Almost every tiger beetle trip that I take has a mix of gimmes and stretch goals. That’s alright—it’s impossible to find everything every time out, and if I eschewed the common and was happy only when I found something truly rare, then I would probably find myself rather unsatisfied most of the time. For the stretch goals, however, “success” can mean many things—obviously the best case scenario is to find it in good enough numbers to allow responsible collection of an adequate series and photograph enough individuals in situ to ensure that at least a few shots will have the focus, lighting, and composition that I want. Success can also be something less than that—maybe I find only a few and don’t get a very good series, or I have trouble getting field shots and am not happy with the shots I got…or worse I don’t even get field shots! The least successful version of “success” is when I end up with just one single beetle, and the only photographs I get are very ordinary-looking shots of that one beetle in confinement. Like what happened with Cicindela decemnotata (Badlands Tiger Beetle).
Chris Brown and I knew this species would be a stretch goal when we added “Soda Lake, Wyoming” to the itinerary of our 7th Annual Fall Tiger Beetle Trip™ (location “H” on this map). Cicindela decemnotata is the westernmost representative (Rocky Mountains from the northwestern Great Plains and northern Great Basin north to Yukon) of a group of species that seem to be closely related and resemble each other in their green coloration varying degrees of red on the head, pronotum and elytra and their variably developed white elytral markings (Pearson et al. 2006). Cicindela limbalis, C. splendida and C. denverensis occur as a partially allopatric species complex further east in the Great Plains, while C. sexguttata, C. patruela and C. denikei occupy more forested regions even further to the east. On this trip we were focusing on Great Plains tiger beetles and the dune specialists of the Yampa River Valley of northwestern Colorado. Our drive from northwestern Nebraska to the Yampa Valley would skirt the eastern edge of C. decemnotata‘s distribution, so we decided to stop by Soda Lake where Matt Brust had seen the species in previous years.
It took most of the morning to reach the spot, so by the time we arrived we were anxious to get out and start searching the sage brush habitat. For me it was an unfamiliar landscape—at that time my northwesternmost push for tiger beetles yet, and like many western habitats it seemed vast and unending. We were optimistic, however, because it just “looked” like good tiger beetle habitat, with ribbons of alkaline flats weaving through open brush. Of course, as time passes and one starts to recognize that they are again searching ground already covered with no sign of beetles, optimism begins to wane and searches become more deliberate. We were there for almost an hour before I heard Chris call out. He had abandoned the alkaline flats—obvious habitat it would seem—and started looking upon some slightly sandier low ridges a little further to the south. I hustled to where he was standing, and we both looked at the beetle, calmly sitting on the sand, as we deliberated our next move. Should we try to photograph it? It seemed not at all skittish—but what if we failed, it got away, and then we never saw another one? We played it safe, netted it (easily), and placed it in a vial for transfer to a container of native soil should further efforts at finding and photographing the species fail. It was perhaps another 45 minutes before we saw another beetle—I don’t know if it was just a less cooperative individual or the heat of the day had kicked in, but as soon as I started my approach it was gone. We saw another not long after, but same story. Finally we saw one last beetle that seemed to tolerate my approach to the point that I even began looking for it in the view finder—at which point it promptly zipped away. This small prospect of success only served to prolong our vain searching before we eventually we accepted defeat and tried to be happy with the single individual that we had caught and the photographs that we would take of it in its artificial home.
Part of me really doesn’t like showing photographs of confined tiger beetles—not for any philosophical reasons, but because I just don’t like the way they look. Rarely do they exhibit the elegant stilting and other thermoregulatory behaviors that place them in much more pleasing postures when photographed in situ. Rather, they often have a “hunkered down” look that says “I’m not happy and I don’t want to be here, so I’m not going to smile for the camera!” Since these photos were taken, I have learned a few tricks to deal with confined beetles and achieve more aesthetically pleasing photographs—these include the use of much larger arenas, allowing the beetles more time to accommodate to their environs, and elevating the substrate relative to the camera (maybe a subject for a future post). In the end, however, they are still confined and can’t be passed off as anything but that.
As an aside, tiger beetle pros Barry Knisley, Ryan Woodcock and Mike Kippenhan have recently published the results of an impressive study of this species in which a combination of morphological and molecular evidence support the recognition of four subspecific entities—three described as new (Knisley et al. 2012). The molecular analyses not only support the subspecific distinctions postulated from morphology but also suggest that populations have undergone rapid phylogenetic radiation in the recent geological past. Much of the area occupied by C. decemnotata was covered by an ice shield during the most recent glaciations and, thus, has opened up for colonization only during the past 10,000 years (Pearson and Vogler 2001). The molecular analyses showed a relatively low amount of genetic divergence within C. decemnotata populations, which combined with marked morphological differences suggests recent and rapid radiation—most likely in the wake of glacial recession. A similar situation has been observed with members of the Cicindela maritima species-group, which occupy much the same range as C. decemnotata and, presumably, have experienced similar selection pressures in the recent geological past.
Knisley, C. B., M. R. Woodcock & M. G. Kippenhan. 2012. A morphological and mtDNA analysis of the badlands tiger beetle, Cicindela (s. str.) decemnotata Say, 1817 (Coleoptera: Carabidae: Cicindelinae) with the description of three new subspecies. Insecta Mundi 0214:1–49.
Pearson, D. L., C. B. Knisley & 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 2012