In North America, few beetles can rival jewel beetles in the family Buprestidae for sheer beauty, and within the family this beauty is perhaps best exemplified by species in the family’s namesake genus Buprestis. Often flashing yellow, green, coppery, or red, species in this genus combine brilliant colors, moderately large size, and relative rarity to make them desirable additions to the collections of casual and serious collectors alike.

Buprestis (Knulliobuprestis) confluenta | Woods Co., Oklahoma

Over the years I’ve had some success collecting certain species in this genus, but even after 30 years of collecting there still remain several species that have eluded my net. A few weeks ago I posted photos of and wrote about my experience collecting not one, but two of these species that had so far eluded me—B. striata and B. salisburyensis—both as single specimens from a single tree in the mountains of Tennessee. Three weeks after collecting these species, I began a collecting trip west into the heart of the Great Plains with the primary purpose of using recently developed lures to collect some uncommonly encountered prionid longhorned beetles. Before reaching the first locality, however, field mate Jeff Huether and I stopped off in Hardtner, Kansas to visit with fellow beetle enthusiast “Beetle Bill” Smith and do a little collecting with him before continuing on. Bill took us to a spot just south of the nearby state line into Oklahoma to a spot where he had collected, among other things, yet another of the Buprestis spp. that had so far eluded me—B. confluenta.

If B. striata and B. salisburyensis are beautiful, then B. confluenta is downright stunning! Brilliant green, perhaps with a slight coppery brown to purplish blue hue and with more or less confluent (thus the species name) fine yellow flecks densely scattered over the elytra, it is one of the easiest to identify of any species in the genus. Moreover, unlike the previous two species, I had already made several attempts to collect B. confluenta during several previous trips to the Great Plains, stopping wherever I saw a nice stand of the large eastern cottonwood trees (Populus deltoides) in which larvae of the species are known to develop. Frustratingly, as if to taunt me, I have even seen specimens on more than one occasion in one of the many 4H and student collections that I have examined over the years in Missouri and Kansas.

Today was different, however—I could just feel it. Pulling up to the spot, my attention was immediately drawn to a grove of large cottonwood trees, some dead with bark-less trunks still standing. I thought to myself, “Those look like Buprestis trees!” While Bill and Jeff swept nearby herbaceous plants looking for a blister beetle that Jeff was interested in, I picked my way through the cottonwood grove, carefully approaching each tree—especially the dead ones—and scanning the trunk for any sign of movement or flash of color. It took a long time—well over an hour, by which time I had almost given up hope and begun thinking that this would be yet another unsuccessful attempt to collect the species. Suddenly, there it was sitting on the trunk of a recently fallen tree in all of its unmistakable glory! I froze at first, afraid of spooking it by too excited an approach, then remembered that species of Buprestis in general are not very skittish or as quick to take flight as many other members of the family (e.g., species in the genus Chrysobothris). I resumed my approach, albeit still cautiously just in case, and easily secured the specimen in a vial. My season now included a Buprestis hat-trick! The beetle was not only calm but actually seemed disinclined to flee, prompting me to release it back onto the tree trunk for a few quick field photos before placing it back in the vial for better photos later in the security of my hotel room that evening.

Buprestis spp. love large, dead, bark-less cottonwood trunks.

Among North American jewel beetles, B. confluenta has one of the stranger geographic distributions, having been recorded from most of the central and western states and provinces as far east as Quebec and Indiana (Nelson et al. 2008). This is no doubt a consequence of the distribution of its primary larval hosts—cottonwood and quaking aspen (Populus tremuloides) (Burke 1917, Nicolay & Weiss 1918). In my Missouri checklist (MacRae 1991) I saw only two specimens from the state, both in counties along its western edge near Iowa and Kansas. Considering how abundant cottonwood is in Missouri, it is a mystery to me why this species should be so rare in the state. But then, I’ve not found it easy to come by in Kansas or Oklahoma either, where more records seem to exist than in any other state. Even on this occasion, when I would finally find the species after 30 years of searching, only this one, single specimen was seen. Interestingly, I would also collect about a half dozen specimens of the closely related species, B. rufipes (more commonly associated with oaks), off of the same trees that I searched so intensively for B. confluenta.

The requisite frontal portrait!

REFERENCES:

Burke, H. E. 1917. Flat-headed borers affecting forest trees in the United States. U.S. Department of Agriculture Bulletin 437, 9 pp. [Biodiversity Heritage Library].

MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri. Insecta Mundi 5(2):101–126 [pdf].

Nelson, G. H., G. C. Walters, Jr., R. D. Haines & C. L. Bellamy.  2008.  A Catalogue and Bibliography of the Buprestoidea of American North of Mexico.  Coleopterists Society Special Publication No. 4, The Coleopterists Society, North Potomac, Maryland, 274 pp. [description].

Nicolay, A. S. & H. B. Weiss. 1918. A review of the genus Buprestis in North America. Journal of the New York Entomological Society 26(2):75–109 [pdf].

© Ted C. MacRae 2014