tiger beetles

Revisiting the Swift Tiger Beetle – Part 3

/ Ted C. MacRae / 18 Comments

…continued from Revisiting the Swift Tiger Beetle – Part 2.

The Oklahoma trip had been an unqualified success. Not only had I managed to find the rare Cylindera celeripes (swift tiger beetle) at Alabaster Caverns, I had also determined the population there was healthy and, in fact, occurred robustly across a large swath of red clay/gypsum hill habitat in the vicinity of the Cimarron River (Woodward and Major Counties) in northwestern Oklahoma. This is good news for the species, who some have regarded as a potential candidate for federal listing on the endangered species list. There is no doubt that the species has suffered greatly in many parts of its range during the past century – most likely due to loss of habitat; however, the presence of a strong population in Oklahoma gives reason for optimism about its long-term prospects. It would have been even better had I found the species at the two Nature Conservancy preserves (Four Canyon and Tallgrass Prairie) that I had targeted, and the reasons for its apparent absence at those two sites despite an abundance of apparently suitable habitat remain a mystery to me (although I have my suspicions). Nevertheless, I returned to St. Louis happy, with new localities in my database and live individuals in containers of native soil for another attempt at rearing.

Our work with this species was not done, however. While C. celeripes has never been recorded in Missouri, my colleague Chris Brown and I have long suspected that it might occur here – most likely, we felt, in extreme northwestern Missouri where the Loess Hills landform reaches its southern terminus. We had looked for it in this area a few times before on the few remaining dry, hilltop prairie relicts that are so common further north in Iowa, and we had also looked for it in the larger tallgrass prairie remnants of west-central Missouri. None of these searches were successful, and with each unsuccessful effort it seemed less and less likely that the species actually occurred within the state – especially considering the declines that the species has experienced throughout its range. However, when we managed to find a small, newly discovered population of the species last summer in the Loess Hills of southwestern Iowa, just 60 miles north of Missouri (see The Hunt for Cicindela celeripes), we decided that one more thorough effort to locate the species in Missouri was in order.

Star School Hill Prairie Natural Area (north tract), Atchison Co., Missouri.

Star School Hill Prairie Natural Area (north tract), Atchison Co., Missouri.

Our plan was straightforward – we would travel to northwestern Missouri each weekend beginning in late June and search the most promising hilltop prairie relicts that still remain in Missouri. There aren’t many of these, so I contacted Tom Nagel of the Missouri Department of Conservation – who probably knows more about Missouri’s hilltop prairie relicts than anyone else – for assistance in identifying these parcels. Tom graciously sent me descriptions and aerial photographs of the highest quality relicts still remaining in Missouri. None of these are large (12 contiguous acres or less), and all have been impacted to some degree by woody encroachment and are in various stages of restoration. We had already searched one of these tracts (Star School Hill Prairie) a few times, but two others were new to us. So, on a Friday evening before the first of three planned weekends for our study (and only two weeks after returning from Oklahoma), Chris and I made the long drive across Missouri and north along the Missouri River and began our search the next morning.

Fieldmate Chris Brown surveys loess hilltop prairie habitat at Star School Hill Prairie Natural Area, Atchison Co., Missouri

Fieldmate Chris Brown surveys loess hilltop prairie habitat at Star School Hill Prairie Natural Area (south tract), Atchison Co., Missouri

