This is the best known of the American species of Poecilonota, and the one most commonly collected east of the Rocky Mountain.—Evans (1957)
I’ve been interested in insects since I was a kid, but I didn’t really become a dedicated coleopterist until after I’d finished graduate school and started working as a field entomologist with the Missouri Department of Agriculture. It was a perfect job for a young entomologist with a bent for collecting—being outside all day inspecting nursery stock and driving the back roads checking insect traps. It wasn’t long before I found myself focusing on wood-boring beetles, due initially to their horticultural importance but eventually to their astounding diversity and intrinsic beauty. So began my formal survey of the families Buprestidae and Cerambycidae in Missouri, and I spent the next eight years collecting them in all corners of the state and examining every insect collection, public and private, that I could find that might contain Missouri representatives of these families. In the end, I documented a cool 350 species and subspecies in the two families combined, more than a fifth of which represented new state records (MacRae 1991, 1994).
One species, however, that I had expected to find almost completely eluded me. This, despite the quote above by Evans (1957) in his revision of the genus Poecilonota in North America. Although it had been recorded from much of North America east of the Rocky Mountains in association with poplars (Populus spp.) and willows (Salix spp), I never actually encountered P. cyanipes in the field and found just two specimens labeled simply “Mo” in the insect collection at the University of Missouri in Columbia. This puzzled me, as I had beaten countless branches of cottonwood (Populus deltoides) and willow in search of this species and found many of the other known poplar/willow associates. I had even already collected two specimens of its much rarer congener, P. thureura, off of a redbud tree at the entrance to the Entomology Building on campus while still in graduate school!
As is often the case, good comes to those who wait, and I’ve finally gotten my chance during the past two seasons to encounter this species in numbers—last year as prey taken from nest sites of the buprestid-specialist crabronid wasp, Cerceris fumipennis, and this past June on cottonwood trees in northwestern Oklahoma at Beaver Dunes State Park. The individual in these photos was the first one I found—beaten from the lower branch of a small, living cottonwood exhibiting significant branch dieback, and over the course of the next two days I managed to beat close to three dozen specimens from the small, stunted cottonwoods that dotted the park. I suspect that the combination of good timing—buprestids of many types were common on a number of woody plant species in the area—and susceptible hosts with abundant branch dieback due to protracted drought conditions over the past few years was the reason I was able to find so many of the beetles. A perfect storm for wood-boring beetles, so to speak!
As suggested above, larvae of this species are associated exclusively with dead or dying branches of Populus and Salix (both in the family Salicaceae), often in association with galls made previously by other species of wood-boring beetles, e.g., Saperda concolor in poplar (Knull 1920) and Agrilus criddlei in willow (Wellso et al. 1976). In fact, with one exception (P. viridicyanea on Chilopsis linearis) all members of the genus seem to be associated exclusively with plants in these two genera. However, in addition to these plants, Nelson et al. (2008), in their catalogue of the Buprestidae of the U.S. and Canada, also included black locust (Robinia pseudoacacia) in the family Fabaceae as a larval host for P. cyanea. I am convinced that this record represents at best a mere incidental adult association, and there are other examples of such in the catalogue (the final preparation of which was completed after the untimely death of the senior author). This is unfortunate, since erroneous records in such ‘standard’ references tend to be propagated in subsequent literature, which already seems to have happened in the case of black locust as a larval host for P. cyanipes (Paiero et al. 2012).
Knull, J. N. 1920. Notes on Buprestidae with description of a new species (Coleop.). Entomological News 31(1):4–12 [BioStor].
MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri. Insecta Mundi5(2):101–126 [pdf].
MacRae, T. C. 1994. Annotated checklist of the longhorned beetles (Coleoptera: Cerambycidae and Disteniidae) known to occur in Missouri. Insecta Mundi 7(4) (1993):223–252 [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].
Paiero, S. M., M. D. Jackson, A. Jewiss-Gaines, T. Kimoto, B. D. Gill & S. A. Marshall. 2012. Field Guide to the Jewel Beetles (Coleoptera: Buprestidae) of Northeastern North America. 1st Edition. Canadian Food Inspection Agency, 411 pp. [pdf].
Wellso, S. G., G. V. Manley & J. A. Jackman. 1976. Keys and notes on the Buprestidae (Coleoptera) of Michigan. The Great Lakes Entomologist 9(1):1–22.
Copyright © Ted C. MacRae 2013
4 thoughts on “Why did it take 30 years to collect these beetles?”
Re: P. viridicyanea on Chilopsis linearis.
Maybe the beetle only knows the common name of this shrub – Desert Willow – and got confused.
Seriously though, interesting host switch – Use something roughly in the same habitat (riparian) but a version of it where there aren’t usually Salicaceae (subtropical hot desert).
I didn’t go into it in the post, but I’m not convinced about the association with desert willow—which, as you intimate, superficially resembles but is not at all related to the true willows. The type series of P. viridicyanea consists of three males from southern California, one from Yermo and two from Palo Verde (Nelson 1997). The Yermo specimen was found “flying around cottonwoods” (certainly this refers to Populus trichocarpae), but the two Palo Verde specimens—collected at different times by different collectors—are labeled “from willow” and “reared from “desert willow”,” respectively. Nelson (1997) stated that the host ID of the latter was confirmed by its collector, but the fact that the other specimen is labeled simply “willow”—which I suspect refers to Salix lasiocarpa—and not “desert willow” suggests to me there may still have been some misinterpretation of the host identity. It could be a one-off rearing record—such things are known to happen, but considering that the species remains known from only these three type specimens, that Populus and Salix are quite rare in extreme southeastern California, and that Chilopsis is abundant in the area, I’m inclined to believe that this species also largely confines itself to salicaceous hosts.
Nelson, G. H. 1997. A new Poecilonota from southern California (Coleoptera: Buprestidae). The Pan-Pacific Entomologist 73(1):1–3 [pdf].
Hmmmm, oops? Unfortunate that there’s doubt in the host record we included from Nelson, but hopefully it won’t present much of a problem for those on the lookout for such a “commonly collected” species!
It’s not your fault – you took your information directly from what was supposed to be an “authoritative” source. The failure of the catalogue to deliver in that role is frustrating, and I can’t help but feel it was rushed to print without due diligence to ensure such errors didn’t become “fixed” in the literature. It’s one thing to publish mistakes in a primary paper but another to propagate them in a reference catalogue likely to be consulted by many for a long time to come.
Anyway, such issues don’t detract from the awesomeness that is the Jewel Beetle Guide! You guys have set the bar on what a taxon-specific guide should look like.