Revisiting the Swift Tiger Beetle – Part 2

…continued from Revisiting the Swift Tiger Beetle – Part 1.

The rain that cut short my visit to Alabaster Caverns in northwestern Oklahoma followed me as I drove east towards Tallgrass Prairie Preserve in northeastern Oklahoma. I had called Mike when I began my drive to tell him the great news – I had located Cylindera celeripes at Alabaster Caverns, and the population appeared to be quite robust. This was great news for the species, which seems to have disappeared from many parts of its range and is holding out primarily in the Flint Hills of Kansas. Mike and Jane had just arrived at Tallgrass Prairie when I called, and I told them to expect me to show up in about three hours. Tallgrass Prairie preserve is the largest intact tallgrass prairie remnant in the world, but my interest in it was due to the fact that ecologically it lies within the southern realm of the Flint Hills. I thought there might be a chance of finding C. celeripes in the preserve, extending its currently known distribution further south into northeastern Oklahoma as well. As I continued the drive, however, the rain came down harder and harder, and after I had driven about halfway to the preserve, I got a call from Mike. It had started raining there as well, and the weather forecast was calling for rain through tomorrow and possibly into Friday. They had decided to call it quits and start heading back towards St. Louis.

Me? I wasn’t nearly ready to punt on the trip. However, I hadn’t made any contingency plans and, thus, didn’t have a clue what to do next. I decided to drive into the next town and look for a coffee house where I might get a wi-fi connection, study the weather forecasts for surrounding areas, and then decide what to do next. There were several possibilities – I could drive north up into Kansas to look for the Flint Hills population of C. celeripes, but that area still seemed in the path of the frontal disturbances that would be ripping through Oklahoma and Texas for the next day or two. Or, I could continue on into southern Missouri and do some blacklighting in the Ozarks, but that just seemed like spending time without a real purpose, and eventually the rain would make it there as well.  While studying my map of Oklahoma, I noticed that Alabaster Caverns was actually one of a cluster of state parks in Woodward and adjacent Major Counties.  I thought maybe I could look for similar habitats in or near these other parks to see if C. celeripes might actually be more broadly distributed in northwestern Oklahoma. There was also Salt Plain National Wildlife Refuge in the area, which had impressed me during two recent October trips with its diversity of tiger beetles associated with saline habitats. Thus, I decided to head back west over the very roads that took me to the east earlier in the day.

Gloss Mountains State Park, Major Co., Oklahoma

The following day, my plan was to visit the three state parks I had seen on the map and assess their habitat – if any looked promising I would try to obtain permission to collect, and failing that I would try to hunt out similar habitats in areas adjacent to but outside of the parks. One of these parks is located on a feature called the “Gloss (Glass) Mountains,” and the highway that cut through the area was designated on my map as a scenic route.  I don’t know why this place picqued my interest above the others – perhaps it was the idea of “mountains” in Oklahoma, but I pretty much made a bee line for the Gloss Mountains in the morning.  As I approached coming from the east on Hwy 412, I saw the massive, flat-topped mesas rising above the surrounding landscape and knew, if nothing else, it would be interesting scenery.  At the entrance to the state park there was a parking lot right along the highway for a designated scenic overlook – yeah, maybe I could find some good habitat to kick around in outside of the park.  I spent some time walking along the roadsides – there was plenty of exposed clay that would be a typical situation to look for tiger beetles, but I didn’t see anything in these areas.  Across the highway there were two mesas – a small one (visible in the photo above on the left side) accessible in its entirety and another very large one (also visible in distance at center) that was accessible only on its northern flank.  I walked to the smaller one first and looked it over but didn’t find much – certainly none of the little “flashes” that I was hoping to see that would confirm a broader occurrence of C. celeripes in northwestern Oklahoma (although I did find one Dromochorus pruinina – another flightless tiger beetle that just sneaks into Missouri as a highly disjunct population).  After looking over the smaller mesa, I walked over the the large mesa and cut across the lower talus slope – much of it seemed disturbed, probably from when the highway was constructed, and still I saw little of interest. 