Our first stop was High Creek Hill Prairie in Brickyard Hill Conservation Area (Atchison Co.). We had been to Brickyard Hill a few times but had not previously found this particular hilltop prairie. We found the tract, a long, narrow series of ridge tops and southwest-facing slopes, thanks to Tom Nagel’s map and began searching with all the enthusiasm and optimism that accompanies any new search. Our optimism waned with each hilltop ridge that we traversed not seeing the beetle, until we reached the easternmost ridge amidst a jumble of eastern red-cedar cadavers that halted any further progress or promise. As we stood atop that last hill, we debated our next move. Chris had noted apparently good habitat on the lower slopes below us, while I had spotted another very small hilltop tract across a wooded ravine and disjunct from the main prairie. We decided these areas should be explored before moving on to the next site, but as we searched those lower slopes our optimism continued to wane. The habitat was perfect based on what we had seen in Iowa last year and what I had seen in Oklahoma earlier in the month – small clay exposures amongst clumps of undisturbed little bluestem and grama, but still no beetles. Chris, refusing to accept defeat, continued to search the slope, while I worked my way over to the smaller hilltop tract I had seen from above. After crossing through the wooded ravine, I found an old 2-track running along the base of the tract and began walking along it. The small slope above the 2-track was littered with large cadavers of the invasive eastern red-cedar (Juniperus virginiana), apparently left in place after chainsawing to provide fuel for a planned, future burn. As I walked, a white-tailed deer bolted from a nearby cadaver, giving me a bit of a start, and I veered towards the cadaver to have a look at where it had bedded down. By this time I almost wasn’t even really thinking about C. celeripes anymore – we had been there for about an hour and a half and searched the most promising habitats without success – the small tract where I was now working was almost a last gasp before moving on. As I approached the deer’s bedding site, a “flash” in the thick vegetation caught my eye, and I knew instantly what it was. Immediately I dropped to my knees and tried to “trap” the evasive little beetle (I’ve found that forming a “trap” between the crotches of my hands and gradually closing my hands together forces the beetle to run up and over one of my hands, at which time I can try to pin it down with my other). The beetle behaved exactly as expected, running over my left hand – but I missed it. I trapped it again, and once again it ran over my hand too fast to pin down. I tried to follow it as it zigzagged erratically through the thick vegetation, but in the blink of an eye it was gone. I spent the next several minutes frantically pulling apart the vegetation in a 2-foot radius around the spot in what I knew was a vain attempt to relocate the beetle before ultimately accepting that I had missed it. No matter – I had seen it and had absolutely no doubt about what it was – C. celeripes does indeed occur in Missouri! Wow – big news! I knew if I had seen one, I had a good chance of seeing another, so I began searching the area again – now with much more deliberation. I walked back and forth along the old 2-track, up and down the cadaver-littered slope, and back to the original spot several times. As time passed, a gnawing fear began to grow inside me that this new state record might lack a voucher. Suddenly, very near the original spot, I saw another. This time I pounced with authority and made no mistakes, and after securing the live beetle in a vial I gloated and congratulated myself unabashedly inside while bursting to give the news to Chris. I searched the slope some more, but I couldn’t take it anymore – I had to tell someone. I pulled out my cell phone and began texting a message to my daughter Mollie (who really doesn’t care about beetles but loves to receive text messages). As I was texting, Chris appeared on the lower slope, obviously noting that my net had been left on the ground purposely to mark a spot. As I finished texting I told Chris to come here, I wanted to show him something, and then non-chalantly handed him the vial. I would give anything to have a video of the look on Chris’ face as it changed from quizzical dumbfoundedness to shocked elation. Chris, too, had reached a low point in his optimism after thoroughly searching the previous slope without success, but now we were both as giddy as school boys – our long efforts had finally paid off with a new state record for one of North America’s rarest tiger beetles (the way we were acting, you’d have thought we’d just discovered plutonium!). We searched the slope for another half hour or so, with Chris seeing one more individual very close to where I had seen the first one. Whether it was the same or a different individual is unknown, so we decided that we had seen at least two individuals at this site. The discovery of C. celeripes here caused us to once again search the lower slope that Chris had previously searched so thoroughly, but again the beetle was not seen. Our giddiness was beginning to give way to concern over the few individuals we had seen and how localized they seemed to be. We had been at the site now for about three hours, and I was famished. I hiked back to the truck, noting some habitat at the far western end of the main prairie where we had begun our search that looked like it deserved another search. As I ate, Chris worked his way over to that spot, and after a period of time I heard him yell down to me and give me the “thumbs up.” I hurriedly finished eating and worked my way up to where he stood, and together we located two more individuals – taking one as a voucher for the site and ganging up on the other to keep it pinned into an open area where each of us could take field photographs before we finally let it “escape.” Seeing the species on the larger parcel had relieved our concern a little bit, and we felt a little less worried about its status here now.

Cylindera celeripes - High Creek Hill Prairie, Brickyard Hill Conservation Area, Atchison Co., Missouri (new state record)

Cylindera celeripes - High Creek Hill Prairie, Brickyard Hill Conservation Area, Atchison Co., Missouri (new state record)

Later in the day we would see the species again at Star School Hill Prairie Natural Area , the northernmost substantial loess hilltop prairie within Missouri, and one that we had searched at least twice previously for the species. Again, we saw only two individuals in almost three hours of searching, confirming the impression first gained at Brickyard Hill that the species is not present in very high densities. Like Brickyard Hill, the beetles at this site were found in areas of undisturbed hilltop prairie with moderately thick shortgrass vegetation and were seen only when they IMG_0789_1200x800ran from one grass clump to another after being disturbed by our approach. We also looked for it at a smaller disjunct parcel just to the north, but the lateness of the hour limited the time we had to explore this site. Star School Hill Prairie is some 6 miles north of Brickyard Hill, thus, finding C. celeripes at two sites not in close proximity increased our optimism that the species might actually occur in many of the loess hilltop prairie remnants still remaining in northwestern Missouri. This optimism was further increased the next day when we saw two more individuals at one of Missouri’s southernmost hilltop prairie relicts at McCormack Loess Mounds Natural Area in Holt Co. However, our optimism is tempered by the fact that, again, we saw only two individuals, both of which were seen in a small, unburned spur extending northward off the main prairie, while none were seen in the much larger main parcel that appeared to have been recently burned in its entirety.

