glades

Magnificently Monstrous Muscomorphs

/ Ted C. MacRae / 9 Comments

I suppose tiger beetles have gotten more than their fair share of attention here lately, so for this post I thought I’d highlight insects of a completely different group – flies! Admittedly, as a coleopterist, I tend to view flies with much the same disdain as your average insect non-enthusiast – as pesky, pestiferous vermin worthy of little more attention than a decisive swat. I don’t begrudge them their amazing diversity – at ~100,000 described species worldwide, they are strong contenders with the Lepidoptera and Hymenoptera as the second largest order of insects (of course, you need all three of these orders combined to match the diversity of the Coleoptera). I am also prepared to accept that they may well represent, at least morphologically, the pinnacle of insect evolution (a position that a few hymenopterists I know might argue with) due to their amazing flight capabilities and the morphological adaptations they have developed for such. These include the development of aristate antennae for detecting wind speed, the conversion of the second pair of wings into stabilizing organs (halteres), and the ability to beat the remaining pair of wings at incomprehensible rates – up to 1,000 times per second in some very small midges (even more baffling when one considers that the wing “beat” is actually just a passive result of rhythmic distortions of the thoracic box). I even acknowledge that the vast majority of fly species are not even pests, living their lives innocuously as herbivores, scavenging organic matter that nothing else wants, and preying upon or parasitizing other insects, including important agricultural pests. Still, flies bug me – mosquitoes prevent me from sleeping under the stars without a tent, deer flies drone around my head incessantly while I’m trying to stalk an elusive tiger beetle, stable flies trick me into assuming they are just another house fly (until they bite me!), house flies (the real ones) rudely land on my sandwich with their filthy feet, and eye gnats insist on committing hary kary in my eyes as I walk the trails (I won’t mention their other common name, derived from their habit of clustering around exposed canid genitalia).

There is, however, one group of flies that possess “cool factor” rivaling that of even the most popular insect groups – robber flies and their kin. I’ve always picked them up as an aside, even sending them off for authoritative ID and constructing an inventory of the species in my collection. The brute of a fly pictured here is not a true robber fly, but in the related family Mydidae. Mydus clavatus can be recognized easily in the field by its large size and distinctive black coloration with red/orange on top of the 2nd abdominal segment. Presumably this is an example of Batesian mimicry modeled upon spider wasps (family Pompilidae) in the genus Anoplius. This mimicry allows them to fly rather boldly in the open and is so persuasive that it can not only fool the casual observer, but even the most knowledgable of entomologists might be loathe to handle it despite knowing better. Although common across the eastern U.S., aspects of its life history are poorly understood. Adults have been reported to be predators of other insects, but apparently there are some doubts about the veracity of such reports. Patrick Coin of BugGuide has observed adults (males?) taking nectar from flowers and has suggested that reports of predation by adults might have been an erroneous assumption due to their relation and resemblance to robber flies. Larvae are reported to be predaceous on woodboring beetle larvae, and I have reared adults of this species from a dead sycamore (Platanus occidentalis) stump in southern Missouri that was infested with mature larvae of the large buprestid species, Texania campestris. This habit is similar to robber flies of the genus Laphria, which mimic bumble bees and carpenter bees.

In Greek mythology, Promachos (Προμαχοε) was “the champion” or one “who leads in battle” – an appropriate generic name for the so-called “giant robber flies” of the genus Promachus. These large flies are dominant and fearless predators that will capture just about any flying insect – even adult dragonflies. There are three species of Promachus in the eastern U.S. that exhibit the yellow and black tiger striping of the abdomen seen in this individual, identified as a female Promachus hinei by Herschel Raney at BugGuide due to its reddish femora and occurrence in the central U.S. Promachus rufipes is similar but has black femora with distinctly orangish tibiae and is more common in the southeastern U.S., whereas P. vertebratus has more muted two-toned legs with smaller dark areas dorsally on the abdominal segments and is more common in the northern states. Additional species occur in the region but lack the tiger striping of the abdomen, and even more species occur in the western U.S. Members of this genus generally lay their eggs on the ground near grass roots, and the larvae burrow into soil after hatching and feed on soil insects, roots, and decaying matter before pupating within the soil in an unlined cell.

During my recent trip to Nebraska I encountered this related robber fly genus Proctacanthus, also determined by Herschel provisionally as P. milbertii. These large robber flies with a prominent beard are similar in habit to Promachus species, laying their eggs in crevices in soil and the larvae feeding on soil insects, roots, and decaying plant matter. Proctacanthus milbertii is a late season species that occurs across much of the U.S. and reportedly loves butterflies. However, Joern & Rudd (1982), in studying predation by this species in western Nebraska (where the individual pictured here was photographed) found that grasshoppers made up 94% of the prey captured by this species. Interestingly, nearly all of the remaining prey captures were other P. milbertii, which was carefully verified as such since mating postures can be easily mistaken for prey handling positions. Grasshopper prey species taken by this species were most strongly influenced by availability rather than size, suggesting that even the largest grasshopper species could be captured as easily as smaller species – a testament to the ferocity of this robber fly.