Cylindera celeripes macrohabitat along Hwy 412 in the Gloss Mountains. Adults were encountered primarily on lower talus slopes (lower center).

As I reached the western edge of the talus slope, I began walking along a natural drainage down towards the roadside – and I saw it!  The appearance and movement were unmistakable and didn’t fool me for a second.  I bolted straight for it and slapped at the ground as it zig-zagged erratically amongst the grass clumps before finally eluding me.  Arghh!  However, my frustration at missing the capture was completely overshadowed by my excitement at having found the species at an entirely new locality.  This prompted a much more deliberate and thorough examination of the surrounding area, and it wasn’t long before I saw another, and another…  While not quite as abundant as I had seen them at Alabaster Caverns, they certainly weren’t uncommon, and it wasn’t long before I had collected a sufficient voucher series to allow spending some time observing the behavior of the beetles in their habitat. The beetles were primarily on the lower (and milder) talus slopes and away from the roadside in more undisturbed areas.  They appeared to prefer areas of moderate vegetation cover with grass clumps spaced approximately 12-24 inches while avoiding more barren areas.  As I had observed the previous day at Alabaster Caverns, the beetles were first noticed primarily upon being disturbed by my approach as they ran from the grass clumps against which they were hiding and into the open.  They look very much like large ants when running, but the style is a little more urgent and erratic.

After several hours at this site, I decided that I should check the two other State Parks that I had seen on the map. Niether had promising habitat.  The first of these – Little Sahara State Park – lies midway along the Cimmaron River between Alabaster Caverns and the Gloss Mountains, but in contrast to the red clay/gypsum exposures that characterized Alabaster Caverns and Gloss Mountains, Little Sahara featured primarily sand substrates – great for other tiger beetles such as Cicindela formosa (big sand tiger beetle) and C. scutellaris (festive tiger beetle), but not for C. celeripes.  The other one – Boiling Springs State Park, lies in another drainage system along the Canadian River and features a wooded, riparian habitat with mostly sandy substrates along the northern slopes of the river valley (where I did spend some time looking around).  Between these parks and Gloss Mountains, however, along Hwy 412 I saw vast expanses of the same red clay/gypsum exposures that characterized the two localities where I had seen C. celeripes.  About 20 miles west of Gloss Mountains, I stopped at a rather unspectacular example of one of these exposures along the roadside – just to see if I could find the beetle in as pedestrian-looking a place as that.  I didn’t take 20 steps from the car when I saw the first one, and as before, I quickly encountered enough individuals to adequately voucher the site and allow some time for observation.  This site was very similar to Alabaster Caverns, with numerous lichens encrusting the clay substrate between the white gypsum exposures.  I looked out onto the broad expanse of clay supporting shortgrass prairie as far as the eye could see, and I knew the beetles were running around out there in untold numbers.  Cylindera celeripes not only occurs in northwestern Oklahoma, but its population is robust and likely extends throughout the red clay/gypsum exposure that characterizes the Cimarron River Valley in this part of the state.

Cylindera celeripes macrohabitat at Gloss Mountains State Park. Adults were quite common on the mesa top.

 With some time left in the day, I decided to head back to Gloss Mountains State Park – I hadn’t even looked in the park proper, and with the beetles occurring abundantly at three other nearby sites offering similar habitat, it seemed a sure bet that I would find them there as well.  The park offers no real facilities but for an incredibly scenic trail that ascends the steep southern flank of a large mesa to allow access to the top.  Once on top, it was only a matter of minutes before I saw the first beetle, and I would eventually see numerous beetles running between the grass clumps over the lichen-encrusted clay.  The views from the mesa top were spectacular as well, and only the impending dusk chased me from enjoying both the site and the beetles.  I had a tremendous feeling of satisfaction – not just from finding the beetles, but also in the newfound knowledge that the beetles were doing so well in this part of its range.