Cylindera celeripes macrohabitat at Star School Hill Prairie. Beetles were seen along the narrow trail in the foreground and on the mild upper slopes (below bur oak in upper left).

Cylindera celeripes macrohabitat at Star School Hill Prairie. Beetles were seen along the narrow trail (foreground) and on the mild upper slopes (below bur oak, upper left).

The presence of this rare Great Plains species in Missouri’s critically imperiled hilltop prairies is cause for both excitment and concern. Cylindera celeripes represents a unique and charismatic addition to the state’s rich natural heritage. However, like soapweed yucca (Yucca glauca var. glauca), skeletonweed (Lygodesmia juncea), and the dozen or so other plant and animal species of conservation concern found within the hilltop prairies of IMG_0774_1200x800Missouri’s Loess Hills, C. celeripes appears to be entirely dependent upon these habitats for its survival within the state. Ensuring its continued survival will require careful reconsideration of the management approaches used for these rapidly shrinking natural communities. Prescribed burning has been and will continue to be an important tool in restoring our hilltop prairies; however, nonjudicious use of fire could lead to local extirpaton of C. celeripes within these habitats. Should that occur, recolonization from nearby parcels is unlikely due to the small, highly disjunct, and upland character of Missouri’s hilltop prairie remnants and the flightless nature of C. celeripes. As a result, rotational cool-season burns should be utilized as much as possible to avoid localized extirpations, especially on smaller parcels (Panzer 2002).

Hilltop prairie at McCormack Loess Mounds Natural Area, Holt Co., Missouri. The main tract (pictured) was recently burned - beetles were found in a small unburned spur (off left center).

Hilltop prairie at McCormack Loess Mounds Natural Area, Holt Co., Missouri. The main tract (pictured) was recently burned - beetles were found in a small unburned spur (off left center).

Photo details:
Beetles: Canon 100mm macro lens w/ 68mm extension on Canon EOS 50D, ISO 100, 1/250 sec, f/18, MT-24EX flash 1/2 power through diffuser caps.
Landscapes: Same except Canon 17-85mm zoom lens (17mm at Star School, 20 mm at McCormack), 1/60 sec, f/8-9 (Star School) or f/13 (McCormack), natural light.

REFERENCE:

Panzer, R. 2002. Compatibility of prescribed burning with the conservation of insects in small, isolated prairie reserves. Conservation Biology , 16(5):1296-1307.

Copyright © Ted C. MacRae 2009

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Revisiting the Swift Tiger Beetle – Part 2

/ Ted C. MacRae / 10 Comments

…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.

IMG_0620_1200x800

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

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.

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

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Revisiting the Swift Tiger Beetle – Part 1

/ Ted C. MacRae / 15 Comments
Photo details: Canon 100mm macro lens with 68mm extension on a Canon EOS 50D, ISO 100, 1/250 sec, f/13, MT-24EX flash 1/4 power through diffuser caps

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 details: Canon 100mm macro lens with 68mm extension tube on a Canon EOS 50D, ISO 100, 1/250 sec, f/13, MT-24EX flash 1/4 power through diffuser caps

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 details: Canon 100mm macro lens with 68mm extension tube on a Canon EOS 50D, ISO 100, 1/250 sec, f/11, MT-24EX flash 1/4 power through diffuser caps

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 details: Canon 65mm 1-5X macro lens on a Canon EOS 50D, ISO 100, 1/250 sec, f/13, MT-24EX flash 1/4 power through diffuser caps

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.

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, Alabaster Caverns State Park, Oklahoma. Note rather widely spaced clumps of vegetation (photo details: Canon 17-85mm zoom lens (17mm) on a Canon EOS 50D, ISO 100, 1/64 sec, f/8).

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).

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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

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Treatise of Western Hemisphere “Cicindelitae”

