Swift Tiger Beetle: Species on the Brink

ResearchBlogging.orgIn July 2008, Chris Brown and I made a spur-of-the-moment trip to Hitchcock Preserve near Council Bluffs, Iowa, where only a week earlier Cylindera celeripes (Swift Tiger Beetle), one of North America’s most enigmatic tiger beetles, had just been discovered. Reportedly once common in the blufftop prairies of western Iowa and further west in eastern Nebraska and Kansas, this tiny (6–8 mm in length), flightless beetle has suffered severe population declines over the past 100 years. Only small numbers of individuals have been encountered outside of the type locality (Fort Riley, Kansas) in recent years, and in Nebraska the species is now considered extirpated (Spomer et al. 2008). Our reasons for going to Iowa had to do with our as yet unsuccessful effort to find the species in northwestern Missouri as part of our broader studies of the state’s tiger beetle fauna. Although it had never been recorded from Missouri, we felt there was some chance it might be found in the tiny loess hilltop prairie remnants still remaining in the state at the southern terminus of the Loess Hills landform. We reasoned our failure to find the species might be related to its very small size and rapid running capabilities (giving them more the appearance of small ants or spiders than tiger beetles), limited temporal occurrence, and tendency to hide amongst the bases of grass clumps (Pearson et al. 2006). If we could find the species at a locality where they were known to occur, perhaps an improved search image and better understanding of their precise microhabitat preferences would help us locate the species in Missouri.

Fig. 1. Cylindera celeripes (LeConte) adults at: a) Hitchcock Nature Center, Pottawattamie Co., Iowa (13.vii.2008); b) Alabaster Caverns State Park, Woodward Co., Oklahoma (10.vi.2009); c) same locality as “b”, note parasite (possibly Hymenoptera: Dryinidae) protruding from abdomen and ant head attached to right antenna; d) Brickyard Hill Natural Area, Atchison Co., Missouri (27.vi.2009). Photos by C.R.Brown (a) and T.C.MacRae (b-d).

We didn’t realize it at the time, but that trip marked the beginning of a two-year study that would not only see us succeed in finding C. celeripes in Iowa, but also discover new populations in Missouri and northwestern Oklahoma (Figs. 1a–d). With so much new information about the species and the long-standing concerns by many contemporary cicindelid workers about its status, it seemed appropriate to conduct a comprehensive review of the historical occurrence of this species to establish context for its contemporary occurrence and clarify implications for its long term protection and conservation. This was accomplished through compilation of label data from nearly 1,000 specimens residing in the collections of contemporary tiger beetle workers, all of the major public insect museums in the states of Iowa, Kansas, Missouri, Nebraska, Oklahoma, and Texas, and the collections at the U.S. National Museum and Florida State Collection of Arthropods. Collectively, this material is presumed to represent the bulk of material that exists for the species, representing nearly all localities recorded for the species and time periods in which it has been collected.

Label data confirmed the historical abundance of this species, especially in the vicinity of Manhattan and Fort Riley, Kansas; Lincoln and Omaha, Nebraska; and Council Bluffs, Iowa. Hundreds of specimens were routinely collected in the native grassland habitats around these areas during the late 1800s and early 1900s, their abundance documented by entomologists in both journal articles and private letters. One of the most interesting examples of the latter was by Nebraska collector F. H. Shoemaker, who wrote the following in a 1905 letter to R. H. Wolcott:

There is another trip, down the river to the big spring by the railroad track near Albright, then across the river (the heronry route) where we collect hirticollis, repanda, vulgaris [= tranquebarica], cuprascens, and – vat you call ‘im? – celeripes! I took 147 of the latter in an hour and a half Sunday, and the supply was undiminished.

Fig. 8. Historical and currently known geographical occurrence of Cylindera celeripes by county. Red = last record prior to 1920; orange = last record 1941–1960 (“?” = questionable record); green = last record 1991–1996; blue = last record 2005–2011.

Although the recent collections of C. celeripes from near Council Bluffs and through the years near Fort Riley show that the species has managed to persist in these areas, there is little question that it is far less abundant and widespread now than it was in the early 20th century (Fig. 8).  Not only are the areas in which present day populations are known to occur limited, but the numbers of individuals seen in them are very low. In Missouri, the species was listed immediately after its discovery in the state as a species of conservation concern with a status of S1 (= “critically imperiled”) due to the highly restricted occurrence of suitable habitat (loess hill prairie) in the state and small populations observed within them. The situation is even worse in Nebraska, where the species has not been seen for nearly 100 years despite dedicated searches by expert contemporary tiger beetle workers such as Matt Brust and Steve Spomer. Considering the near-complete elimination of suitable native grassland habitats by conversion to agriculture and degradation of the few existing remnants due to encroachment by woody vegetation and invasive exotics, the likelihood of finding extant populations of C. celeripes in Nebraska seems remote. Only in the Red Hills of northwestern Oklahoma does the species appear to be secure due to the extensiveness of suitable areas of habitat and robust numbers of individuals observed within them at the present time. An enigmatic record exists from Arkansas, based on a single individual collected near Calico Rock in 1996. This individual represents a significant extension of the known geographical range of the species, but repeated attempts to find the species at that locality during the past year were not successful.