The next day I looked for tiger beetle species associated with saline habitats at nearby Salt Plain National Wildlife Refuge – that will be the subject of a future post, and it the evening I completed the drive over to northeastern Oklahoma to resume the originally planned itinerary at Tallgrass Prairie Preserve.  Like Four Canyon Preserve, this TNC property is heavily managed with prescribed burns to maintain diversity of the prairie flora and prevent invasion by woody plants.  And likewise I observed verdent seas of grass interspersed with classic prairie forbs – and few insects.  I won’t blame this on the burns because I lack any empirical basis for making such claim.  However, each visit I make to freqently burned prairies further increases my skepticism that the invertebrate fauna isn’t somehow being impacted.  The lack of litter and absence of lichens on the soil surface results in an almost ’sterile’ look that I don’t see in areas where fires occur with less frequency. I looked at a few different places within the vast preserve but didn’t find much, and midday I sighed and began the 7-hour drive back to St. Louis.  The trip was over, and so was the hunt for C. celeripes. Or so I thought… (to be continued).

Copyright © Ted C. MacRae 2009

Revisiting the Swift Tiger Beetle – Part 1

Photo 1 - Cylindera celeripes at Alabaster Caverns State Park in northwestern Oklahoma.

When my hymenopterist friend, Mike Arduser, came back from his first trip to Oklahoma’s Four Canyon Preserve last September, my first thought upon seeing his photos of the area was, “Ooh, that looks like a good place for tiger beetles!” Its rugged red clay and gypsum exposures reminded me of similar country I had seen in the not-too-distant Gypsum Hills of south-central Kansas, where I was fortunate enough to observe a nice population of the fantastically beautiful Cicindela pulchra (beautiful tiger beetle) back in 2005. When I later realized that the area was only 30 miles southwest of a confirmed recent sighting of Cicindela celeripes (swift tiger beetle, now Cylindera celeripes), I thought, “Ooh, I wonder if celeripes might occur there also.”

Photo 2 - Cylindera celeripes on lichen-encrusted clay soil at Alabaster Caverns State Park.

Recall that C. celeripes is one of North America’s rarest and least understood tiger beetles. This tiny, flightless, ant-like species has been recorded historically from eastern Nebraska south to north-central Texas, but its range appears to have become highly restricted over the past century. It hasn’t been seen in Nebraska for nearly 100 years now, and most recent records have come from its last known stronghold in the Flint Hills of Kansas. In 2003, however, a photographer by the name of Charles Schurch Lewallen posted on BugGuide a photograph of this species taken at Alabaster Caverns State Park in northwestern Oklahoma, and last year small numbers of adults were seen in the Loess Hills of western Iowa. This last sighting triggered an immediate trip to the site by myself and Chris Brown, who has been co-investigating the tiger beetle fauna of Missouri with me for several years now. The occurrence of this species in Iowa’s Loess Hills had reignited our hopes – faint as they were – that the beetle might yet occur in extreme northwestern Missouri, where the Loess Hills reach their southern terminus. We wanted to see the beetle in the wild to better understand its habitat requirements before resuming our search for this species in northwestern Missouri. We succeeded in finding the beetle – an amazing experience in itself – and brought three adults of this never-before-reared species back to the lab for photographs and an attempt at rearing. We did manage to obtain viable eggs, but we were not successful in rearing the larvae beyond first instar. I wrote about that experience last August in a post entitled, “The hunt for Cicindela celeripes” (that post is now currently in press as an article in the journal CICINDELA).

Photo 3 - Cylindera celeripes on gypsum exposure at Alabaster Caverns State Park.