/ Ted C. MacRae / 5 Comments
Sumlinia hirsutifrons

Sumlinia hirsutifrons (Sumlin). Copyright © T. L. Erwin and D. L. Pearson 2008

ResearchBlogging.orgTiger beetles have long enjoyed a popularity that is disproportionate to their diversity, abundance, and economic importance relative to other groups of beetles. This seems as much due to their charismatic behavior – toothy jawed predators in extreme habitats – as it is to their brilliant colors, dazzling designs, and penchant for polytopism. Never before has this popularity been more evident than in the past decade, during which time there has been a veritable explosion of popular and semi-popular tiger beetle books. Barry Knisley and Tom Schulz (1997) got things going with their regional guide to species occurring in the southeastern U.S., followed closely by a similar guide to the northeastern U.S. (Leonard and Bell 1998).  Both of these books featured color photographs of all species treated and supplemented species treatments with sections on biology, natural history, rearing, and conservation.  No longer were avocational or professional entomologists forced to consult dry, technical treatments in primary journals for information on these anything-but-dry, boring beetles.  These two books were, in turn, followed by several smaller regional treatments, including John Acorn’s (2001) eccentric and highly entertaining Tiger Beetles of Alberta and Paul Choate’s (2003) alternative treatment of Florida species (a silly little article about Missouri’s two dozen or so species also appeared in 2001), as well as a comprehensive summary of the group’s ecology and evolution by Dave Pearson and Alfreid Vogler (2001).  The granddaddy of all tiger beetle books – at least for U.S. cicindelophiles – appeared a few years later in the form of A Field Guide to the Tiger Beetles of the United States and Canada, by Dave Pearson and colleagues (2006).  At long last, keys, photographs, and discussions of habitats, biology, and variation of every species and subspecies known from the U.S. and Canada could be found in a single source.

The latest contribution to this growing body of literature is the most comprehensive yet.  In it, Dave Pearson has teamed up with ground beetle expert and lead author Terry Erwin to provide a synthesis of every species of tiger beetle known to occur in the Western Hemisphere.  Erwin and Pearson (2008) is a beautifully printed and handsomely bound treatise that elaborates the current classification, taxonomy, distribution at the country and/or state/provincial level, and way of life of each species and subspecies, including comments on habitats, flight and dispersal capabilities, seasonal occurrence, and behavior.  References for each species and an extensive bibliography are also provided, as are notes on threatened and endangered species and subspecies.

There is much to like about this book.  The scope of coverage to include the entire Western Hemisphere is unprecedented – few insect taxa, even popular ones, have been treated so expansively.  Those without access to comprehensive libraries of primary tiger beetle literature will appreciate having all of the available information in one book, while those with access to the literature will appreciate the references for individual species.  Even those whose interest is restricted to the North American fauna will find the historical nomenclature handy – something lacking in Pearson et al. (2006).  As a bonus, a full color plate is offered for each genus that offers a spectacular extended focus image of a representative species, along with additional photographs provided by a number of contributors (I myself provided some of the photographs used in the Cylindera and Dromochorus plates) of live beetles and their habitats.  Collectively, these images provide a comprehensive look at the diversity and habitats of New World tiger beetles that has until now not been available.

The book, however, is not without its criticisms.  There has long been controversy within the Tiger Beetle Guild regarding the relationship of tiger beetles to ground beetles and whether/which of the many described subgenera of the genus Cicindela should be accorded generic status.  Erwin and Pearson fall solidly in the camp that consider tiger beetles a subgroup of ground beetles, a position that is becoming increasingly easy to defend on the basis of molecular phylogenetic analyses (e.g., Beutel et al. 2008).  Nontheless, I suspect many will be bothered by the decision to rank tiger beetles as a supertribe – “Cicindelitae” – in the subfamily Carabinae, rather than according the group subfamilial status.  Unfortunately, no justification for such placement is offered (unless this appears in Volume 1).  Likewise with subgenera, Erwin and Pearson break ranks with the preponderance of recent North American literature (including Pearson’s own 2006 book) and accord full genus status to most of the former subgenera of the genus Cicindela, including such familiar North American taxa as Cylindera, Dromochorus, Ellipsoptera, Eunota, and Habroscelimorpha.  Tribonia, on the other hand, is synonymized under Cicindela, leaving Cicindelidia as the only non-nominate subgenus of Cicindela.  Certain of these taxonomic acts will likely confront little opposition (e.g., Dromochorus as a full genus); however, again no justifications are provided, leaving the reader with the impression – rightly or wrongly – that the new rankings are the result of personal preference rather than new anaylsis.  I was also a bit puzzled by the inclusion of some subspecies as valid that Pearson himself had previously synonymized (e.g., Cicindela tranquebarica roguensis and C. tranquebarica lassenica).

The publisher, Pensoft, has established a reputation for quality with their previous offerings, and this book appears to continue that tradition. However, at a price of EURO 95, this book will probably not be highly sought after by the casual North American tiger beetle collector.  Nevertheless, I think any serious student of the group will want this in their library, regardless of how complete their literature collection on the group is.

I thank Terry Erwin for allowing me to use his gorgeous extended focus image of Sumlinia hirsutifrons (Sumlin), which graces the cover of this beautifully produced book.

REFERENCES:

Acorn, J.  2001.  Tiger Beetles of Alberta: Killers on the Clay, Stalkers on the Sand.  The University of Alberta Press, Edmonton, xix + 120 pp.

Beutela, R. G., I. Riberab and O. R. P. Bininda-Emonds. 2008. A genus-level supertree of Adephaga (Coleoptera). Organisms, Diversity & Evolution, 7:255–269.

