensive enough to obliterate any influence by the underlying bedrock and dictate the form of the landscape.

It is this form that makes the Loess Hills so unique. The depth of the soil, its cohesiveness, its natural tendency to slump on steep slopes and sheer in vertical planes, and the action of water over the past several millenia have created a landscape of narrow undulating ridges flanked by steep slopes and numerous side spurs, intricate drainages with sharply cut gullies, and long, narrow terraces called “catsteps” cutting across the steep upper hillsides. It’s a sharp, angular, corrugated landscape, stretching 200 miles north and south in a narrow band of varying width from north of Souix City, Iowa, to its southern terminus in northwestern Missouri. Its western boundary is sharply delimited by the Missouri River valley, where lateral erosion (now halted by channelization of the river) and vertical sheering have created precipitous bluff faces. The eastern boundary is harder to delimit and is dependent upon the thickness of the loess. Deposits that fall below 60 feet in depth are unable to mask and reshape the rolling terrain of the eroded glacial till lying beneath. In general, this happens at distances of only 3 to 10 miles from the western edge of the landform.

Its southern terminus in Missouri, however, is the most arbitrary boundary. Discontinuous patches of deep loess terrain do occur as far south as Kansas City, but the dry hilltop prairies, common in the north, are gradually replaced by woodland in the south and disappear completely just north of St. Joseph. It is this interdigitation of two great biomes – the great deciduous forest to the east, and the expansive grasslands stretching far to the west – that give the Loess Hills such a fascinating natural history. This is due as much to the physical character of the Loess Hills themselves as to their ecotonal position at the center of the continent. Rapid drainage of rainwater off the steep slopes combines with direct sun and prevailing southwesterly summer winds to create very dry conditions on hilltops and south and west facing slopes, especially on the steeper slopes along the landform’s western edge. Such xeric conditions favor the growth of more drought-tolerant species derived from the western grasslands. North and east facing slopes and valley floors, protected from direct sun and drying winds, are able to retain more moisture, favoring the growth of woody plant species more common in the eastern forests. Seasonal moisture also shows a north-south gradient, with southern latitudes receiving higher annual rainfall totals that also favors the growth of woody plants, while the lower rainfall totals further north result in larger, more expansive grassland habitats. The steep slopes and rapid drainage create much more xeric conditions than those found further south in the flat to rolling terrain of the unglaciated Osage Plain, resulting in a more drought-tolerant mixed-grass prairie rather than the tallgrass prairie of western and southwestern Missouri. The distribution patterns of prairie versus woodland are dynamic and ever-changing, influenced by both natural and anthropogenic processes. Climatic conditions over much of the Loess Hills are capable of supporting either community type, both of which repeatedly expand and shrink as the balance tips in favor of one versus the other. In the past, the major influence was shifting periods of greater or lesser rainfall. During drier periods, grasslands expanded and woodlands shrank, finding refuge in only the moistest streamside habitats. Wetter periods allowed woody plants to migrate out of the valleys and up the slopes, especially those facing north and east. One particular very dry “hypsithermal” began about 9,000 years ago and lasted for several thousand years. Tallgrass prairies expanded as far east as present day Ohio, and todays tallgrass praires in the eastern Great Plains were invaded by even more drought-tolerant species from the shortgrass prairies further west. Eventually the hypsithermal abated, moisture levels increased, and the grasslands retreated in the face of the advanding forest. Not all of the drought-tolerant species were driven back, however, and scattered populations of these “hypsithermal relicts” still remain on locally dry sites far to the east of their normal range of distribution. Conspicuous examples of such in Missouri’s Loess Hills are soapweed yucca (Yucca glauca var. glauca) and the leafless-appearing skeletonweed (Lygodesmia juncea) (plant above, flower right). Both of these plants are normally found further west in the mixed grass prairies of the western Great Plains but are considered endangered in Missouri due to the great rarity of the dry loess prairies on which their survival depends. (Incidentally, note the crab spider legs extending from behind the petals of the skeletonweed flower). In total, more than a dozen plant species occurring in Missouri’s dry loess prairies are listed as species of conservation concern, along with one reptile (Great Plains skink) and one mammal (Plains pocket mouse).

