Now, some of you may think that because I serve as Layout Editor for the journal that I can horn in and put one of my own photographs on the cover whenever I want. This is not the case, and it was only because Managing Editor Ron Huber asked me if I had anything for the issue that I supplied the photo after having just done so for the previous issue. In actuality, we encourage others to submit their tiger beetle photographs for consideration, and since a majority of U.S. species have already been featured at some point over the years we especially encourage ex-U.S. photographers to submit their photos so that we can limit repetition. Obviously, C. floridana has never been featured on the cover before now, so it was a no-brainer choice for this issue.

The issue contains two delightful papers. The first is another by Mathew Brust on the stunningly gorgeous Cicindela pulchra that discusses not only additional northern range extensions in South Dakota and Wyoming, but also the rediscovery of the species in Nebraska far from the single previously known collection record in the state nearly 100 years ago! It is amazing to me that one of North America’s most conspicuously beautiful tiger beetle species has gone undetected for so long in such a large part of its range. The second paper by Dave Brzoska and Ron Huber is a long overdue biography of tiger beetle icon Norman Rumpp, who in his professional life was a rocket scientist (literally!) and as an avocation became one of North America’s leading authorities on tiger beetles (I am proud to claim ownership of Rumpp’s nearly complete set of The Coleopterists Bulletin). In addition to numerous publications and unpublished reports on tiger beetles in the western U.S., Rumpp described 12 species and subspecies of tiger beetles—including three of the western sand dune endemics that I have featured in recent weeks (Cicindela scutellaris yampae, C. arenicola, and C. albissima). What may not be appreciated is Rumpp’s sense of humor—well, just read the paper and see!

Copyright © Ted C. MacRae 2012

Nine days, ten states, 4,300 miles:
My peripatetic quest for North America’s rarest tiger beetles

The photographs used in the presentation have been seen in various posts here over the past few months, but I thought some may appreciate the chance to see them all together in presentation format. A PDF version of the original Powerpoint presentation can be downloaded by clicking on the link above (although with a file size of just over 18 MB a high-speed internet connection is recommended). My thanks to David Pearson, Professor of Biology at Arizona State University, for permission to include in the posted version scanned images and distribution maps from his supremely useful A Field Guide to the Tiger Beetles of the United States and Canada (the bible of North American cicindelophiles¹).

¹ If you have not yet bought this most excellent book, paperback versions can be bought new for as little as $41.74. Buy it and you’ll never fail another BitB tiger beetle ID Challenge!

If you download the presentation, please remember that all materials are copyright Ted C. MacRae unless attributed otherwise and may not be used without permission (personal use excepted) .

Copyright © Ted C. MacRae

Sandstone glade | nr. Calico Rock, Arkansas.

Although western sand dune endemics were the top goals on my cicindelophilic wish list during last fall’s Annual Tiger Beetle Trip, I started the trip by leaving St. Louis in the most unlikeliest of directions—south! No, I wasn’t trying to get to Denver without having to drive the tedious stretch of I-70 through Kansas. Rather, I wanted to take advantage of the chance to witness active adults of the Missouri/Arkansas disjunct population of Cicindelidia obsoleta vulturina (prairie tiger beetle)—perhaps my favorite of all tiger beetle species—on the sandstone glades near Calico Rock in north-central Arkansas. Widely disjunct from the main population’s eastern limit of distribution in central Texas, I’ve seen them at many locations in the White River Hills of southwestern Missouri and adjacent Arkansas over the past ten years, but never in the area around Calico Rock where they are best known from the state. I already had precise localities where I knew I could see them, as I had found 3rd-instar larvae earlier in the year (some of which had already emerged as adults), so I wanted see them and document the range of variability exhibited by adults at this southeasternmost known extent of the disjunct population’s distribution.

Cicindelidia obsoleta vulturina | nr. Calico Rock, Arkansas.

Although the adults were not quite as numerous as I have found them at certain sites in Missouri, I had no trouble finding them once I got to the area where I had collected the larvae this past June. While showing Steve Spomer our Missouri population last year, he commented that our Missouri adults seemed much less flighty than adults he had seen at Calico Rock. I must say that I agree with him, as I found the adults much more difficult to photograph than those in Missouri. To be honest, I had to stalk nearly ten individuals before the male in the photo above finally allowed me to get close to him. When adults are numerous this is not a problem, but in this case every failed attempt required several more minutes of searching for the next subject. Eventually, however, I got my mojo and started having success with the photographs.

Unlike true spring-fall species, mating occurs in fall instead of spring.