Another family of flies modestly related to robber flies and also ranking high in “cool factor” are the bee flies (family Bombyliidae). The scaly bee fly, Lepidophora lepidocera (ID confirmed by Joel Kits at BugGuide), is a particularly attractive member of the family. The distinctive, hunch-backed shape of this southern U.S. species is shared with the more northern L. lutea, from which it is distinguished by having pale scales only on the 5th abdominal segment and not on the 4th also. Most bee flies are presumbably mimics of – yes – bees; however, the species in this genus might actually be mimics of robber flies instead. Adults are most often seen taking nectar from flowers – this individual was taken on flowers of tall boneset (Eupatorium altissimum). Larvae are characterized by Sivinski et al. (1999) as kleptoparasites on the provisions of solitary wasps in the families Vespidae and Sphecidae – meaning that the larva does not parasitize wasp larvae directly, but instead usurpes the nest provisions on which the wasp larvae were supposed to feed. The little thieves!

Cicindela scutellaris lecontei x scutellaris unicolor intergrades in southeast Missouri

/ Ted C. MacRae / 8 Comments

An individual from Sand Prairie Conservation Area. Note the uniform blue-gray coloration and complete lack of maculations, making this individual indistinguishable from true unicolor.Cicindela scutellaris (festive tiger beetle) is widely distributed in the U.S., having been recorded from most areas east of the Rocky Mountains except Appalachia, the lower Mississippi River delta, and south Florida. Within this range, the species occupies deep, dry sand habitats without standing water. It is often found in the company of Cicindela formosa (big sand tiger beetle), whose range largely coincides with that of C. scutellaris (except the southeastern Coastal Plain). More than any other North American Cicindela, populations of this species show extraordinary variability in color across its range of distribution. Seven geographically recognizable subspecies are generally accepted, with considerable variation evident within some of these and along zones of contact between them.

An individual from further south on the Sikeston Ridge (~20 mi S of Sand Prairie Conservation Area). Note the generally blue-green coloration as in unicolor, but it also exhibits fairly well developed maculations and a suffusion of maroon color on the elytra - distinct influences from subspecies lecontei.The greatest portion of the species’ range is occupied by nominotypical populations in the Great Plains and subspecies lecontei in the Midwest and northeast. Similar to what I’ve noted in previous posts for other species, a broad zone of intergradation between these two subspecies occurs along the upper Missouri River. Other subspecies occupy more limited ranges along the upper Atlantic Coast (rugifrons), southeastern Coastal Plain (unicolor), eastern Texas and adjacent areas of northwestern Louisiana and southwestern Arkansas (rugata), and north-central Texas (flavoviridis), and the highly restricted and disjunct yampae is found only in a small area of northwestern Colorado. Populations in the upper Midwest and Canadian prairie are sometimes regarded as distinct from lecontei (designated as subspecies criddlei) due to their broadly coalesced marginal elyral maculations, and an apparently disjunct population of small, blue individuals in south Texas may also be regarded as subspecifically distinct.

Another individual from Sand Prairie Conservation Area. It is similar to the unicolor-type individual in Photo 1 but also exhibits small maculations derived from its lecontei influence.Although Missouri lies well within the boundaries of its range, this species has been found in only three widely-separated parts of the state – near the Missouri River in the northwest part of the state, near the Mississippi River in the extreme northeast corner, and in the southeastern lowlands (formally known as the Mississippi River Alluvial Basin). The two northern Missouri populations are assignable to and typical of lecontei, with their uniform dull maroon to olive green coloration and continuous to near-continuous ivory-colored border around the outer edge of the elytra. Additional dry sand habitats occur along the lower Missouri River in central and east-central Missouri and along some of the larger rivers that drain the Ozark Highlands; however, this species has not been located in these habitats despite their apparent suitability and occurrence of C. formosa with which it frequently co-occurs. The reasons for this distributional gap between the northern and southern populations – some 400 miles in width – remain a mystery. The southeastern Missouri population is not clearly assignable to any subspecies, apparently representing an intergrade between lecontei to the north and unicolor to the south. Accordingly, individuals from this area are known by the unwieldy appellative “Cicindela scutellaris lecontei x scutellaris unicolor intergrade.” Pearson et al. (2005) states that intergrades between lecontei and unicolor are evident only in northern “Missouri” (an obvious error for Mississippi) and Tennessee. Thus, the existence of intergrades in southeastern Missouri suggests that the zone of intergradation extends further north than previously realized.

A second individual from ~20 mi S of Sand Prairie Conservation Area. Similar to the individual in Photo 2 except with smaller maculations. Note the gorgeous suffusion of maroon, especially on head and pronotum - a spectacular individual.Prior to this season, I had located two main population centers in the southeastern lowlands – one at Holly Ridge Conservation Area in Stoddard County, and another at Sand Pond Conservation Area in Ripley County. Holly Ridge is located on Crowley’s Ridge – an erosional remnant of Tertiary sand and aggregate sediments left behind by the late Pleistocene glacial meltwaters whose scouring action formed the surrounding lowlands, while the sandy sediments at Sand Pond were deposited west of Crowley’s Ridge along the southeastern escarpment of the Ozark Highlands during that same period. These erosional and depositional events created the deep, dry sand habitats that Cicindela scutellaris requires. I had known also about the Sikeston Sand Ridge further to the east – another erosional remnant of Tertiary sands deposited by the ancient Ohio River – but had not explored it closely until this season when I initiated my surveys at Sand Prairie Conservation Area. I expected Cicindela scutellaris might occur here, and in my first fall visit in early September I found two individuals in the sand barrens (alongside Cicindela formosa). Another individual was seen here in early October, but more robust populations were observed at a small, high-quality sand prairie remnant (last photo) further to the south along the Sikeston Ridge, and around eroded sand barrens behind private residences still further to the south. Clearly, the species is well-established in the southeastern lowlands wherever open dry sand habitats can be found.

