In North America, beetles in the family Buprestidae are commonly referred to as ”metallic woodboring beetles.” This may be a perfectly adequate name—accurate and descriptive, but it’s also a bit dry and not terribly imaginative. Personally, I much prefer the moniker given to these beetles by the rest of the world—”jewel beetles!” No other name better captures the essence of these dazzling insects—brilliant, sparkling, even gaudy in coloration and with the most exquisite of surface sculptures, and no other group of buprestids better typifies jewel beetles at their most extreme than the great tribe Chrysochroini—the ‘‘classic’’ jewel beetles! Members of this tribe are found throughout the world (Chalcophora, Texania, Lampetis and Dicerca are the most familiar North American genera) but reach their zenith in the ancient rainforests of Africa and southeast Asia—big, beautiful beetles with screaming iridescence of green, red, yellow and blue. Living jewels!

I have a fair number of chalcophorines in my collection, and among the more recent acquisitions is this fine specimen of the species Madecassia rothschildi. One of a pair of specimens given to me by friend and world buprestid-expert Chuck Bellamy, this larger of the two measures a whopping 45 mm in length (that’s almost 2 inches, folks!), surely near the top end of the range for this genus and paling only against such giants as Euchroma and Megaloxantha. The reddish-brown eyes on a brilliant green head, turquoise legs and white-flecked, wine-colored elytra are enough to make it stand out, but it is the distinctive yellow-lime “false eyes” that made me do a double-take when I first laid eyes on them after opening the box. A closer look at the eye spots reveals the yellow-lime area to be densely pulverescent.

Madecassia rothschildi and the two other species placed in the genus all hail from Madagascar (Bellamy 2008). This particular species must be rather common despite the well-chronicled disappearance of Madagascar’s native forests, as a quick Google search of the species name (or its older synonym, Lampropepla rothschildi) brings up a multitude of web sites for commercial insect dealers with this species in stock. The combination of its size, coloration, and availability must make it a popular item among philatelic collectors, and although I’m not a big fan of buying insects, I can understand the desire to purchase something as spectacular as this.

I’ll be the first to admit that these photos aren’t nearly as striking as Gianfranco Merati‘s photos of Polybothris sumptuosa, but they do well illustrate the iridescence that is common to these beetles. Iridescent coloration is due not to pigments in the exoskeleton, but rather the physical properties of different layers in the insect cuticle that reflect light of specific wavelengths in different directions (hence, resulting in apparent color shifts depending on the angle at which the subject is viewed).

Despite its commonness, it seems that virtually nothing known about the life history of this species or the host plants that it utilizes. Records in Madagascar are all from the south (Bellamy 2006), but all other references to this species consist exclusively of catalogue listings. A large, conspicuous, abundant species such as this almost begs for ecological studies—the “eye spots” can be presumed to function in predator avoidance, but how? What is the purpose of the dense brush of hairs inside the labrum (upper lip) and next to the mandibles, and why is the labrum itself so acutely emarginated? Adults are largely reproducers, not feeders—do these structures serve some other function not related to feeding? What about the dense covering of “pits” over most of the body surfaces—presumably they contain chemoreceptors for smell, but what? Host plant volatiles? Mates? Humidity? So many questions, so few answers. Imagine the even greater paucity of knowledge that exists for its smaller, less conspicuous relatives that also make their homes in the forests of Madagascar (most of them probably not adapting as well to the man-induced changes of the past century).

Congratulations to Tim Eisele, whose 13 pts not only nets him the win in Super Crop Challenge #11 but also moves him up to 2nd place in the overall standings for BitB Challenge Session #5 with 29 pts. Mr. Phidippus‘s 12 pts  just missed the win but keep him in well in command atop the overall standings at 43 pts. Strong showings by Dorian Patkus (11 pts) and Dennis Haines and Roy (10 pts each) also keep them in the overall hunt with 20, 25 and 28 pts, respectively. I suspect the top spot is now a lock, but it looks like we’ve got a real battle brewing for the remaining podium spots. There will be at least one more challenge in the current challenge session, and for the first time I am considering consolation prizes to the final 2nd and 3rd podium spots as well, so everybody will want to make sure they participate in the next challenge.

REFERENCES:

Bellamy, C. L. 2006. Insecta Coleoptera Buprestidae de Madagascar et des îles voisines. Catalogue annoté. Faune de Madagascar 92:1–267.

Bellamy, C. L.  2008. World catalogue and bibliography of the jewel beetles (Coleoptera: Buprestoidea),  Volume 1: Introduction: fossil taxa; Schizopodinae; Buprestidae: Julodinae—Chrysochroinae: Poecilonotini.  Pensoft Series Faunistica 76: 1-625.

Copyright © Ted C. MacRae 2012

Copyright © Ted C. MacRae 2012

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