In the main population, and like other members of the genus Cicindelidia, adults are active during the summer months and exhibit the classic “summer” species life history. The Missouri/Arkansas disjunct population, however, shows a phenologic shift in adult activity to the cooler fall months—perhaps in response to the generally droughty conditions that prevail during the summer in this part of the country followed by rains during late summer and into fall. (This is one reason why I think this population may be deserving of separate subspecific status.) In this regard they appear to be ”spring-fall” species, but their life history does not match true members of that group, which emerge during fall as sexually immature adults, hibernate during winter, and re-emerge during spring for mating and oviposition. Thus, one never sees adults of classic spring-fall species like Cicindela limbalis mating during the fall. In contrast, adults of this disjunct population emerge, mate, and lay eggs all during the fall before the onset of winter, then they’re done. The eggs hatch during fall and require another season or two to reach 3rd-instar and pupate during the summer for fall emergence.

Coloration likely functions in crypsis, as shown by this individual nestled in amongst moss and lichens.

When viewed as prepared specimens in a cabinet, C. obsoleta and its subspecies are among the most conspicuous of species due to their large size (in Missouri and Arkansas only Tetracha virginica is larger), olive green coloration, and bold white maculations. More than likely, however, the combination of color and markings serve a crypsis function in their native habitat. This is clearly evident with the individual in the above photograph, who had retreated to a moss- and lichen-covered rock crevice in his efforts to evade my lens. Squint your eyes a little bit, and he almost disappears! It must be similar for visually based predators such as birds and lizards.

On more open ground and from a lower angle, the beetle is much more visible.

This same individual, however, becomes quite visible when chased onto more open rock surfaces (and viewed more laterally than from above). It is common to see individuals out in the open such as this, but more often than not when alarmed they fly or run to less exposed areas, relying on their cryptic coloration to avoid detection. In fact, when I follow beetles that have evaded me to the spot where I am sure they must have landed, I often fail to see them even though I am looking almost exactly in the area where they are sitting until they start to crawl and their movement catches my attention.

A rather greenish individual tries to hide amongst lichens and shortleaf pine duff.

I have observed a great deal of variability in coloration and maculation at locations in Missouri, with individuals ranging from bright green to dull olive-green to dark green and even brown, and the markings ranging from complete to interrupted. I saw a similar amount of variability in the Calico Rock population, with the exception of brownish (which I have only seen at the northernmost localities in Missouri) and fully maculated individuals. Most of the Calico Rock individuals were dull olive-green, but the female in the above photo (trying to evade my attentions by hiding amongst lichens and pine duff) was as bright a green as I’ve seen in any individual.

A very weakly maculate individual.

As mentioned above, I didn’t seen any individuals that I would consider fully maculated, and several that I saw were more weakly maculated than any I’ve seen in Missouri. The female in the photograph above was the most weakly-marked individual that I saw, with the lateral and median bands greatly interruped—the latter nearly reduced to small discal spots.

A dark, almost blackish female.

While I did not see brownish individuals as I have seen at the northernmost localities in Missouri, I did see the occasional blackish individual—the one in the above photograph also exhibiting about the greatest degree of macular development that I observed among the adults seen. My impression now is that there are clinal patterns to the coloration and macular development in this disjunct population, with markings tending to be more developed in northern localities. With the specimens collected from this and the many other locations throughout the disjunct population’s range that I have now sampled, a more critical assessment of variability in this population may now be possible.

Beetle's-eye view of sandstone glade habitat.

It has become standard practice for me to photograph tiger beetle habitats whenever I can. However, I’ve become interested recently in trying to understand how tiger beetles perceive their own habitats. While this isn’t possible to know precisely, ground level photographs can provide at least a clue into seeing the world from a beetle’s eye. I almost find this perspective of the glade habitat more interesting than the human perspective shown in the first photograph.

The last sight that their prey sees.

There can be little doubt about what the beetles themselves look like from the perspective of their prey. The photograph above may not properly represent the image generated by an insect’s collective ommatidia, but it certainly must be just as frightening!

Copyright © Ted C. MacRae 2012

Figure 1. Set-up shot with Exema sp. and caterpillar frass

If you had trouble finding the beetle in the above image then check out the next image and you’ll see the beetle has “sprouted” a head, legs, and antennae.

Figure 2. Set-up shot with Exema sp. and caterpillar frass

I don’t know what caught my eye the first time I encountered a warty leaf beetle on the foliage of a small shingle oak while exploring a woodland edge in Perry Co., MO.  It probably helped that it was one of the larger species of the genus Neochlamisus but it still only measured about 3-4 mm.  One thing I do remember about the encounter, though, is that there was something about it that made me do a double take.  My first thought was exactly what the beetle might have hoped, that it was caterpillar frass.  But this frass had legs (Figs. 3 and 4)!  I was at first incredulous but soon became enthralled as I beheld something that I had never noted while flipping through field guides.  I had once again stumbled across something that I would never have imagined—a beetle that mimics caterpillar poop!