Choate, P. M., Jr. 2003. A Field Guide and Identification Manual for Florida and Eastern U.S. Tiger Beetles.  University Press of Florida, Gainesville, 224 pp.

Erwin, T. L. and D. L. Pearson. 2008. A Treatise on the Western Hemisphere Caraboidea (Coleoptera). Their classification, distributions, and ways of life. Volume II (Carabidae-Nebriiformes 2-Cicindelitae). Pensoft Series Faunistica 84. Pensoft Publishers, Sofia, 400 pp.

Knisley, C. B. and T. D. Schultz.  1997.  The Biology of Tiger Beetles and a Guide to the Species of the South Atlantic States. Virginia Museum of Natural History, Martinsville, 210 pp.

Leonard, J. G. and R. T. Bell.  1998.  Northeastern Tiger Beetles: A Field Guide to Tiger Beetles of New England and Eastern Canada.  CRC Press, Boca Raton, 176 pp.

MacRae, T. C., and C. R. Brown. 2001. Missouri Tigers. The Missouri Conservationist 62(6):14–19.

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

Pearson, D. L. and A. P. Vogler.  2001.  Tiger Beetles: The Evolution, Ecology, and Diversity of the Cicindelids.  Cornell University Press, Ithaca, New York, 333 pp.

Copyright © Ted C. MacRae 2009

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Third time’s a charm!

/ Ted C. MacRae / 9 Comments

This post may seem like déjà vu to some of you, as it is my third featuring our common woodland tiger beetle species, Cicindela sexguttata (six-spotted tiger beetle). However, this post is as much a photography lesson as it is insect post, and when I say photography lesson I mean for myself – I’m not yet anywhere near the point where I feel qualified to dole out photography advice to others.

The last weekend of May, I returned to nearby Shaw Nature Reserve in hopes of photographing Cicindela unipunctata (one-spotted tiger beetle). This large, nearly flightless species has been recorded broadly across the eastern U.S. but is not encountered all that commonly. It is among the few species that seem to prefer more shaded woodland habitats (Pearson et al. 2006); however, its ecology is still not well understood. I had hoped to find it during my first outing with the new camera setup, but it was not to be and I had to settle for C. sexguttata as the first tiger beetle subject for my camera’s maiden voyage.   On this return visit, I arrived at the preserve shortly before noon and proceeded to walk back and forth along the trails where my colleague, Chris Brown, had noted healthy populations last year and one individual just three weeks ago.  For four hours, I gazed intently at the path in front of me in hopes of seeing the beetle – usually blending well with the ground because of its dull brown upper surface and noticed only because of its clumsy manner of running when disturbed.  All to no avail.  Of course, our old friend C. sexguttata was still present in good numbers, and since I wasn’t completely happy with the results of my first photo shoot of this species with the new camera I decided to try it again.

My main criticism of the initial photographs of this species was the harshness of the lighting.  I suspected that diffusers of some type would give a better result, so for this outing I covered the flash heads with small plastic diffuser caps that I had purchased with the flash unit.  The following series of photographs compare the results with and without the diffuser caps.  The photos have been left unenhanced but are reduced from their original size to 1200×800 pixels.  All of the photographs were taken using a Canon EF 100mm macro lens on a Canon EOS 50D, ISO 100, exposure 1/250 sec, and MT-24EX twin flash unit.  Click on the photos to see the enlarged version after reading the discussion of each.

Flash 1/4 power without diffuser caps, f/20

Flash 1/4 power without diffuser caps, f/20

This first photo is from the first session, during which I ran the flash unit at 1/4 power without diffuser caps.  The conditions were rather bright, and it required a relatively high f-stop (f/20) to get the exposure right.  This resulted in very good depth of field, but as you can see the lighting is rather harsh with bright highlights due to the brilliant, metallic coloration of the beetle.

1/8 power flash w/ diffuser caps

Flash 1/8 power flash with diffuser caps, f/10

In this photograph, I reduced the flash power to 1/8 and used the diffuser caps.  This softened the light considerably and removed much of the harsh highlighting.  However, I had to open up the aperature to f/10 in order to get good exposure, and as a result the depth of field really suffered.  Apparently the diffuser caps also reduce the amount of light from the flash, which combined with reducing the power to 1/8 substantially lowered the light levels.

Flash 1/4 power, w/ diffuser caps, f/13

Flash 1/4 power with diffuser caps, f/13

I then increased the flash back up to 1/4 power but kept the diffuser caps in place.  This allowed me to increase the f-stop to f/13, which resulted in much better depth of field.  Since this photograph was taken in fairly bright conditions, this suggests that I might want to go up to 1/2 power flash in lower light situations if I want to maintain a higher f-stop.  I am very happy with this photograph – the lighting is even with no harshness, and virtually the entire beetle from foreground to background is in focus.  A little post-processing might still be helpful for reducing the shadows a bit, but otherwise I think this is a pretty good standard to shoot for with my future tiger beetle photographs.