As is typical, the insect fauna of the Loess Hills has been far less studied than its plants, but many of the species that have been documented in its prairies also show affinity to the Great Plains fauna. Both soapweed and skeletonweed have insect associates that rely exclusively on these hosts for reproduction, and as a result they are also highly restricted in Missouri. Evidence of one of these – a tiny cynipid wasp (Anistrophus pisum) that forms small spherical galls on the stems of skeletonweed – can be seen in the photo above. However, my purpose for visiting the Loess Hills this summer was to look for the rare and possibly endangered tiger beetle, Cicindela celeripes (see this post). Cicindela celeripes has not yet been recorded from Missouri but is known to occur in the Loess Hills of southwestern Iowa, and while I have not succeeded in finding it (yet!) I did observe several adults of this unusual May beetle species, Phyllophaga lanceolata. This May beetle occurs throughout the Great Plains in shortgrass prairie communities. Larvae feed in the soil on roots of grasses and other plants, while adults feed above ground on flowers and foliage. The heavy-bodied adults are unusual in the genus due to their conspicuous covering of scales (most species of Phyllophaga are glabrous or with sparsely scattered and indistinct setae) and by being active during the day. They are also relatively poorer fliers and are thus usually observed moving about on foot – as seen with this individual who was found on bare soil below a vertical cut. This snakeweed grasshopper (Hesperotettix viridis, ID by Eric R. Eaton) is another species more typically seen in the western United States, although populations have been found from across the continent. Preferred host plants include a variety of asteraceous shrubs, but as suggested by the common name snakeweeds (Xanthocephalum spp.) are highly preferred and account for its greater abundance in the west. Populations in northern and eastern portions of its range, which would include northern Missouri, are considered subspecies pratensis, while the more southern and western populations are considered the nominotypical subspecies. Interestingly (and unlike many grasshoppers), this species is considered beneficial by ranchers, since the plants on which it prefers to feed are either poisonous to livestock or offer little nutritional value while competing with more desirable forage plants for soil moisture. While exploring the upper slopes, I encountered sporadic plants of two of Missouri’s more interesting species of milkweed – whorled milkweed (Asclepias verticillata) and green milkweed (Asclepias viridiflora), raising my hopes that I might encounter one of the many Great Plains species of milkweed beetles (genus Tetraopes). However, the only species I observed was the common milkweed beetle, Tetraopes tetrophthalmus, which occurs broadly across eastern North America on the equally broadly distributed common milkweed (Asclepias syriaca).

It is a familiar refrain, but Missouri’s dry loess hill prairie communities are critically endangered. Historically, these communities were probably never as well developed as those further north, and only a few small remnants remain today due to significant woody encroachment following decades of fire suppression. Much of this encroachment has occurred in the past 50 years – Heinman (Woody Plant Invasion of the Loess Hill Bluff Prairies. M. A. Thesis, University of Nebraska at Omaha, 1982) used aerial photographs to show a 66 percent encroachment of shrubs and trees into the loess hill mixed-grass prairies between 1940 and 1981. Additional threats include overgrazing, erosion, invasion by exotic plant species and homesite development. Fewer than 50 acres of native dry loess hill prairie remain in Missouri – only half of which are now in conservation ownership. The majority of these can be found at Star School Hill Praire and Brickyard Hill Conservation Areas in Atchison County and at McCormack Conservation Area just to the south in Holt County. Controlled burning and selective cutting are being used at these sites to control woody plant invasions, but even these management techniques present challenges. Spring burns have been shown to promote the growth of big bluestem (Andropogon gerardii), which could allow it to encroach drier areas where mid-grasses such as little bluestem (Schizachyrium scoparium) and sideoats grama (Bouteloua curtipendula) typically dominate (Rushin 2005). Increases in tall grasses could shade out and eliminate some of the rarer low-growing forbs such as downy painted cup (Castilleja sessiliflora), locoweed (Oxytropis lambertii) and low milkvetch (Astragalus lotiflorus). Fall or winter burns may be more beneficial to forbs because the plants are allowed to complete flowering and seed set, but the steep slopes on which these communities occur make erosion a potential concern. Clearly, all factors must be considered when designing management plans for this rare and significant slice of Missouri’s natural heritage.


In addition to the links and references provided above, I highly recommend Fragile Giants: A Natural History of the Loess Hills, by Cornelia F. Mutel (1989). All of the above photographs were taken at Star School Hill Prairie Conservation Area on July 12, 2008. Additional photographs of Loess Hill habitats in extreme southwestern Iowa appeared in my earlier post, The hunt for Cicindela celeripes. The plants shown in photographs 5-7 are purple praire clover (Dalea purpurea), white prairie clover (D. candida), and lead plant (Amorpha canescens), respectively. Lastly, I would like to apologize for the length of this post – a consequence of my inability to temper my utter fascination with the natural world and desire to understand the depths its connectedness.