Thus, when my friend Mike asked me earlier this year if I might be interested in joining him on his return trip to Four Canyon Preserve in June, I jumped at the chance. I figured I could look for celeripes at the preserve, and if I failed to find it there then I would go to Alabaster Caverns and see if I could relocate the beetle where it had been photographed in 2003. My goals were modest – I simply wanted to find the beetle and voucher its current presence in northwestern Oklahoma (and if possible photograph it in the field with my new camera!). Before leaving, I wrote to Charles Lewallen, who graciously responded with details regarding the precise location and time of day that he had seen the beetle at Alabaster Caverns, and on the first Friday of June I followed behind Mike and his lovely wife Jane during our ten-hour drive out to Four Canyon Preserve. For three days, I roamed the mixed-grass prairie atop the narrow ridges and dry woodland on the steep, rugged canyon slopes of the preserve – always on the lookout for that telltale “flash” between the clumps of bluestem and grama, ever hopeful that one would prove not to be the ant or spider that it appeared to be (and, indeed, always was). Many tiger beetles would be seen – chiefly the annoyingly ubiquitous Cicindela punctulata (punctured tiger beetle), but celeripes would not be among them. Whether this is due to historical absence from the site or a more recent consequence of the wildfires that swept the area a year earlier is hard to say, but its absence at Four Canyon meant that I would need to make a quick, 1-day detour to Alabaster Caverns before rejoining Mike and Jane at Tallgrass Prairie Preserve in northeastern Oklahoma, where we planned to spend the second half of the week.

Photo 4 - Cylindera celeripes on gypsum exposure at Alabaster Caverns State Park.

Arriving at Alabaster Caverns I was filled with nervous, excited anticipation. Would I find the species, as Charles Lewallen had, or would I get skunked? I kitted up and started walking towards the area where Charles wrote that he had seen the beetle, noting the annoying “Removal of plants and animals prohibited” sign along the way. I hadn’t taken ten steps off the parking lot when I saw it! I froze at first, hardly believing that I had found it that quickly, then started watching the tiny beetle as it bolted urgently from one grass clump to the next. Recalling my experience with this beetle in Iowa (and fearing I would lose it amongst the vegetation), I captured the specimen and placed it live in a vial – I would talk to the park staff later about taking the beetle, but for now I needed to guarantee I had a backup for the lab in case I was unable to get field photographs of the beetle. I started walking again, and within a few minutes I saw another one – okay, they’re here in numbers. I carefully took off my camera bag and assembled the components, all the while keeping my eye on the beetle, and then I began trying to do what last year had seemed impossible – getting field photographs. It was easier this time – the vegetation was not so dense, so I could keep an eye on the beetle as he darted from one clump to another. I tried to wait until he settled in an open spot, but it soon became apparent that just wasn’t gonna happen without a “helping” hand. I started blocking the path of the beetle as he tried to dart away and then removing my hand to see if he would stay put. There were a few false starts, where the beetle looked like he would sit still and then dart just as I was set to take the shot, but eventually it wore down and started sitting still long enough for me to shoot a few frames. Torn between the need to get as many photographs as possible and the desire to look for more beetles, I decided to look around more to see how common the beetle was. As I walked out into the shortgrass prairie above the canyons, I began to see adults quite commonly. Most often they were seen as they bolted out into the open from a clump of vegetation when disturbed by my approach. The substrate was red clay and gypsum – just as I had seen in Four Canyon Preserve, but unlike that area the clay exposures were heavily colonized by a mottling of green, blue, and gray lichens. It made the beetles almost impossible to see when they were not moving – even at close range! I spent about an hour taking photographs of several individuals, even managing to photograph one that appeared to be parasitized by what I take to be a dryinid hymenopteran.

Photo 5: Cylindera celeripes with parasite (dryinid hymenopteran?). Note also the ant head attached to right antenna.

After getting a sufficient series of photographs (is there really such thing?), I went to the park office hoping to convey the significance of this find to the Park Naturalist and to convince him/her to let me take some live individuals with me for another attempt at rearing. The Park Naturalist was out of the office, but the Park Historian was there. I could hardly contain my excitement as I explained to her what I had found, why it was so important, and my hope to try to rear the species with adults collected in the field. She not only responded as positively as I had hoped, but accompanied back out into the field so that I could show her the beetles. She told me it would be no problem to take some live individuals for rearing and to please let them know if there was anything else they could do to help me.  She then provided me with the day’s natural history “dessert” by pointing out a Mexican free-tailed bat (Tadarida brasiliensis) – Oklahoma’s state flying mammal – roosting up in the top of a nearby picnic shelter. Standing atop the picnic table put me within arm’s length of the little chiropteran – close enough to see his tiny little eyes looking quizzically back at me.