Sand prairie habitat for Cicindela scutellaris in southeast Missouri. Note the well-spaced clumps of grass, in this case splitbeard bluestem.The individuals shown here exemplify the range of variation exhibited by Cicindela scutellaris populations in southeast Missouri. They greatly resemble subspecies unicolor by their uniform shiny blue-green coloration. Indeed, the individual in the first photo might well be classified as such due to the complete absence of white maculations along the elytral border. Most individuals, however, show varying development of such maculations, ranging from small disconneted spots to the more developed apical “C”-shaped mark – clearly an influence from subspecies lecontei. Another apparent lecontei influence is the suffusion of wine-red or maroon coloration that can be seen on the head, pronotum, and elytra of the individuals in photos 2 and 4. These characters make this population divergent from the typically monochromic unicolor (as its name suggests). Because of their bright green coloration and white maculations, individuals in this population greatly resemble subspecies rugifrons, but that subspecies is limited to the northern Atlantic seaboard. They also resemble the common and widespread Cicindela sexguttata (six-spotted tiger beetle) but can be distinguished from that species by the more noticeably domed profile of the elytra, rounded rather than tapered elytral apex, and dark labrum of the female (both sexes of C. sexguttata have a white labrum).

There is one additional sand ridge in Missouri’s southeastern lowlands – the Malden Ridge. This sand ridge occurs south of Crowley’s Ridge and is much smaller than the Sikeston Ridge. No significant remnant habitats remain on the Malden Ridge, but it is possible that sufficient areas of open sand remain that might support populations of C. scutellaris. Determining whether this is true will require some time studying Google Earth and even more time on the ground to search them out. If they do exist, however, it will be interesting to see what level of influence by lecontei is exhibited in this most southerly of Missouri populations. Only spring will tell!

Happy Halloween!

/ Ted C. MacRae / 22 Comments
are-gee-OH-pee our-ON-tea-uhArgiope aurantia

Those who think scientific names are too complicated have the following dizzying array of common names to choose from for this species: black and yellow garden spider; black and yellow argiope; yellow garden spider, yellow garden argiope; yellow garden orbweaver; golden garden spider; golden argiope; golden orbweaver; writing spider; scribbler; corn spider. Or instead, just say Argiope aurantia (are-gee-OH-pee our-ON-tea-uh) – it is unambiguous and will make you sound intelligent.

Large females are commonly encountered in late summer and early fall. This fine lady was photographed 7 September 2008 at Victoria Glades Natural Area in Jefferson County, Missouri. Quite coincidentally, North America’s tarantulas (genus Aphonopelma, represented in Missouri by A. hentzi) reach their natural northeastern limit of distribution in this very glade complex, located ~30 miles south of St. Louis.

There are five North American species of Argiope, of which two occur broadly across the eastern U.S. Argiope aurantia can be distinguished from Argiope trifasciata (banded garden spider/argiope/orbweaver) by the zig-zag pattern of the stabilimentum of the former and the transversely striped abdomen and spotted legs of the latter.

Despite its name, the function of the stabilimentum (reinforced area in the middle of the web) remains controversial. The idea that it somehow adds stability to the web is not given much credence today. A visual function seems much more plausible, especially when considering that only diurnal spiders make such structures. Possibilities include camoflauge for predator avoidance, the seemingly opposite idea of increased visibility to prevent accidental destruction of the web by birds or large animals, and even prey attraction through enhanced reflection of ultraviolet light. Stabilimenta in different spider lineages probably evolved independently and may have different or even multiple functions.

Dicerca pugionata

/ Ted C. MacRae / 2 Comments

In my recent post, Glades of Jefferson County, I discussed the occurrence on these glades of the strikingly beautiful Dicerca pugionata, a jewel beetle that breeds in the scraggly ninebark plants growing along the glades’ moist toeslopes. Adults of this species are normally encountered only during March/April and then again during September/October, so I wasn’t able to photograph them during this recent visit. I did, however, have on hand some slides that I took back in April 1987 – one of which has been scanned and added here as well as to the original post immediately above the photograph of the beetle’s host plant. The full-sized version of the scan is slightly lacking in clarity, nevertheless I think you’ll agree that its brilliant coppery color, distinctive dorsal sculpturing, and reddish elytral apices make this quite a lovely beetle!

Glades of Jefferson County

/ Ted C. MacRae / 13 Comments

We stood a moment to contemplate the sublime and beautiful scene before us, which was such an assembly of rocks and water—of hill and valley—of verdant woods and naked peaks—of native fertility and barren magnificence… – Henry Rowe Schoolcraft, 1818-1819

In the Ozark Border south of St. Louis, a series of natural openings punctuate the dry, rocky forests of Jefferson County. Commonly called “glades” or “cedar glades,” these islands of prairie in a sea of forest are home to plants and animals more commonly associated with the Great Plains region further to the west. Extending in a narrow arc from central Jefferson County east and south into northern Ste. Genevieve County, these glades occur most commonly on south and southwest-facing slopes below forested ridges and are characterized by thin soils and exposed dolomite bedrock of Ordovician age. Glades are, in fact, a common natural feature throughout much of the Ozark Highlands, an extraordinary plateau where the great eastern deciduous forest begins to yield to the western grasslands. A much more extensive system of dolomite glades occurs in the White River Hills of southwest Missouri, where they often extend up steep slopes and over the tops of knobs to form what Schoolcraft called “naked peaks” and are now called “balds” (and spawning the “Baldknobbers” of Branson fame). Additional glade complexes occur throughout the Ozark Highlands on different rock substrates – igneous glades abound in the St. Francois Mountains, sandstone glades dot the Lamotte landscape in Ste. Genevieve County and the northern and western Ozarks, limestone glades can be found in the northern Ozarks near Danville and Lake of the Ozarks, and chert glades occur in extreme southwest Missouri. These different glade systems share a common feature – shallow soils where tree establishment is limited due to summer moisture stress. They differ vegetationally, however, due to differences in hydrology and soil chemistry as a result of their different substrates. Floristically, dolomite glades exhibit a high degree of diversity relative to other glade types.