Photo details: Canon EF 100mm macro lens on a Canon EOS 50D, ISO 100, 1/250 sec, f/13, MT-24EX flash 1/8 power with diffuser caps

Cicindela unipunctata - flash 1/8 power with diffuser caps, f/13

As the saying goes, patience rewards those who wait, and a short time before I needed to leave, I finally saw the first C. unipunctata.  I was lucky enough to see it on the path without first disturbing it and was able to slowly crouch down into position and roll off a series of photos from this angle.  The photo I share here seemed to be the best of the series, but as I tried to shift to get a different view the little bugger began to bolt.  I blocked his escape with my hands until he seemed to settle down and then looked for him in the viewfinder, but I couldn’t find him – he had bolted as soon as I took my eye off of him, never to be seen again.  It amazes me how a relatively large beetle such as this – flightless even – can disappear completely amongst the vegetation.  Nevertheless, I accomplished my goal of getting at least one good photograph of this species, and you can be sure that I’ll be back to try for more.

I know there are several quite capable insect macrophotographers out there that occasionally read this blog – I encourage any comments or feedback that you might have on the techniques I have discussed here.

Copyright © Ted C. MacRae 2009

REFERENCE:

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

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On the road again!

/ Ted C. MacRae / 13 Comments

 

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By the time you read this, I’ll be on the road again for yet another extended bug collecting trip.  I don’t think I am ever happier than when I am on one of these trips – whether it be a once-in-a-lifetime visit to Africa or a one-week jaunt to the nearby plains.  With so many places to see – each with their own unique story – I don’t understand how anyone ever ends up getting bored.  The main destination for this trip is the Nature Conservancy’s recently established Four Canyon Preserve in northwestern Oklahoma.  This nearly 4,000-acre preserve contains a stunning assemblage of rugged, mixedgrass prairie ridges dissected by deep, chinquapin oak-lined canyons that drain into the Canadian River in southern Ellis County.  Although past grazing and fire suppression have reduced shrub cover, lowered vegetation complexity and promoted expansion of eastern redcedar (Juniperus virginiana) throughout the area, the preserve nevertheless supports a number of species of conservation concern such as Cassin’s sparrow, Swainson’s hawk, least tern, and Arkansas River shiner.

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As is typical with many protected areas, studies of the biotic diversity of this preserve have dealt primarily with its flora (Hoagland and Buthod 2007) and avifauna (Patten et al. 2006). Arthropods and other microfauna, on the other hand, remain essentially unknown.  I’ll be joining a group of entomologists – primarily hymenopterists – who began conducting surveys of the preserve’s insect fauna last fall.  While my colleagues gaze at the hyperdiversity of asteraceous flowers looking for things with stings, I’ll be staring at the red Permian sandstone and shale exposures – watching for any darting movement between clumps of grama and little bluestem that might indicate the presence of the enigmatic Cicindela celeripes (swift tiger beetle).  I’ve written previously about the occurrence of this rare, flightless tiger beetle in the Loess Hills of Iowa and our ongoing search for this species in northwestern Missouri in my post The Hunt for Cicindela celeripes.  Although this beetle has not yet been recorded at the preserve, it was seen very recently in nearby Alabaster Caverns – some 60 miles to the north, and a historical record is known from just south of the preserve.  My optimism is bolstered by the fact that the Alabaster Caverns individual was observed in late May – much earlier than the typical late June and early July records for this species further north in its stronghold in the Flint Hills of Kansas.  Of course, I will be looking for other things as well – other species of tiger beetles are likely to occur on the reddish loamy upland soils and quaternary alluvial deposits along the Canadian River, and any number of woodboring beetle species are likely to be found on herbaceous flowers and dead branches of the 51 species of woody plants recorded in the preserve.

After getting our fill of Four Canyon Preserve, we’ll visit the world’s largest remaining tract of tallgrass prairie, Tallgrass Prairie Preserve in northeastern Oklahoma.  Encompassing nearly 40,000 acres, we can do nothing more than only scratch its surface.  However, the tallgrass prairie habitat should provide a nice contrast to the mixedgrass prairie of Four Canyon Preserve, and it will be interesting to compare and contrast these two distinctive plant communities and their associated insect faunas.  After a week on the road¹, I’ll return to St. Louis for a brief respite before beginning a hectic four-week survey in northwestern Missouri for – you guessed it – Cicindela celeripes!

¹ I’ll be without internet access, so please forgive my nonresponsiveness to comments. I do have a couple of posts scheduled to appear during my absence.

My thanks to Mike Arduser, an expert hymenopterist and also a good friend, for bringing Four Canyon Preserve to my attention.  His spectacular photographs that I share here were all I needed to convince me to join him on his return trip this season.