The persistence of populations, albeit small, in multiple areas, along with the occurrence of robust populations in northwestern Oklahoma, makes it unlikely that C. celeripesqualifies for listing as a threatened or endangered species at the federal level. Nevertheless, the limited availability of suitable habitat in many areas and low population numbers found within them clearly suggest that conservation measures are warranted at the state level, especially in Iowa, Kansas and Missouri, to prevent its extirpation from these states. In these states, land management practices should be implemented at sites known to support populations of the beetle in an effort to maintain and expand the native grassland habitats upon which they rely. These include various disturbance factors such as mechanical removal of woody vegetation, judicious use of prescribed burning, and selective grazing (taking care to do so in a manner that minimizes impacts to beetle populations).


MacRae, T. C. and C. R. Brown. 2011. Historical and contemporary occurrence of Cylindera (s. str.) celeripes (LeConte) (Coleoptera: Carabidae: Cicindelinae) and implications for its conservation. The Coleopterists Bulletin 65(3):230–241 DOI: 10.1649/072.065.0304

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.

Spomer, S. M., M. L. Brust, D. C. Backlund and S. Weins.  2008. Tiger Beetles of South Dakota & Nebraska. University of Nebraska, Department of Entomology, Lincoln, 60 pp.

Copyright © Ted C. MacRae 2011

The hunt for Cicindela celeripes

One of the more enigmatic tiger beetle species in North America is Cicindela celeripes LeConte (swift tiger beetle). This small (6-8 mm), flightless species has been recorded from a restricted area of the eastern and southern Great Plains – from eastern Nebraska and westernmost Iowa south through Kansas to western Oklahoma and the Texas panhandle (Hoback and Riggins 2001, Pearson et al. 2006). Unfortunately, populations of this species appear to have suffered severe declines. It apparently is holding strong in the Flint Hills region of Kansas, but many of the records from outside of that area date back more than a century. Reportedly once common on the bluff prairies along the Missouri River, it has not been seen in Nebraska since 1915 and may have been extirpated from that state (Brust et al. 2005). The reasons for this decline undoubtedly involve loss of preferred habitat – upland prairies and grasslands with clay or loess soils and sparse or patchy vegetation. Areas supporting these native habitats have been drastically reduced since European settlement of the region, and suppression of fire – so vital to prairie ecosystems – has led to extensive woody encroachment on the few prairie relicts that do remain. Unlike many other tiger beetle species that have been able to adapt to these anthropogenic changes, this species apparently cannot survive in such altered habitats.

Chris Brown and I have been interested in this species ever since we began surveying the tiger beetles of Missouri. It has not yet been recorded from the state, but we have long suspected that it might occur in extreme northwest Missouri. It is here where the Loess Hill prairies along the Missouri River reach their southern terminus. (Incidentally, the Loess Hills are themselves a globally significant geological landform, possessing natural features rarely found elsewhere on earth. They will be the subject of a future post). We have searched several of what we consider to be the most promising potential sites for this species in Missouri, though without success. Nevertheless, we remain optimistic that the species might eventually be found in Missouri and has simply been overlooked due to the limited temporal occurrence, small size, rapid running capabilities, and tendency of adults to dart rapidly to the bases of grass clumps where they hide (Pearson et al. 2006). Furthermore, even though the species has not been seen recently in adjacent areas of Nebraska where it has been recorded in the past, it has been seen recently in a few Loess Hill prairie remnants just to the north in Iowa.

A few weeks ago, I was fortunate to receive specific locality information for one of the recently located Iowa populations. Armed with site descriptions, Google maps, photographs, and whatever book learnin’ I had gained about this species, my colleague and I made the long drive to southwestern Iowa in hopes of locating the population for ourselves, seeing adults in their native habitat, and using the learnings we would gain about their habitat preferences and field behavior to augment our efforts to eventually locate the species in northwestern Missouri. At mid-July, we were nearing the end of the adult activity period, but adults had been observed at the site the weekend prior, so we felt reasonably confident that adults might still be found. Additionally, fresh off of our recent success at locating the related Cicindela cursitans in Missouri (another small, flightless, fast-running species), we were hopeful that we now possessed the proper “search image” to recognize C. celeripes in the field should we have the good fortune to encounter it.

