“Dungers and Chafers – a Trip to South Africa”

Those of you who enjoy field trip accounts should check out the December 2008 issue of SCARABS. The lead article – authored by your’s truly – is a scarabcentric travelogue of an insect collecting trip I took to South Africa several years ago. Scarabs?!, you say? Well, even though I focus on bups, ‘bycids, and tigers (some would argue that actually demonstrates lack of focus), I never pass on the opportunity to collect “cool” insects of all types when traveling somewhere as “exotic” as Africa – and scarabs are definitely cool! Still, I did manage to sneak past the editors a few words and pictures about buprestids, one of the more impressive of which I offer here as further enticement. You can also read about heart attacks, flying Tonka trucks, and evil minions.

Photos: (above) me standing next to a termite mound near the Waterberg, Northern Province (photo by Chuck Bellamy); (left) Evides pubiventris (family Buprestidae, tribe Evidiini) suns itself on high terminal foliage of Lannea discolor (family Anacardiaceae), Waterberg, Northern Province.

Two new species of Agrilus from Mexico

ResearchBlogging.orgThe enormous, cosmopolitan genus Agrilus (family Buprestidae – commonly called jewel beetles or metallic woodboring beetles) contains nearly 4,000 described species (Bellamy 2008). With many more still awaiting description, it is perhaps the largest genus in the entire animal kingdom (Bellamy 2003). Agrilus species are primarily twig and branch borers, utilizing recently dead wood for larval development – although there are notable exceptions, e.g. Agrilus anxius (bronze birch borer), A. bilineatus (twolined chestnut borer), and A. planipennis (emerald ash borer), which attack the trunks of living trees and, thus, are of significant economic importance in forest and ornamental landscapes. Host specificity among Agrilus species ranges from highly monophagous – associated exclusively with a single plant species – to rather oliphagous – utilizing several, usually related, plant genera. Adults of Agrilus species are most often found on the foliage of their larval hosts and do not generally visit flowers, as is common in some other genera (e.g., Acmaeodera and Anthaxia). Interestingly, despite the diversity and worldwide distribution of the genus, no species of Agrilus are known to be associated with coniferous plants – a fact that has limited their expansion into the vast northern boreal forests.

Texas, Bexar Co., San Antonio, nr. Fort Sam Houston, em. 25.iv-14.v.1997 ex Phoradendron tomentosum coll. ii.1997, D. Heffern & D. W. SundbergAs can be imagined by its enormity, a comprehensive understanding of the genus will remain a distant goal for many years. Progress will come incrementally, as formal descriptions of new species gradually improve our knowledge of the fauna that exists in each of the world’s main biogeographic provinces. In a recent issue of the online journal Zootaxa, Dr. Henry Hespenheide (UCLA) describes two new species of Agrilus from Mexico. These two species are interesting because of their association with ‘mistletoe’ plants in the genus Phoradendron (family Viscaceae1), obligate hemiparasites that attach to branches and stems of various woody trees and shrubs in tropical and warm temperate regions of the New World. Plants in this genus are known to support a variety of host-restricted insect herbivores, principally in the orders Hemiptera, Coleoptera and Lepidoptera. A single buprestid species has been associated with Phoradendron to this point – Agrilus turnbowi, recently described from specimens reared from dead stems of Phoradendron tomentosum attached to mesquite (Prosopis glandulosa) in southern Texas (Nelson 1990) and pictured here from a specimen in my collection that was reared from dead mistletoe collected at the type locality. At the time of its description, this species was not relatable to any of the other known species in the genus.

1 The Angiosperm Phylogeny Group (2003) includes the Viscaceae in a broader circumscription of the family Santalaceae. However, recent molecular studies suggest the Santalaceae are polyphyletic, with strong support for Viscaceae as a distinct, monophyletic clade (Der & Nickrent 2008).

The two new Mexican species – A. andersoni from Guerrero and Puebla (Figs. 1-3), and A. howdenorum from Oaxaca (Figs. 4-6) – are apparently related to A. turnbowi, which they resemble by their purplish-red coloration and complex pattern of golden setae on the elytra. They are also superficially very similar to each other but differ most notably in size and the overall color and pattern of setae on the elytra.

Figures 1–3. Agrilus andersoni Hespenheide: 1. dorsal habitus; 2. lateral habitus (scale bar indicates 2.0 mm); 3. genitalia of male (scale bar indicates 0.5 mm) (from Hespenheide 2008).

Figures 4–6. Agrilus howdenorum Hespenheide: 4. dorsal habitus; 5. lateral habitus (scale bar indicates 2.0 mm); 6. genitalia of male (scale bar indicates 0.5 mm) (from Hespenheide 2008).