Figure 3. Neochlamisus sp. on shingle oak

Figure 4. Neochlamisus from the perspective of a short distance away

The beetles in the tribe Chlamasini were apparently not at the table the day decisions were made on what model they would mimic.  These guys at best mimic small bits of debris but are dead ringers for the frass of lepidopteran larvae (i.e., caterpillars).  Then as if to add insult to injury, we dubbed the tribe the warty leaf beetles!  The Chlamasini may humbly mimic excreta but what they lack in a flashy model they make up for with absolutely superb mimicry.  The Chlamasini are remarkably similar to the frass of lepidopteran larvae in size, shape, texture, and color but the aspect that really completes the mimicry is that, upon disturbance, the head is retracted and the legs and antennae are neatly folded into precisely matched grooves leaving no indication that this was once a beetle (Figs. 5 and 6).  Even the finer details of coloration were not overlooked as some warty leaf beetle species are variably colored, including an almost metallic sheen in some places that closely resembles the coloration of some caterpillar frass.  In fact the mimicry of warty leaf beetles is so convincing that I recently dropped a piece of suspect frass in a vial in hopes that it might sprout legs and represent a new species of warty leaf beetle for me.

Figure 5. Exema sp. with appendages extended

Figure 6. Exema sp. with appendages retracted

If the disturbance is sufficient to cause the beetle to completely retract these appendages, they will likely roll off the leaf and fall out of harms way.  Though these beetles can be relatively common, occurring even in my suburban St. Louis yard, the small size [Exema is only 2-3 mm (Figs. 7 and 8) while Neochlamisus is slightly larger at 3-4 mm] and resemblance to something unremarkable ensures that these beetles often times go unnoticed.  When I have happened to notice these beetles I found Neochlamisus associated with shingle oak, Quercus imbricaria, and Exema associated with Asteraceae, including gray-headed coneflower, Ratibida pinnata, and sweet coneflower, Rudbeckia subtomentosa.

Figure 7. Exema sp. on sweet coneflower, Rudbeckia subtomentosa

Figure 8. Exema sp. ready for flight

The Chlamasini are in the subfamily Cryptocephalinae within the leaf beetle family (Chrysomelidae).  The Chlamisini can be found worldwide but are most diverse in the Neotropics.   We have 6 genera in North America, two of which are shown here.  Interestingly, the excreta theme doesn’t stop at frass-mimicry.  Like other members of Crytocephalinae, warty leaf beetle larvae are “case-bearing”; that is they are housed in a case which in this instance is made out of… you guessed it, their own feces (Fig. 9).  You would think that most moms would frown on such a practices but mothers in the Cryptocephalinae actually instigate the practice when they equip each egg laid with a cap of feces that serves as starting material for the case and likely also serves to dissuade would be predators.

Figure 9. Chlamasini larva, likely that of Exema sp. on sweet coneflower, Rudbeckia subtomentosa

My experiences with Neoclamisus seven years ago captures perfectly why I am so drawn to explore for insects— there is always something new to find and every once in a while something comes out of the wood work that is beyond what I could have imagined.

REFERENCE:

Lourdes Chamorro-Lacayo, M. & A. Konstantinov. 2009. Synopsis of warty leaf beetle genera of the world (Coleoptera, Chrysomelidae, Cryptocephalinae, Chlamisini). ZooKeys 8:63–88.

Copyright © Chris Brown 2012

Photographing Cicindela pulchra in South Dakota.

I first met Chris when he came to my lab as a summer intern more than a decade ago (not long after I myself had taken my position here). It didn’t take long before Chris’ interest in joining me on my field exploits became apparent, and I was happy to have his company. During those early trips, I was immediately impressed not only by his skill as a photographer, but also his interest in understanding broader ecological context (too many young collectors want to know only the bug’s name and where they can find it). The Missouri tiger beetle project was in its earliest stages at that time—I thought his photographic capabilities would compliment my field experience in surveying for these insects and invited him to join me in the effort. In the years since, we have traveled together to all corners of Missouri, made two trips to the neighboring Great Plains, and explored the length of the Rio Grande River from Boca Chica to Big Bend. Chris’ travels, with me and separately, give him unique perspective and breadth of knowledge, and as much as he may claim to have learned from me during our joint travels, I have learned from him equally as much. Perhaps the most valuable lesson learned is to use photography as a means not to capture just images of insects, but moments in their natural history—features not easily appreciated when looking at preserved insect specimens in a cabinet. Please join me in welcoming Chris to BitB, and look for his first post to appear in the next day or so—I think you will find it a delightful read.

Chris surveys the loess hills landscape in northwestern Missouri

Copyright © Ted C. MacRae 2012