Photo 6 - Cylindera celeripes macrohabitat at Alabaster Caverns State Park. Note rather widely spaced clumps of vegetation.

It had begun sprinkling rain by then, so with some urgency I got my tools, extracted a couple of chunks of native soil and transferred them to the small “Critter Totes” that I had brought for the purpose, and began searching for live individuals to place within them. The beetles had become scarce as the drizzle turned to light rain, and by the time I had split about a dozen individuals between the two containers the rain was coming down hard enough to start puddling. I continued a last ditch effort to find “just one more,” but a lightning strike within a mile of the park put an end to that – the air now felt electric as I hurriedly walked back to the car (gloating unabashedly inside) and began the three-hour drive towards Tallgrass Prairie Preserve… (to be continued).

Photo 7 - Cylindera celeripes microhabitat at Alabaster Caverns State Park. Note thick encrustation of lichens on clay substrate amidst white gypsum exposures.

Photo details:
#1-3, 5: Canon 100mm macro lens w/ 68mm extension on Canon EOS 50D, ISO 100, 1/250 sec, f/13 (photo 3, f/11), MT-24EX flash 1/4 power through diffuser caps.
#4: Same except Canon 65mm 1-5X macro lens, flash 1/8 power.
#6: Same except Canon 17-85mm zoom lens (17mm), 1/64 sec, f/8, natural light.
#7: Same except Canon 17-85mm zoom lens (35mm), 1/100 sec, f/7, natural light.

Copyright © Ted C. MacRae 2009

Friday flower

Photo details: Canon MP-E 65mm 1-5X macro lens on a Canon EOS 50D, ISO 100, 1/250 sec, f/16, MT-24EX flash 1/8 power through diffuser caps

While photographing small Acmaeodera beetles on flowers of Tradescantia ohioensis at Packsaddle Wildlife Management Area, I thought I should take a photo of the flower itself.  Flowers of Tradescantia species, or spiderworts, are notable for their bright yellow anthers and filaments with numerous hairs. Each of the (usually) six stamens possesses around 70-100 hairs, which in turn are composed of a chain of about 20 large, single cells that are purple in color and contain a large, water-filled central vacuole. The cells can be seen easily with low magnification – click on the photo to see the larger version, with the individual cells that make up each hair clearly visible. I haven’t been able to ascertain the function of these hairs for the plant, but their usefulness in observing division in plant cells (the flowing cytoplasm and nucleus can be seen easily) and their sensitivity to radiation and chemical mutagens have been recognized for many years. The hairs turn pink when exposed to radiation, allowing them to be used as a sort of ‘natural’ Geiger counter.

Update: While writing this post, I sent an email to George Yatskeivych, botanist at the Missouri Botanical Garden and author of Steyermark’s Flora of Missouri (1999, 2006), asking if he knew the function of the filamental hairs.  After reading his response (below), I don’t feel quite so bad for not being able to determine the answer myself:

I don’t know that I have ever heard anyone express a particular use for the hairs on the filaments of Tradescantia species.  Sometimes, hairy filaments help to trap pollen from visiting insects in proximity to the stigma or act as nectar guides, but I do not think that anyone has determined such “uses” in Tradescantia.  There may not be a selective advantage to hairy filaments in the genus.

If any botanist happens to read this post and has some insight about this, a comment would be most appreciated.

REFERENCES:

Yatskievych, G. 1999. Steyermark’s Flora of Missouri, Volume 1. Missouri Department of Conservation, Jefferson City, 991 pp.

Yatskievych, G. 2006. Steyermark’s Flora of Missouri, Volume 2. The Missouri Botanical Garden Press, St. Louis, 1181 pp.