Hespenheide speculates that the color and pattern of the golden setae on the elytra may serve to make the beetles less conspicuous by disruptive coloration, noting the similar coloration of the setae to the leaves of Phoradendron as seen in the photograph of Agrilus howdenorum on its host plant (Fig. 7). This form of crypsis may also be enhanced by the purplish-red ground coloration of the adult, which resembles that of the small, darkened blemishes often observed on the foliage of these plants.

Figure 7. Agrilus howdenorum adult on mistletoe host plant near Diaz Ordaz, Oaxaca, México. The golden setae on the elytra are similar in color to the leaves of the mistletoe and may function as a disruptive color pattern. Photograph by C.L. Bellamy (from Hespenheide 2008).

REFERENCES

Angiosperm Phylogeny Group. 2003. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society, 141: 399-436.

Bellamy, C. L. 2003. The stunning world of jewel beetles. Wings, Essays on Invertebrate Conservation, 26(2): 13-17.

Bellamy, C. L. 2008. A World Catalogue and Bibliography of the Jewel Beetles (Coleoptera: Buprestoidea), Volume 4: Agrilinae: Agrilina through Trachyini. Pensoft Series Faunistica No. 79, 722 pp.

Der, J. P. & D. L. Nickrent. 2008. A Molecular Phylogeny of Santalaceae (Santalales). Systematic Botany, 33(1):107-116.

Hespenheide, H. A. (2008). New Agrilus Curtis species from mistletoe in México (Coleoptera: Buprestidae) Zootaxa, 1879, 52-56

Nelson, G. H. 1990. A new species of Agrilus reared from mistletoe in Texas (Coleoptera: Buprestidae). The Coleopterists Bulletin, 44(3):374-376.

A new species of Xenorhipus from Baja California

ResearchBlogging.orgA few months ago I discussed Trichinorhipis knulli of the tribe Xenorhipidini (family Buprestidae). Members of this tribe exhibit highly sexually dimorphic antennae, with the distal segments of the male antennae highly modified into a very extended flabellate or lamellate condition. The surfaces of the flabellae/lamellae are covered with numerous, presumably olfactory sensillae that are lacking on female antennae (which retain the unmodified serrate condition), strongly suggesting a function involving detection of female sex pheromones. Although chemosensory structures are present on the antennae of nearly all buprestids, the extreme modification exhibited by the males of species in this tribe is not a common occurrence. Nevertheless, similar modifications have evolved independently in a few other genera within the family, including Knowltonia (four species in western North America), Mendizabalia and Australorhipis (monotypic genera in South America and Australia, respectively), and two species of the enormous Australian genus Castiarina. Indeed, males of Knowltonia and the two Castiarina species possess what might be termed ‘bipectinate’ or ‘biflabellate’ antennae due to dual projections from the terminal antennomeres (see Bellamy & Nylander 2007 for a more complete discussion of male antennal modifications in Buprestidae). The tribe Xenorhipidini is the most diverse group in which these modifications have arisen, comprised of the monotypic Trichinorhipis from California and the closely related Hesperorhipis (four species in Arizona and California) and Xenorhipis (until now, 14 species from North and South America and the West Indies).

Xenorhipis bajacalifornica Westcott, 2008 – holotype ♂ (1) & allotype ♀ (2).
Photos by Steve Valley (Oregon Department of Agriculture).

In a recent issue of the online journal Zootaxa, Rick Westcott (Oregon Department of Agriculture) describes a new species of Xenorhipis from the Cape Region of Baja California Sur, Mexico. Although assigned to the genus Xenorhipis, the new species – X. bajacalifornica – seems to bridge the gap between the genera Xenorhipis and Hesperorhipis. As currently recognized, Xenorhipis is distinguished from Hesperorhipis by the shape of the posterior coxal plates, which are scarcely narrowed laterally in the former genus, while in the latter genus they are triangular and with the hind margin strongly oblique. In X. bajacalifornica the posterior coxal plates are somewhat triangular but not as acute laterally as in some species of Hesperorhipis. Xenorhipis bajacalifornica also differs from other described Xenorhipis in its strongly abbreviated elytra, which in males barely reach the second ventrite – similar to species of Hesperorhipis. Other described Xenorhipis exhibit less abbreviated elytra, which cover at least the first three ventrites and in some species almost the entire abdomen. Despite these similarities to Hesperorhipis, a consistent distinguishing character between the two genera was found in the male antenna – in Xenorhipis the flabellar processes begin with the second antennomere, while in Hesperorhipis they begin with the third. It was on this basis that the new species was assigned to the genus Xenorhipis. (The genus Trichinorhipis differs from both Xenorhipis and Hesperorhipis by its rounded rather than quadrate pronotum and its unabbreviated elytra that cover the entire abdomen and has, as a result, been placed in its own subtribe.)