The term “glade” is derived from the Old English “glad,” meaning a shining place – perhaps the early settlers found their open landscapes a welcome respite after emerging from the confining vastness of the eastern deciduous forest. Whatever the meaning, the glades of Jefferson County hold a special place in my heart, for I “grew up,” entomologically speaking, in those glades. As a young entomologist, fresh out of school, I spent many a day scrambling through the glades and surrounding woodlands. It was here where my interest in beetles, especially woodboring beetles, was born and later grew into a passion. For eight years I visited these glades often – attracted by the extraordinary diversity of insects living within the glades and congregating around its edges. My earliest buprestid and cerambycid papers contain numerous records from “Victoria Glades” and “Valley View Glades” – the two best-preserved examples of the glades that once occurred extensively throughout the area (more on this later). My visits to these glades ended in 1990 when I moved to California, and although I moved back to the St. Louis area in 1995, the focus of my beetle research has more often taken me to places outside of Missouri. It had, in fact, been some 10 years since my last visit to these glades until last week, when I was able to once again spend some time in them.

Ozark glades differ from the true cedar glades of the southeastern U.S. in that they are not a climax habitat – they depend upon periodic fires to prevent succession to forest. Some recent authors have suggested the term “xeric dolomite/limestone prairie” be used to distinguish the fire-dependent glades of the Ozarks from the edaphic climax cedar glades of the southeast (Baskin & Baskin 2000, Baskin et al. 2007). Fires have been largely suppressed throughout Missouri since European settlement, leading to encroachment upon the glades by eastern red-cedar (Juniperus virginiana). Pure stands of red-cedar have developed on many former glades, crowding out the herbaceous plants that depend upon full sun and leading to soil formation that supports further encroachment by additional woody plant species such as post oak (Quercus stellata), blackjack oak (Q. marilandica), flowering dogwood (Cornus florida), and fragrant sumac (Rhus aromatica) from the surrounding woodlands. Fire has returned to many of the Ozark glades situated on lands owned or managed by state and federal agencies such as the Missouri Department of Conservation, Missouri Department of Natural Resources, and U.S. Forest Service, as well as private conservation-minded organizations such as The Nature Conservancy. These agencies have begun adopting cedar removal and fire management techniques to bring back the pre-settlement look and diversity of the Ozark Glades. This is particularly true at Victoria Glades and Valley View Glades, the two largest and most pristine examples of the Jefferson County dolomite glade complex. Fires have been used to kill small red-cedars in the glades, as well as rejuvenate their herbaceous plant communities. Larger red-cedar trees are not killed outright by fire and must be removed by chainsaws. This above distant view of the TNC parcel at Victoria Glades shows many such burned red-cedars. The glades themselves are not the only habitat to benefit from this aggressive management – when I was doing my fieldwork here in the 1980’s the surrounding woodlands were a closed post oak forest bordered by fragrant sumac and with little or no understory in the interior. The photo at right now shows an open savanna with a rich understory of not only sumac and other shrubs, but also many herbaceous plants as well such as black-eyed susan (Rudbeckia hirta) and American feverfew (Parthenium integrifolium). Such open woodland more closely resembles what Schoolcraft saw across much of the Ozarks during his journey almost two centuries ago.

Victoria and Valley View Glades are dominated by little bluestem (Schizachyrium scoparium), Indian grass (Sorghastrum nutans), big bluestem (Andropogon gerardii) and prairie dropseed (Sporobolus heterolepis). A smaller but highly charismatic non-grass flora is also found on the glades – species such as Missouri evening primrose (Oenethera macrocarpa) (left), pale purple coneflower (Echinacea simulata) (pictured above and below), and prairie dock (Silphium terebinthinaceum) not only add beautiful color but also support both vertebrate and invertebrate wildlife. The Fremont’s leather flower (Clematis fremontii) is a true endemic, occurring only in this part of Missouri and entirely dependent upon these glades for its survival. Less well studied is the vast insect fauna associated with the glades. It is here where I first discovered the occurrence of Acmaeodera neglecta in Missouri. This small jewel beetle is similar to the broadly occurring A. tubulus but at the time was known only from Texas and surrounding states. In collecting what I thought were adults of A. tubulus on various flowers in the glades, I noticed that some of them were less shining, more strongly punctate, and exhibited elytral patterning that was often coalesced into longitudinal “C-shaped” markings rather than the scattered small spots typical of A. tubulus. These proved to be A. neglecta, which I have since found on many glade habitats throughout the Ozark Highlands. Both species can be seen in this photo feeding on a flower of hairy wild petunia (Ruellia humilis) – the lower individual is A. neglecta, while the upper individual and two inside the flower are A. tubulus. Another interesting insect-plant association I discovered at these glades was the strikingly beautiful Dicerca pugionata – another species of jewel beetle – and its host plant ninebark (Physocarpus opulifolius). Only a single Missouri occurrence had been reported for D. pugionata, despite the common occurrence of its host plant along rocky streams and rivers throughout the Ozark Highlands. This plant also grows at Victoria and Valley View Glades along the intermittent streams that drain the glades and in the moist toeslopes along the lower edges of the glades where water that has percolated through the rocks and down the slopes is forced to the surface by an impermeable layer of bedrock. Unlike the tall, robust, lush plants that can be found in more optimal streamside habitats with good moisture availability, the ninebark plants of Victoria and Valley View Glades are small and scraggly, usually with some dieback that results from suboptimal growing conditions. I surmise these plants have reduced capabilities for fending off attacks by insects, including D. pugionata, and as a result a healthy population of the insect thrives at these glades. Some might be inclined to call this beetle a pest, threatening the health of one of the glade’s plants. In reality, the insect finds refuge in these glades – unable to effectively colonize the vast reserves of healthy plants that grow along streams throughout the rest of the Ozarks, it strikes a tenuous balance with plants that are themselves on the edge of survival.