Copyright © Ted C. MacRae 2009

A Silver Anniversary

Twenty-five years ago tomorrow, I discovered my first new species.  I didn’t know it at the time – in fact, it would be several years later before the budding, young entomologist that I was would finally conclude that the large, spectacularly beautiful, cerambycid beetle that I was capturing in my fermenting bait traps just south of St. Louis did indeed represent a previously unrecognized species.

In my first job out of school as a field entomologist for the Missouri Department of Agriculture, I worked with nursery growers to identify insect pest problems on their crops and provide recommendations for control.  Wood boring beetles – especially the longhorned beetles – are a major problem for growers of trees, and it was that importance, combined with a latent interest in taxonomy, that led to my interest in this group (and the beginnings of my identity as a “coleopterist”).  I didn’t just work in entomology – I lived it, and when I wasn’t inspecting rows of trees, checking gypsy moth traps, or scouting for musk thistle weevil release sites in the three counties around St. Louis, I was collecting insects and the primary literature about them.  One of the early papers I came across (Champlain and Knull 1932) described the use of fermenting bait traps for collecting Cerambycidae, in particular species in the genus Purpuricenus.  I desperately wanted some of these beetles – large, showy, velvety black, with vivid red or orange basal markings on the elytra – but had not yet encountered either of the two species then known in eastern North America.   I made a batch of the stuff – basically molasses, beer, yeast, and water - and placed buckets of the slurry at a few spots that I would be able to check periodically while on my rounds.  Much to my delight, I quickly began trapping numerous species of Cerambycidae – including the two species of Purpuricenus.  Most of these specimens were coming to a trap I had placed at one of my favorite collecting spots – Victoria Glades Natural Area in Jefferson Co., some 30 miles south of St. Louis.  Over the next few weeks I acquired a nice little series of the two species, and I increased their number during the following three years with continued trapping.

Purpuricenus humeralis (Fabricius)

The two species were easily distinguished – in Purpuricenus humeralis the basal elytral markings were triangular and covered just the humeri, while in P. axillaris they were transverse and covered the entire basal half of the elytra.  As I studied the series of the latter, however, something seemed amiss.  Some of the specimens were distinctly larger and more robust, while others were smaller and more gracile.  Moreover, the color of the elytral markings on the larger specimens seemed to be consistently more reddish than the pale orange markings of the smaller specimens.  At first I dismissed it as variation – common among longhorned beetles, which can vary greatly in size depending on the quality of the larval host.  But as I studied them more I noted other consistent differences between the two “forms” - the larger with more well-developed pronotal tubercles (the middle one of which bore a distinctly polished apex and the lateral ones more acutely angled), a distinct “tooth” at the apex of the elytral midline, and coarser punctures at the base of the elytra.  It seemed obvious that the two forms represented two different species, but the only other species I could find in Linsley’s (1962) monograph of North American Cerambycidae (my bible!) was P. linsleyi – known then only by the holotype and one paratype from an unspecified location in Texas.  Neither series matched the description of that species very well – the shape of the elytral marking was wrong – but I concluded the larger one must be that species and the smaller was axillaris.  There was another possibility – but that young entomologist just couldn’t entertain the idea of a large, showy, longhorned beetle still undescribed in eastern North America.

Purpuricenus axillaris Haldeman

Some time later I received a series of a Purpuricenus that my colleague Dan Heffern had collected near San Antonio, Texas.  Dan had also taken up collecting cerambycids with fermenting bait traps, and while he was quite proficient with Texas species he wasn’t quite sure what to make of these particular specimens.  He sent them to me for my opinion, and it was quite clear – they were the real P. linsleyi.  The rediscovery of that rare species was an exciting find in itself, but it rekindled the puzzle of the Missouri Purpuricenus – if they were not P. linsleyi, then what were they?  The only conclusion was that two species were masquerading under a single name, and that I would have the priviledge of naming one of them.  Wow, my first new species – something every amateur taxonomist dreams about, but I had no idea it would happen so soon, or with such a spectacularly beautiful species!  By then I was living in Sacramento, so I traveled to nearby Berkeley to meet with the late John Chemsak at the University of California and show him my material.  John was a longtime associate of the late, great E. Gorton Linsley, co-authoring with Linsley several later volumes of the North American Cerambycidae monograph, and had managed to borrow type material of P. axillaris from the Museum of Comparative Zoology at Harvard University.  We found that both species were present in the small types series, so together we decided which specimen should be designated as a lectotype for P. axillaris – and thus, which of the two species would be named as new. 