Walking into the area, I was impressed at the extensiveness of the prairie habitat – much larger than any of Missouri’s Loess Hill prairies. The presence of large, charred red-cedar cadavers on the lower slopes revealed active management for prairie restoration. We later learned from the area manager that the restoration area had been acquired from a neighboring landowner who had used the land for grazing and sold it when it became unproductive. I can only imagine the second thoughts that landowner must have had when subsequent burn regimes and woody growth removal prompted a return to the beautifully lush sea of prairie vegetation that now covered the hills. As we approached the area where we decided the beetles must have been seen, we started searching slowly and deliberately – looking carefully for any movement between the clumps of grass. It didn’t appear to be prime habitat for C. celeripes – the vegetation was just so thick, with only small openings among the plants. We continued to scour the area closely but saw nothing, and my optimism began to wane. Wrong spot? – I don’t think so. Bad search image? – hard to imagine, considering its similarity to C. cursitans. Too late? – could be.

After it became obvious we were searching the same gaps in the vegetation repeatedly, I started walking towards a small cut further down the hillside that I had noticed earlier (just visible in the previous photo). I had thought, “That’s tiger beetle land down there!” My optimism increased when I reached the cut, seeing the remains of an old, overgrown 2-track leading through the cut and on down the hillside. Vegetation was much sparser within and below the cut – it looked perfect. Chris had become distracted taking photographs of something, so I began searching. I’d been in the cut a few minutes when I thought I saw something flash across a bare patch out of the corner of my eye – was that it? It had to be. I carefully inspected around the base of every clump of vegetation at my feet but found nothing. It must have been wishful thinking – just another spider. I continued on down the cut, and within a few more minutes I saw the flash again – this time there was no doubt as to what it was, and I had a lock on it. I started slapping the ground frantically as the little guy darted erratically under, around, and over my hands. In the few seconds while this was happening, I was simultaneously exuberant at having succeeded in finding it, utterly astounded by its speed and evasiveness, and desperately afraid that it was getting away – swift tiger beetle, indeed! Persistence paid off, however, and eventually I had it firmly in my grasp.

We would see a total of seven individuals that day. Most of them were within or immediately below the cut, while another individual was seen much further down the 2-track. Mindful of the population declines this species has experienced, we decided to capture just three individuals (even though by this point in the season mating and oviposition would have been largely complete) in hopes that at least one would survive the trip back to the lab for photographs. Our primary goal – to see the species in its native habitat – had been accomplished. We now turned our attention to attempting in situ field photographs. This would prove to be too difficult a task – each beetle we located immediately ran for cover, and flushing it out only caused it to dart to another clump of vegetation. This scenario repeated with each beetle until eventually it simply vanished. We would have to settle for photographs of our captured specimens in a confined arena – a few of which are shown here. The beetles were photographed on a chunk of native loess taken from the site, and no chilling or other “calming” techniques were used. Spomer et al. (2008, Field Guide to the Tiger Beetles of Nebraska and South Dakota) state that C. celeripes is a delicate species that does not do well in captivity. It has never been reared, and the larva is unknown. Nevertheless, I placed the chunk of native loess in a plastic tupperware container and transplanted into one corner a small clump of bluegrass from my yard. The soil around the grass clump is kept moist, and every few days I have placed various small insects in the container. Of the three individuals that we brought back, two died within two days. The third individual (these photographs), however, has now survived for four weeks! Moreover, it is a female, and during the past two weeks six larval burrows have appeared in the soil (and another egg was seen on the soil surface just yesterday). Indeed, an egg can be seen in the upper right of the first photo. It remains to be seen whether I will be successful at rearing them to adulthood; however, I’m hopeful this can be accomplished using methods described for C. cursitans (Brust et al. 2005).

Do I still think C. celeripes occurs in Missouri? I don’t know – on one hand, the mixed grass Loess Hill prairie habitats in which the beetle lives in Iowa do extend south into Missouri, and the beetle could be inhabiting them but be easily overlooked for the reasons I’ve already mentioned. However, Missouri’s Loess Hill prairie relicts are small, both in number and in size, and highly disjunct. Such features increase the likelihood of localized extinctions and hamper recolonization through dispersal, especially in flightless species that must traverse unsuitable habitat. With its adult activity period winding down, renewed efforts to locate this species in Missouri will have to wait until next season. Hopefully, the knowledge we gained this season will help this become a reality. For now, the hunt continues…

(closing photo by C. Brown)