Xenorhipis brendeli ♂Xenorhipis brendeli ♀The photos left show the male (L) and female (R) of Xenorhipis brendeli, the only species in the tribe occurring in eastern North America (west to Minnesota and eastern Texas). Adults of this species are not commonly encountered and have been collected on a variety of deciduous hardwoods but reared almost exclusively from species of hickory (genus Carya). These individuals were reared from dead branches collected in southeastern Missouri – the male from pecan (Carya illinoensis) and the female from shellbark hickory (Carya laciniosa). The male exhibits the scarcely abbreviated elytra that cover almost the entire abdomen (as discussed above). Stan Wellso reported large numbers of males attracted to caged live females in Texas, apparently responding to sex pheromones released by the females.

Xenorhipis osborni ♀Xenorhipis osborni ♂This is another species in the genus – Xenorhipis osborni – known from west Texas. Joseph Knull described the species in 1936 from specimens collected in the Davis Mountains on whitethorn acacia (Acacia constricta), but larval hosts remained unknown until I reared a series of these specimens from dead branches of black acacia (Acacia rigidula) collected above the Pecos River in Val Verde County. I’ve also reared a few specimens from dead branches of catclaw acacia (Acacia greggii) collected in Big Bend National Park, and I wouldn’t be surprised if it breeds in other species of acacia. Again, in this speices the elytra are only slightly abbreviated, though more so than in Xenorhipis brendeli above and also more so in the male (L) than in the female (R). The male of this species is one of the prettiest I’ve encountered in the tribe.

Hesperorhipis albofasciatus ♂Hesperorhipis albofasciatus ♀The genus Hesperorhipis is illustrated here by these photos of H. albofasciatus. These specimens were reared by Rick Westcott from dead branches of walnut (Juglans sp.) – its only known host – collected in Tulare County, California. The elytra in this species are much more abbreviated than in Xenorhipis brendeli and X. osborni but similar to those of X. bajacalifornica – again with the male (L) exhiting greater abbreviation than the female (R). The three remaining species of Hesperorhipis exhibit even more highly abbreviated elytra than H. albofasciatus.

Dr. Charles Bellamy (California Department of Food and Agriculture) is currently revising the tribe. It will be interesting to see how, ulimately, he treats Xenorhipis and Hesperorhipis, given the blended characters exhibited by some species.

REFERENCE

Westcott, R. L. (2008). A new species of Xenorhipis LeConte and of Mastogenius Solier from Mexico, with a discussion of Chrysobothris ichthyomorpha Thomson and its allies and notes on other Mexican and Central American Buprestidae (Coleoptera) Zootaxa, 1929, 47-68

Trichinorhipis knulli

Just a little diddy on one of the more interesting species I’ve encountered over the years while I finish up a longer piece on the Loess Hills of Missouri. The specimen shown here is a male Trichinorhipis knulli. This quirky little species belongs to the equally quirky little tribe Xenorhipidini (family Buprestidae). Members of this tribe are among the few groups of Buprestidae in which evolution of the male antenna has diverged dramatically from the typical condition (i.e., serrate). In the Xenorhipidini, this condition may be considered very extended flabellate or even lamellate. As I mentioned, only males exhibit this antennal modification – females possess typical serrate antennae. The functional significance of this almost certainly involves detection of female sex pheromones. The surfaces of the flabellae in these species are covered with numerous presumably olfactory sensillae that are lacking on female antennae, and males of a related species (Xenorhipis brendeli) have been observed attracted in large numbers to caged live females. This antennal condition appears to have arisen independently in three other groups of Buprestidae as well, but Xenorhipidini is the only non-monotypic tribe in which males of all member species possess the condition.

Trichinorhipis knulli is restricted to southern California and has been encountered most often in the vicinity of Mountain Springs in Imperial County (just north of the Mexican border), where it breeds in dead branches of jojoba, Simmondsia chinensis. Very few individuals have actually been observed in the field – most existing specimens have been reared from caged, infested branches (as is the case with this specimen, which emerged August 1994 from a dead branch I collected in October 1992 – patience prevails!). At only 3.6 mm in length, it is one of the smallest members of the family, but I think you’ll agree that it is just as impressive under the microscope as any of the larger members of the family. The genus is monotypic (although I hear rumor of an undescribed species from west Texas) and has been placed in its own subtribe (Trichinorphidina) within the Xenorhipidini due to unique characters that distinguish it from the other included genera (Hesperorhipis and Xenorhipis). These include its entire (not abbreviated) elytra and broadly rounded pronotum lacking lateral margins. In Hesperorhipis and Xenorhipis the elytra are abbreviated, and the pronotum is quadrate with distinct lateral margins. The organization of the antennal sensillae also differs between Trichinorhipis and these other genera.