Despite the success in moving Victoria and Valley View Glades closer to their pre-settlement character, the integrity of these areas continues to be challenged. Poachers take anything of real or perceived value, and ATV enthusiasts view the open spaces as nothing more than tarmac. Pale purple coneflower occurs abundantly on these Jefferson County glades (but sparingly in other habitats – primarily rocky roadsides), where they provide a stunning floral display during June and sustain innumerable insect pollinators. Plants in the genus Echinacea also have perceived medicinal value, as herbalists believe their roots contain an effective blood purifier and antibiotic. There are no conclusive human clinical trials to date that fully substantiate this purported immune stimulating effect (McKeown 1999). Nevertheless, demand for herbal use has skyrocketed in recent decades, prompting widespread illegal harvesting of several coneflower species throughout their collective range across the Great Plains and Ozark Highlands. I witnessed massive removals of this plant from both Victoria and Valley View Glades during the 1980’s, but the pictures I took this year suggest that such illegal harvests have been suppressed and that the populations at both sites are recovering nicely.

The same cannot be said for the practice of rock flipping. This was a problem I witnessed back in the 1980’s, and I saw fresh evidence of its continued occurrence at both sites. The thin soils and sloping terrain leave successive layers of dolomite bedrock exposed, the edges of which shatter from repeated freeze-thaw cycles to create rows of loose, flat rocks along the bedrock strata. Lizards, snakes, tarantulas, and scorpions find refuge under these loose rocks, only to be ripped from their homes by flippers and transferred to a dark, cold terrarium to endure a slow, lingering death. As if poaching the glade’s fauna and watching them slowly die isn’t bad enough, the flippers add insult to injury by not even bothering to replace the rock in its original position after stealing its inhabitant, amounting to habitat destruction three times greater than the area of the rock itself. Firstly, the habitat under the rock is destroyed by sudden exposure of the diverse and formerly sheltered microfauna to deadly sunlight. Next, the habitat onto which the rock is flipped is also destroyed, as the plants growing there begin a slow, smothering death. Lastly, the upper surface of the rock, sometimes colonized by mosses and lichens that might have required decades or longer to grow, usually ends up against the ground – its white, sterile underside becoming the new upper surface. Rock flipper scars take years to heal, and nearly all of the flat, loose rocks seen in the more accessible areas of the glades exhibit scars of varying ages next to them. If a scar is fresh (first photo), I generally return to the rock to its original position – the former inhabitants cannot be brought back, but at least the original habitats are saved and can recover quickly. However, if a scar is too old (2nd photo) it is best to leave the rock in its new position – replacing it only prolongs the time required for recovery.

Even more damaging is ATV use. Herbaceous plants and thin soils are no match for the aggressive tread of ATV tires, and it doesn’t take too many passes over an area before the delicate plants are killed and loose soils ripped apart. I witnessed this become a big problem particularly on Victoria Glades during the 1980’s – actually finding myself once in a face-to-face confrontation with an ATV’er. Fortunately, he turned tail and ran, and it appears (for now) that such abuses have stopped, as I saw no evidence of more recent tracks during this visit. But the scars of those tracks laid down more than two decades ago still remain painfully visible. I expect several more decades will pass before they are healed completely.

My return to Victoria and Valley View Glades was a homecoming of sorts, and I was genuinely pleased to see the progress that has been made in managing these areas while revisiting the sites where my love affair with beetles was first kindled. Sadly, however, the larger glade complex of Jefferson County continues to deteriorate. Restoration acreage aside, red-cedar encroachment continues unabated on many of the remaining glade parcels – large and small – that dot the south and southwest facing slopes in this area. It has been conservatively estimated that as much as 70% of the original high quality glades in Missouri are now covered in red-cedar. Many of these are privately held – their owners either do not recognize their ecological significance or are loathe to set fire to them. An example can be seen in the picture here – this small parcel is part of the Victoria Glades complex but lies on private land in red-cedar choked contrast to the Nature Conservancy parcel immediately to the south. Small numbers of herbaceous plants persist here, but without intervention by fire or chainsaw their numbers will continue to dwindle and the glade will die. Aside from the loss of these glades, the continuing reduction of glade habitat complicates management options for preserved glades as well. Many glade associated invertebrates are “fire-sensitive” – i.e., they overwinter in the duff and leaf litter above the soil and are thus vulnerable to spring or fall fires. While these fires are profoundly useful for invigorating the herbaceous flora, they can lead to local extirpation of fire-sensitive invertebrate species within the burn area. Recolonization normally occurs quickly from unburned glades in proximity to the burned areas but can be hampered if source habitat exists as small, highly-fragmented remnants separated by extensive tracts of hostile environment. Grazing also continues to threaten existing remnants in the Jefferson County complex. Grazing rates are higher now than ever before, with greater negative impact due to the use of fencing that prevents grazers from moving to “greener pastures”. Over-grazing eliminates native vegetation through constant depletion of nutrient reserves and disturbance of the delicate soil structure, leading to invasion and establishment of undesirable plant species. Eventually, the glade becomes unproductive for pasture and is abandoned – coupled with fire suppression this leads to rapid woody encroachment. It is truly depressing to drive through Jefferson County and recognize these cedar-choked glades for what they were, able to do nothing but watch in dismay as yet another aspect of Missouri’s natural heritage gradually disappears. The continued loss of these remnant glades makes careful use of fire management on Victoria and Valley View Glades all the more critical – ensuring that a patchwork of unburned, lightly burned, and more heavily burned areas exists at a given time will be critical for preventing invertebrate extirpations within these managed areas.