Purpuricenus paraxillaris MacRae

It would take several more years before I actually published a description of the new species, naming it P. paraxillaris (meaning “near” axillaris) and selecting as holotype the very first specimen I collected – on June 25, 1984.  I wanted to know its distribution, which meant borrowing material from museums and willing individuals.  I also recognized that some collectors of Cerambycidae might view the description of a large, showy species from eastern North America with some skepticism, so I wanted to be as thorough as possible.  (There were a few private collectors that declined to loan their material to me because of such skepticism.)  During that process, I learned that P. paraxillaris is quite common across the eastern U.S. – in fact, many of the literature references to P. axillaris actually refer to this species, but it wasn’t until collectors began using fermenting bait traps widely that large series of specimens became available for study.  By examining the few available reared specimens, I learned that P. axillaris prefers hickory (Carya) as a host, while P. paraxillaris prefers oak (Quercus) and chestnut (Castanea).  With several hundred specimens of the two species at my disposal, I became more convinced than ever that they were distinct, and with the many specimens of other species in the genus that I had borrowed as well, I decided to expand the scope of the paper to a general review of the entire genus in North America.  This would allow me not only to describe the new species, but report the rediscovery of P. linsleyi as well.  Finally, after several years (remember, I was/am just an amateur), the description was published in the October 2000 issue of The Pan-Pacific Entomologist (MacRae 2000).

For those of you with an interest in such things, I include here a key to the three eastern North American species of Purpuricenus.

Key to adult Purpuricenus in eastern North America 
(adapted from MacRae 2000)

1.         Posterior margin of basal elytral markings distinctly oblique; apical dark area extending forward along suture and reaching scutellum; …………………………………………………………………………………………….. P. humeralis (Fabricius)

1′.        Posterior margin of basal elytral markings more or less transverse; apical dark area not extending forward along suture to scutellum ………………….. 2

2 (1′).   Discal calluses of pronotum weak, median callus without polished apical line; lateral pronotal tubercles small, angles obtuse; basal elytral punctation relatively finer and sparser; elytral apices subtruncate, angles not distinctly dentate; basal elytral markings yellow to orange ………………………………………………………………………………………………… P. axillaris Haldeman

2′.        Discal calluses of pronotum distinct, median callus prominent and with polished apical line; lateral pronotal tubercles well developed, angles acute; basal punctation of elytra relatively coarser and denser; elytral apices emarginate, angles distinctly dentate; basal elytral markings orange to red-orange ………………………………………………………………………………….. P. paraxillaris MacRae

REFERENCES:

Champlain, A. B. and J. N. Knull. 1932. Fermenting bait traps for trapping Elateridae and Cerambycidae (Coleop.). Entomological News 43:253–257.

Linsley, E. G. 1962. The Cerambycidae of North America. Part III. Taxonomy and classification of the subfamily Cerambycinae, tribes Opsimini through Megaderini. University of California Publications in Entomology 20:1–188, 56 figs.

MacRae, T. C. 2000. Review of the genus Purpuricenus Dejean (Coleoptera: Cerambycidae) in North America. The Pan-Pacific Entomologist 76:137–169.