The tribe Xenorhipidini is currently being revised by my colleague and friend, Dr. Charles Bellamy, California Department of Food and Agriculture, Sacramento.

Dicerca pugionata

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

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.

The Chrysobothris femorata “problem”

I found a young cottonwood tree (Populus deltoides) the other day that had recently fallen over in one of the many storms we’ve had this spring. Anytime I see one of these “windthrows” I immediately think – woodboring beetles! Windthrows are attractive to numerous species of Buprestidae and Cerambycidae, and when I find one I try to revisit it often as the season progresses and different beetle species – active at different times and attracted to wood at different stages of dying or death – are encountered. This particular tree was only partially uprooted and so still had fresh foliage in the crown. While death is inevitable, it will be a slow, lingering death as the remaining soil-bound roots try in vain to sustain the fallen tree. This is an ideal situation for attracting species of the genus Chrysobothris, which seem to respond to plant volatiles emitted from trees under duress or recently killed. In the deciduous forests of eastern North America, C. femorata and related species are the most commonly encountered Chrysobothris attracted to these situations. Nursery growers and landscapers know this insect as the “flatheaded apple tree borer” – in reference to the appearance of the larvae as they tunnel under the bark of one of its favored hosts. The species has in fact, however, been recorded breeding in some two dozen genera of deciduous woody plants throughout the continental states and Canada, an unusual level of polyphagy for a genus of beetles in which most species typically exhibit a fair degree of host fidelity.

The problem is, “C. femorata” is not really a species, but a complex of closely related species. Entomologists have recognized this for some time, and while diagnostic characters have been identified for some of the more distinctive members of the group, such characters have remained elusive for C. femorata and its closest relatives. As a result, the species has become sort of a “trash can” for specimens that could be not be assigned to one of these more distinctive species, and in many museum collections large series of specimens can be found labeled simply “C. femorata species complex”. Fortunately, some much needed clarity was provided earlier this year by Stanley Wellso and Gary Manley, who after years of careful, systematic study at last published a revision of the Chrysobothris femorata species complex. In their work, six new species were described and one species resurrected from synonymy under C. femorata. Three of the new species occur in the western U.S., another is restricted to Georgia and Florida, and the remaining two new species and one resurrected species occur broadly across the eastern or southeastern U.S. This brings to 12 the total number of femorata-complex species in North America, with nine occurring in the eastern U.S. and seven in Missouri. The characters used to distinguish the species are subtle but consistent, and available biological data seem to support the species as now defined.

Of the dozen or so Chrysobothris individuals I collected on the fallen cottonwood during this past week, all but one represent C. femorata (as now defined). The photos I share here show some of the characters that distinguish this species from its closest relatives – primarily the straight rather than curved lateral margin on the last third of the elytra and the generally distinctly reddish elytral apices (most easily seen in the full-sized versions of the photos – click to view). Females (first and second photos) tend to show distinct reddish tinges behind the eyes and on top of the head as well. Males (third photo) can be distinguished from females by their bright green face (I tried valiantly but could not get one of these guys to pose in a position showing such). The photos also illustrate some of the typical behaviors displayed by these beetles, with males rapidly searching up and down the trunk looking for mates (third photo), and females probing cracks and crevices in the bark with their ovipositor looking for suitable sites to deposit their eggs (second photo). Of the two dozen host genera recorded for this species, many likely refer to some of the newly described species. In particular, records of this species from oak (Quercus spp.) and hackberry (Celtis spp.) may refer to the new species C. shawnee and C. caddo, respectively. As now defined, this species is still quite polyphagous and occurs throughout the continental U.S., but it is more common east of the continental divide and appears to prefer maple (Acer spp.), birch (Betula spp.), sycamore (Platanus occidentalis), poplar (Populus spp.), and especially rosaceous hosts such as hawthorn (Crataegus spp.), apple (Pyrus malus), pear (Pyrus communis), and cherry (Prunus spp.). Also, of all the species in this complex, C. femorata appears to be the most partial to stressed or dying trees (as with these individuals collected on live, windthrown cottonwood) rather than completely dead hosts. Wellso and Manley note that considerable variation still exists among individuals assignable to their more restricted definition of C. femorata. Thus, it is possible that more than one species is still involved, particularly among those utilizing hardwood hosts (e.g. apple, maple, etc.) versus softwoods (e.g., poplar, birch, etc.). Detailed biological studies will likely be required to identify any additional species that might be hiding amongst these populations.

Ozark Trail – Marble Creek Section

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.