I close by sharing with you a few more of the many photographs I took during this visit – stiff tickseed (Coreopsis palmata), three-toed box turtle (Terrapene carolina triunguis), climbing milkweed (Matelea decipiens – see the excellent post about this plant on Ozark Highlands of Missouri), downy phlox (Phlox pilosa), green milkweed (Asclepias viridiflora), and a “deerly” departed native browser.

Ozark Trail – Marble Creek Section

/ Ted C. MacRae / 7 Comments

If you know wilderness in the way that you know love, you would be unwilling to let it go…. This is the story of our past and it will be the story of our future. – Terry Tempest Williams


During the past several years that Rich and I have been hiking the Ozark Trail, most of our hikes have taken place in the fall and winter months. From a hiker’s perspective, I really enjoy these off-season hikes – the foliage-free canopy affords unobstructed views of the terrain and vistas, the cool (even cold) temperatures are more comfortable under exertion (provided one has properly layered), and there are no mosquitos to swat, ticks to pick, or gnats to incessantly annoy. I also enjoy them as a naturalist, for the world is quiet and still, allowing me to focus on things I may not notice amidst the cacophany of life during the warmer months. By the end of winter, however, the biologist in me yearns to once again see bugs and flowers and the great interplay of life. Unfortunately, this makes something as simple as hiking from point A to point B rather difficult – too many distractions! Nevertheless, each spring Rich and I try to hike a small leg of the Ozark Trail before the crush of summer activities fills our calenders. Last week, we chose the Marble Creek Section, an orphan stretch (for the time being) in the rugged St. Francois Mountains that eventually will connect to the famed Taum Sauk Section. It would be our first return visit to the St. Francois Mountains since we first embarked on our goal to hike the entirety of the Ozark Trail.

The St. Francois Mountains are the geologic heart of the Ozark Highlands. Since their primordial birth 1.5 billion years ago, recurring cycles of erosion and deposition have worn them down and covered them up, only to see them reemerge once again as the younger rocks covering them were themselves stripped away. The Ozarks are an ancient landscape with ancient hills, and none are older than those of the St. Francois Mountains. It’s as if the Earth itself began in these mountains. We began our hike at Crane Lake, a clear, blue 100-acre lake built in the 1970s by the Youth Conservation Corps. The trail surrounding the lake was built in 1975 and is, in its own right, a National Recreation Trail. It meanders along the lakeshore and through hillside igneous glades and descends into a deep ravine below the dam where Crane Pond Creek cascades through spectacular rhyolite shut-ins. East of the lake the trail connects to the Ozark Trail proper and continues to Marble Creek campground. All told, we would be hiking a 9-mile stretch.

I knew we were in a special place almost from the beginning when I noticed a small flowering plant growing next to the trail under the mixed pine/oak canopy. I’m not a very good botanist, but I instantly recognized the plant as dwarf spiderwort (Tradescantia longipes), an Ozark endemic known from only a handful of counties in Missouri and Arkansas. I knew this only because I had just the night before read about this wonderful plant on Ozark Highlands of Missouri, a superb natural history blog focused on my beloved Ozarks. Reading about this lovely, diminutive member of the genus, I wondered if I might encounter it on my own hike the next day. As we searched off the trail and near the lakeshore we encountered dozens of the plants, each with one or two exquisite blue flowers. Our excitement at seeing a true Ozark endemic increased with each plant we encountered, giving us confidence that its future, at least in this area, appears secure. Of the numerous photographs I took, I share two that show its short, squat habit and filament-covered stamens. Eventually we decided we needed to move on – we had spent 20 minutes and only hiked 100 ft!

Looping around the south side of the lake, the trail traversed mesic to dry-mesic upland forest and afforded spectacular views of the lake and rugged north shore. The spring ephemerals had already come and gone, replaced by such classic woodland denizens as birdfoot violet (Viola pedata, pictured), fire pink (Silene virginica), cream wild indigo (Baptisia leucophaea), four-leaved milkweed (Asclepias quadrifolia), Pursh’s phacelia (Phacelia purshii), and shooting star (Dodecatheon meadia). Insect life was abundant, however, the only species seen in one of my chosen specialties, metallic wood boring beetles (family Buprestidae), were early spring species of Acmaeodera – pictured here is A. ornata on a dewberry (Rubus sp.) flower. This pretty little beetle occurs throughout eastern North America in early spring on a variety of flowers, where adults feed on pollen and mate. Eggs are laid on dead branches of certain hardwood trees, through which the larvae tunnel as they develop. Dry, dead wood contains little nutritional value, and the larvae cannot digest the cellulose. As a result, they eat considerable volumes of wood, extracting whatever nutrients they can for growth and ejecting the bulk as sawdust, which they pack tightly in their tunnels behind them. A year or more might be required before they have grown sufficiently to transform into the adult and emerge from the wood. A smaller relative, Acmaeodera tubulus, was also seen on flowers of native dwarf dandelion (Krigia biflora).