Copyright © Ted C. MacRae 2009

Four Canyon Preserve, Oklahoma

Looking SE into lower Horse Canyon towards Canadian River

On my recent week-long collecting trip, the first three days were spent at Four Canyon Preserve in far northwestern Oklahoma.  This nearly 4,000-acre preserve features a stunning landscape of rugged, wooded canyons dissecting ridges of mixed-grass prairie which provide critical habitat for several rare plants and animals.  Despite years of overgrazing, fire suppression, and invasion by exotic plants, The Nature Conservancy (TNC) recognized the restoration potential of this landscape and began management practices to restore its ecological function and integrity after acquiring it in 2004.  The land was rested until April 2008, at which time a wildfire swept through the area and burned approximately 90% of the property.  This event was actually welcomed by TNC, who was already in the process of initiating a prescribed burn – they simply pulled back and let it rip!  The burn, combined with mechanical removal of eastern redcedar (Juniperus virginiana) that had invaded many areas of the preserve, did much to confine woody growth to the canyons proper, and good rains during the past two springs following that burn have resulted in a lush, green, diverse landscape brimming with prairie wildflowers.  The vivid contrast between the green vegetation and the red clay canyons with their white gypsum exposures has created spectacular vistas of a rugged landscape.  This year, cattle have been reintroduced at low levels to simulate the irregular, patchy disturbance experienced in pre-settlement times when native grazers (bison and elk) dotted the landscape.

The flora (Hoagland and Buthod 2007) and avifauna (Patten et al. 2006) of the preserve are well characterized, but (as nearly always seems the case) arthropod and other micro faunas need much additional study.  My hymenopterist colleagues and I were welcomed enthusiastically by TNC staff, who are anxious to incorporate the results of our insect surveys into an overall fauna.  Apoid hymenopterans appear to have benefited greatly from the recent rejuvenation of the preserve’s floral character.  Results for the beetle populations that I encountered, however, were more mixed. Certain groups, such as scarabaeine dung beetles, were quite abundant and diverse (due to the reintroduction of cattle), but others, including the tiger beetles, jewel beetles, and longhorned beetles that I was most interested in finding, existed at rather low and not very diverse levels.  I had hoped to find the very rare Cylindera celeripes (swift tiger beetle) running amongst the clumps of vegetation on the preserve’s red clay exposures but instead saw only the ubiquitous Cicindela punctulata (punctured tiger beetle), and the few jewel beetles that I managed to beat off the lower branches of hackberry (Celtis laevigata) and soapberry (Sapindus saponaria var. drummondii) trees were found only in the small parts of the preserve that escaped last year’s burn.  This seems fairly typical – I generally don’t find many insects in these groups whenever I survey areas that have experienced a significant amount of recent burning.  Some ecologists might take exception to this statement, and they would have little difficulty citing studies that show rapid recolonization of prairies by a majority of prairie insect specialists within two years after a prescribed burn.   Nevertheless, the impact of prescribed burning on invertebrate populations and its potential for causing local extirpations has become a contentious issue among ecologists and entomologists in recent years.  While my experience hardly passes for rigorous investigation, I am becoming increasingly convinced that a certain amount of caution is warranted when designing burn management plans for prairie relicts.

I’ll discuss more about the beetles and other insects (and even some vertebrates) that I saw during my three-day visit to Four Canyon Preserve in future posts.  In the meantime, I share with you some of my photos of this spectacularly beautiful landscape (note the abundance of woody cadavers from last year’s burn in some of the photos).

Looking S into upper reaches of Mulberry Canyon

Looking S into upper reaches of Mulberry Canyon

Looking E across upper Harsha Canyon

Looking SE into Harsha Canyon towards Canadian River

Looking E across lower Harsha Canyon

Looking NE towards Mulberry Canyon bluffs from Canadian River valley

REFERENCES:

Hoagland, B. W., and A. K. Buthod.  2007.  Vascular flora of the Four Canyons Preserve, Ellis County, Oklahoma.  Journal of the Botanical Research Institute of Texas 1(1):655–664.

Patten, M. A., D. L. Reinking, and D. H. Wolfe.  2006.  Avifauna of the Four Canyon Preserve, Ellis County, Oklahoma.  Publications of the Oklahoma Biological Survey (2nd Series) 7:11-20.

Copyright © Ted C. MacRae 2009