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

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A new look at an old friend

/ Ted C. MacRae / 9 Comments

Chris Wirth just wrote a nice post summarizing the use of digital SLR camera systems for insect macrophotography.  Having just gone through the process of upgrading to a dSLR system from a point-and-shoot myself, I can relate to much of what he discusses.  The advantages are clear – higher image quality, far greater magnification capabilities, and control over lighting, shutter speed, aperture, etc.  He also discusses the disadvantages – chiefly co$t, weight, and initial learning curve.  He ends with this recommendation:

…if you are serious about insect photography and have the monetary resources, a DSLR is your only choice. Again, as of yet, nothing else provides similar quality or control.

Although I dabbled in insect photography many years ago with an Olympus OM-10 SLR film camera and a Zeiko 50mm macro lens, it wasn’t until I started this blog 18 months ago that I started making a real effort to photograph insects, using a Panasonic Lumix DMC-FX3 point-and-shoot that my dad had given to me for my birthday earlier that year. At first, I was amazed at the macro capabilities of this little camera – point, autofocus, and shoot! Yes, the photo needed to be cropped, and the reliance on natural light was not only limiting but often resulted in deep shadows – but nothing a little Photoshop couldn’t fix! It wasn’t long, however, before I began to see the limitations – not just on size, with tiger beetles being near the lower end of the size of subject I could photograph, but also with the quality of the images themselves. The perfectionist in me started envisioning what I could do if only I had the equipment. Mind you, I’m proud of the photographs I’ve acquired over the past months, given what I had to work with. But now that I have the equipment to do it right, I see a conflict on the horizon – do I attempt to go back and re-photograph all of those species that I’ve already photographed, or do I move on and and not look back? Perhaps a little of both is the best approach.

Cicindela sexguttataIn the meantime, I’ve got to learn how to use this camera. The first weekend I had it, I accompanied my friend and colleague, Chris Brown, to nearby Shaw Nature Reserve, where Chris had previously noted good populations of the very uncommon Cicindela unipunctata (one-spotted tiger beetle) [now Cylindera unipunctata, fide Erwin & Pearson 2008 – more on this in a future post] – what a fantastic species for my first photo shoot with the new setup. Unfortunately, we did not find this species (although I will eventually). Instead, I focused on the very prolific population of Cicindela sexguttata (six-spotted tiger beetle) that we found at this site. Cicindela sexguttata is the one tiger beetle that is, more than any other North American species, known by entomologists and non-entomologists alike. Cicindela sexguttataAnyone who has ever taken a walk in the eastern forests during spring has encountered this beetle – flashing brilliant green in the dappled sunlight, always a few yards ahead on the path. While belonging to the “spring/fall” group of species, adults of this species break ranks and stay put in their burrows during fall while other spring/fall species come out and explore for a bit before digging back in for the winter (Pearson et al. 2006). While many individuals do show the six white spots on the elytra that give the species its common name, this character is actually quite variable, with some northern populations completely lacking spots.

Cicindela sexguttataAs tiger beetles go, it’s one of the more difficult to photograph because of its shiny, metallic coloration (as opposed to the flat, dull coloration of Cyl. unipunctata). This was probably a good thing in terms of starting the learning process. I limited myself during this session to the 100mm macro lens (leaving the 1-5x beast for another day), with the photographs shown here being some of the better ones. While I like them, I also see a few things I did wrong. First was the flash – I set the flash units to 1/4 power and didn’t use any kind of diffusers, and as a result the lighting turned out harsh – especially for this brilliantly-colored, metallic species. Cicindela sexguttata I’ve softened the highlights a little bit in Photoshop, but the results are still not as good as if I had used a lower power and diffused the light, and ultimately my goal is to achieve well lit photographs that do not need post-processing to make them look right. Other than that, the day was mostly about getting used to handling the camera and learning how to judge f-stop based on my manual settings for exposure (1/200 sec) and ISO (100). The single individuals (above) were taken in full sunlight, and in that situation my f-stops tended to be too low (resulting in overexposure), while the mating pair was in shade where my f-stops tended too high (underexposed). Next time, I’ll try the diffusers I bought, use less flash power, and do more f-stop bracketing until I get a good feel for what I need in a given situation.

For comparison, here is the one C. sexguttata photograph I took with the point-and-shoot last year. This is about as good a photograph as I could get of this species using that camera. Besides being heavily cropped, it differs by being not very well exposed (despite post brightening), showing heavy shadows (despite post lightening), and lacking detail.
Cicindela sexguttata

REFERENCES:

Erwin, T. L. and D. L. Pearson. 2008. A treatise on the Western Hemisphere Caraboidea (Coleoptera). Their classification, distributions, and ways of life. Volume II (Carabidae-Nebriiformes 2-Cicindelitae). Pensoft Series Faunistica 84. Pensoft Publishers, Sofia, 400 pp. + 33 color plates.