We stopped for lunch on a little point extending out towards the lake. The forest overstory was dominated by an open mixture of white oak (Quercus alba) and shortleaf pine (Pinus echinata). Thickets of highbush huckleberry (Vaccinium stramineum) and carpets of reindeer moss in the open areas belied the acidic nature of the igneous substrate. Stands of bastard toad flax (Comandra richardsiana) in full bloom were found at the tip’s dry, rocky tip. These interesting plants feed parasitically on neighboring plants, attaching to the roots of their hosts by means of their long, thin rhizomes. Resuming our hike, we descended down into a shaded, moist draw feeding the lake and saw a huge royal fern (Osmunda regalis var. spectabilis) bush. I had never seen this aptly named fern before, but it was immediately recognizeable by its large size (~5 ft in height) and presence of distinctive, fertile leaflets on some of its upper branches – a very striking and handsome fern, indeed. Nearby was a smaller, but no less attractive species of fern that I take to be marginal sheild fern (Dryopteris marginalis) – another species I have not seen before (or at least made the effort to notice).

Soon, we reached the dam and for the first time saw the spectacular rhyolite shut-ins. While perhaps not quite as impressive as the nearby and much more famous Johnson’s Shut-Ins, Rich and I nonetheless watched entranced as the water roared over the smooth igneous rock exposure, forming elegant cascades, rushing through narrow chutes, and swirling into small pools. Steep canyon walls rose sharply on each side of the shut-ins, as if standing guard. Clambering amidst the pines and cedars that cloaked them, we found this maidenhair spleenwort (Asplenium trichomanes) nestled within a crack on a vertical rock face under continuous deep shade. Reaching the top of the bluffs, we were greated by one of my favorite of all Ozark habitats – the igneous glade. Glades are natural island communities surrounded by a sea of forest. Their shallow, dry, rocky soil conditions support plants and animals more adapted to prairie or desert habitats. Specific communities are influenced by the type of rock below – igneous and sandstone substrates support lichens, mosses, and other acid soil-loving plants, while limestone and dolomite substrates support a more calcareous flora. The photo here shows the massive boulder outcroppings typical of igneous glades and their weather-resistant bedrock. We hoped to see a collared lizard (Crotaphytus collaris), perhaps Missouri’s finest saurian reptile, but today was not the day. We did, however, see adults of the beautiful and aptly named splendid tiger beetle (Cicindela splendida) sunning themselves on the bare rock surfaces – flashing brilliant green and clay-red. The adults we saw had spent the winter deep inside tunnels dug into the rocky soil the previous fall and were now looking for mates. Male tiger beetles grab females by the neck, their jagged, toothy jaws fitting precisely in grooves on the female neck designed specifically for such. As I looked upon this prairie island within the forest, I thought about how the St. Francois Mountains were once themselves islands. I realized the landscape we were exploring today was itself a fossil – with rhyolitic ‘islands’ amidst a ‘sea’ of cherty dolomite laid down a half billion years ago in the warm, tropical, Cambrian waters that surrounded the St. Francois Islands, by then already a billion years old themselves. Yes, the Earth itself seems to have begun here.

Leaving the glade and once again entering the acid pine forest, we came upon one of the most striking floral displays that either of us have ever witnessed – wild azalea (Rhododendron prinophyllum) in the midst of full bloom! I have known about several colonies of this plant for many years now but had only seen them at the very end of the bloom period, with just a few, pitiful, limply hanging flowers still attached. Today, the plants were absolutely dazzling. The blossoms were not only visually attractive, a deep pink color, but also unexpectedly fragrant. We stood amongst several specimen plants as tall as ourselves, taking picture after picture amidst the clovelike aroma wafting around us.

We checked our watches – we were now 3 hours into our hike and had traversed just 2 miles. Clearly, this was not a sustainable pace, so we put our heads down and focused on covering ground. Once leaving the vicinity of Crane Lake, the trail became rather difficult to follow – it obviously receives little use, and in one stretch some logging activities had obliterated the trail completely. Were it not for the sporadic pieces of orange flagging tape tied just within sight of the previous, we would not have know where to go. At one point, we got completely off-track and had to backtrack a full half mile before we found the proper trail. The day put our contour map reading skills to their greatest test yet. It was difficult and strenuous terrain, with steep up and down grades and few long ridgetop stretches until (thankfully) the final 2 miles, which terminated in a long descent (more thankfully) to Marble Creek Campground. Despite the difficulties in following the trail and our not bringing enough water, I would have to rank this section a close second to the Taum Sauk stretch for its ruggedness, spectacular vistas, and unique plant communities. Yes, the St. Francois Mountains are truly the heart of the Ozarks.

Pickle Springs Natural Area

/ Ted C. MacRae / 3 Comments

Pickle Springs Natural Area lies in Ste. Genevieve County, about an hour south of St. Louis. Like Hawn State Park, the geology of this area and its effect on the flora have resulted in a unique collection of geologic features and plants found in few other places. The Lamotte sandstone outcrops that dot the landscape were formed nearly half a billion years ago when sand deposited in an extensive maze of braided river channels was cemented and buried under younger layers of limestone and dolomite formed from deposits on the floors of ancient seas that covered the interior of the continent. Later, the periods of uplift that created the St. Francois Mountains and resulting erosion of overlying strata once again exposed the sandstones at the surface. Millions of years of water, ice, rain, wind, and plants have further shaped the exposed sandstones, creating fanstastic shapes and formations and cool, deep canyons. The weathered sandstone created acid soils which support many unique plants. During the ice ages, northern plants and animals moved into the area ahead of the advancing glaciers. Mammoths roamed the landscape grazing on the northern vegetation supported by the area’s acid soils. Eventually the ice retreated, and so did the mammoths. But many of the plants remained – able to hang on in the cool, moist canyons long after the mammoths that once roamed these canyons disappeared. Because of this unique concentration of rare plants and geologic features, the area has been designated a Missouri Natural Area and a National Natural Landmark.

Yesterday I hiked the aptly-named ‘Trail Through Time’ with my family. This 2-mile trail is one of the most “feature-packed” trails in the state, with something to look at around almost every bend. Almost immediately the trail leads to the Slot, the result of a vertical fracture in the Lamotte sandstone that was loosened by leaching and then widened by erosion. The unique partridge berry (Mitchella repens) was seen on the moist, vertical walls of the rock, growing among strange holes, pockets, and ridges that formed as a result of the sand grains being variably cemented.


A short distance from The Slot lie Cauliflower Rocks – large moundlike formations (also called hoodoos or rock pillars) formed from jointed or fractured sandstone that undergoes deep solutional weathering followed by erosion and weather-mediated shaping. Hoodoos occur primarily in this type of rock due to its granular, variably cemented and cross-bedded matrix.


On the south side of Cauliflower Rocks lies a special type of buttress arch called Double Arch. It occurs at almost a right angle to the adjacent rock outrcrops, suggesting formation along a set of fractures running perpendicular to the main fracture trend of the area, but the precise details of its formation remain a mystery.


After leaving Cauliflower Rocks the trail descends steeply into a deep valley, at the bottom of which lies Pickle Creek just below its origin in a box canyon south of the Natural Area. Lush vegetation in this cool, moist valley contrasts with the stark rocks seen earlier.


The creek is fed by a series of seeps, allowing the valley to remain moist even during the dry summer months, and along with the acid soils support a unique plant community. Lush colonies of ferns (I believe this is Polypodium virginianum L.) covered the rocks adjacent to the creek…


…while this rattlesnake plantain orchid (Goodyera pubescens) was seen in a colony growing at the base of a black oak tree (Quercus velutina) just above the creek.


Mosses and lichens were also abundant in the valley. This little hair cap moss (Polytrichum sp.) with its distinctive fruiting structures was growing in a colony at the base of another black oak tree. The members of this genus prefer acidic environments.


Further ahead, along Bone Creek, several colonies of wooly aphids (family Aphididae) were seen on the branches of a small hop hornbeam tree (Ostrya virginiana).


The highlight of the hike had to be in Spirit Canyon at Owl’s Den Bluff. The horizontal layers of sandstone, each deposited on the steep downstream slopes of sandbars, are clearly visible in the towering bluff face. At the bottom lie bluff shelters – formed where lower sandstone layers collapse due to weathering or leaching, and where native Americans almost surely camped out. The sun never reaches parts of these shelters, providing ideal conditions for a variety of mosses and liverworts – many of which are known only from this area. Fallen boulders and collapsed portions of the bluff face provided photo opps for the daring…


…and good exploring for the nimble.


By now, the trail has passed the halfway point and is looping back to the west, where it ascends to Dome Rock Overlook. Along the way, a fascinating variety of lichens, including reindeer lichen, covers the forest floor where they are supported by the acid soils.


Dome Rock Overlook is a the largest hoodoo complex in the Natural Area. The thin soils and exposed conditions create a harsh, dry, windswept environment that only the hardiest of plants can withstand. Only a few small blackjack oaks (Quercus marilandica), shortleaf pines (Pinus echinata), and farkleberry (Vaccinium arboreum) survive here. Despite their small size, some of the trees growing here are at least 150 years old.


The trail descends from Dome Rock Overlook and passes underneath, providing spectacular views of the sheer rock face below the overlook. The trail completes its descent back into Pickle Creek Valley, where Pickle Spring can be seen. This small, permanent spring – an unusual feature in sandstone where seeps are more common – was an important source of water for early settlers.


Further along the trail lies one of the areas most unusual features – Rockpile Canyon – formed some 50 years ago (a fraction of a second in geologic time) when part of a sandstone bluff collapsed in a rumble, leaving behind a sheer bluff face and a jumbled pile of large boulders. A short spur in the trail leads to the head of a small box canyon, where some of the 20+ ice age relict plant species can be seen growing in the acid soils and cool, moist canyon walls.

Near the end of the loop lies Piney Glade, an area where the exposed sandstone bedrock once again creates a dry, harsh environment. Poverty grass and little bluestem grow in small, shallow pockets of soil scattered amongst stunted shortleaf pines and blackjack oaks – creating a small prairie surrounded by a sea of forest. All three forms of lichens can be found on the rocks and soils of the glade – the aptly named crustose lichens cling tightly to rock surfaces amongst foliose (leafy) and fruticose (branched) lichens.