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

Copyright © Ted C. MacRae 2009

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Tiger Beetle Rearing

/ Ted C. MacRae / 35 Comments

I recently found an interesting website called Tiger Beetle Rearing.  This website by doctoral candidate Rodger Gwiazdowski in the Joseph S. Elkinton lab, University of Massachusetts, Amherst contains a wealth of information and photographs covering equipment, techniques, and methods for rearing tiger beetles from egg to adult, with a primary focus on rearing endangered and threatened species of tiger beetles for conservation and re-release into the wild.  The lab has reared a number of tiger beetle species but is particularly interested in the Puritan tiger beetle (Cicindela puritana), threatened in the northeastern U.S.  After the first year of rearing, 90 2nd and 3rd instar C. puritana larvae were obtained and, as of the last update, were overwintering in individual tubes.  You’ll need to register with the site with a username and password to access the site, but this is accomplished quickly and easily.

Welcome to the Hotel Cicindela!

Welcome to the Hotel Cicindela!

I found this website of great interest as I begin my own efforts at rearing these beetles in the laboratory.  My primary interest is in rearing larvae that I collect in the field to adulthood – adults are much more easily identified than larvae (indeed, the larvae of many species remain undescribed), and rearing field-collected larvae is one way to get around the often limited temporal occurrence that many tiger beetle species exhibit as adults.  My operation isn’t nearly as sophisticated as the one developed in the Elkinton lab, but then I’m just a working stiff trying to do this (and a million other things) on the side. Despite this, I have had my first success, rearing to adulthood a larva I collected during the summer last year (see my post It’s a girl!).  In addition, I currently have a number of larvae collected last fall in Nebraska and South Dakota, which I put in terraria of native soil and kept in a cold incubator during the winter.  I pulled them out earlier this spring, and soon afterwards a number of larvae opened up their burrows and have been feasting on fall armyworm and corn earworm caterpillars every 2-3 days or so.  The larvae were collected from a variety of habitats and soil types, including sand, alkaline seeps, and red clay banks, so I’m hopeful that the ensuing adults will represent a variety of interesting species – perhaps some that I did not encounter in the field during that trip.

Cicindela_scutellaris_rearing_P1020931_2Beyond this, however, I am also interested in trying my hand at cross-breeding experiments – particularly with Missouri’s unique population of Cicindela scutellaris (festive tiger beetle).  I’ll need to wait until fall for this, however, since adults that are active in the field right now are sexually mature and have presumably already mated.  In the fall, a new generation of sexually-immature adults will emerge and feed for a time before burrowing back in for the winter and re-emerging the following spring ready to mate.  I would like to cross individuals from southeastern Missouri – representing an intergrade between the northern subspecies lecontei and the southern subspecies unicolor – with individuals from the northern part of the state that are clearly assignable to subspecies lecontei.  If possible, I would also like to obtain individuals from even further south that are clearly assignable to subspecies unicolor and cross them with both the southern and northern Missouri populations.  These crossing experiments may provide some insight into which of the subspecies the intergrade population is more closely related to, and it will be interesting to see how closely the progeny from the lecontei x unicolor cross resemble individuals from the intergrade population and the range of variation that they exhibit.  I should mention that Matt Brust (Chadron State College, Nebraska) has done a number of these inter-subspecific crosses with C. scutellaris, with some very interesting results among the progeny.

What I can do right now is work on techniques to make sure I can get females to lay eggs and then rear the larvae all the way through to adulthood.  For this, I brought back 9-10 live individuals from two localities of the intergrade population encountered on my recent trip to the southeastern lowlands.  Adults imbibing moisture from polymer gelI put equal numbers of males and females from each locality into separate terraria – each filled with native soil and a hydrophilic polymer gel made of anionic polyacrylamide. The beetles, who normally obtain moisture from their food or by “chewing” moist soil, chew instead on the gel. This eliminates the need to maintain a water dish or cotton batting that must be changed daily in order to prevent the growth of mold and bacteria. A few of the adults in each terrarium died shortly afterwards, possibly a result of stress or dehydration during transport (the photo right shows how eagerly they imbibed moisture from the polymer gel after being placed in the terrarium), but the remainder have lived for four weeks now and have been digging burrows and feeding whenever food is offered.  According to Matt Brust, C. scutellaris does not lay eggs on the surface of the soil (as does C. celeripes), but rather lays them about 1.5 to 2 inches below the surface.  It takes 2-3 weeks before the eggs start hatching, so I am expecting to see larval burrows appearing anytime now.  Matt tells me the key to getting eggs is to feed the adults “big-time” – thus, I have been offering fat, juicy fall armyworm or corn earworm larvae to the adults whenever they are out of their burrows.  Watch this entertaining video of one adult having lunch:

Copyright © Ted C. MacRae 2009

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