Acmaeodera carlota Fall – Coconino Co., Arizona
This is another of the interesting species that I encountered during my examination of material submitted for identification this past winter. Acmaeodera carlota is one of 149 species/subspecies in North America belonging to this very difficult genus (recall my recent post, Aaack!-maeodera), and as with so many of its congeners it wasn’t described until after the last revision of the genus more than a century ago (Fall 1899). Obviously, the genus badly needs another revision – or at least a revised key – so that the known species can be identified with some degree of confidence without having to send specimens to a specialist. There have been a handful of buprestid workers in recent decades who may have been able to accomplish this daunting task, but to date none have been willing to embrace this considerable challenge.
As far as is known, A. carlota occurs only in Arizona. Fall (1932) described this species from a few specimens collected from cactus blossoms near Globe, Arizona (~90 miles east of Phoenix). Since then, the only specific information recorded about this species was by Westcott et al. (1979), who reported adults cut from wood of Quercus dumosa near Sunflower (~60 miles northwest of the type locality) and collected from flowers in west-central Arizona near Wikieup. Fall’s original description leaves much to be desired (as is the case for nearly all original descriptions prior to the last 50 years or so), and to this point no images have been published in the literature or appeared on the web. This particular specimen was found in a batch of material sent to me by cerambycid-enthusiast Jeff Huether (the same batch containing the previously discussed Acmaeodera robigo), and the only reason I was able to identify it was by comparing it to a specimen given to me by the late Gayle Nelson, who collected the species near Wikieup after its occurrence was reported there by Westcott and colleagues. The interesting thing about this specimen is that it was collected near Page, Arizona – nearly 200 miles north of any of the previous known localities and just south of the Utah border. In suspect this species occurs even more broadly and is not, as the limited records suggest, restricted to Arizona.
Acmaeodera carlota belongs to a group of species that I loosely refer to as the A. tubulus-species group. It is not clear that all of the species are actually closely related, but they do all resemble each other in their small size (<8 mm), general appearance (i.e., black with confused yellow maculations on the elytra), and inclusion in the so-called ‘Truncatae’ group (a subdivision of the genus established by 19th Century coleopterist George Horn to include those species having the prosternal margin nearly straight and not retracted from the sides). Within the Truncatae, the species in the tubulus-species group are distinguished by lacking a subapical crest on the last ventral segment and general appearance. Only three species were known at the time of Fall’s revision (conoidea, neglecta, and tubulus); however, an additional eight species have been described since (carlota, ligulata, neoneglecta, opuntiae, parkeri, sabinae, starrae, and thoracata). I have collected many of these species in my travels across the southwestern U.S. and lack only starrae and thoracta in my collection (the latter is known only from the type). In the case of A. carlota, note the rather flattened dorsal surface that is densely clothed with long, stiff, dark, suberect hairs; the coarsely, contiguously punctate pronotum; and the subrugose, slightly irregular elytral intervals, which serve to distinguish this species from others in the group.
The group’s namesake, Acmaeodera tubulus, is widespread and common across the eastern U.S., making it relatively easy to identify. However, the remaining species of the tubulus-species group are limited to the south-central and southwestern U.S., and the lack of available identification keys and suitable descriptions makes them nearly impossible to identify except by comparison with determined specimens. As a result, I have built a key to the species in the Acmaeodera tubulus-species group that I use to assist in my own identifications. The key is based on distinguishing characters given in the original descriptions (if any) and augmented by my examination of the material at my disposal. I invite users to test the key with their own material and let me how well it works.
My sincere appreciation to Jeff Huether for allowing me to retain this specimen in my collection as a voucher for the range extension that it represents.
REFERENCES:
Fall, H. C. 1899. Synonpsis of the species of Acmaeodera of America, north of Mexico. Journal of the New York Entomological Society 7(1):1–37 [scroll to “Journal of the New York Entomological Society”, “v. 7 1899”, “Seq 12”].
Fall, H. C. 1932. Four new Buprestidae from Arizona. The Pan-Pacific Entomologist, 8(2) (1931):81-84.
Westcott, R. L., W. F. Barr, G. H. Nelson, and D. S. Verity. 1979. Distributional and biological notes notes on North and Central American species of Acmaeodera (Coleoptera: Buprestidae). The Coleopterists Bulletin, 33(2):169-181.
Copyright © Ted C. MacRae 2010
Beetles In The Bush 
Hi Ted
Nice find. Just shows you how little is known about Buprestidae even in the USA. Less taxonomy (i.e. arm chair biology) and more field work I say (hear this Chuck!). The relationships of buprestids to flowers and behaviour and their larval host plants as well as larval morphology will give great ideas about their true relationships, more so than DNA studies which in my opinion are mostly contrived and “doctored”! (in other words their cladograms are mostly fantasy to be compared with the “Alice in Wonderland” story by Lewis Carroll – most of these papers will end up in the dustbin of history). However, many biologists, especially in the USA and Australia, live in their own fantasy world, which is a shame. Part of the problem is that they are either botanists or zoologists and not both. In other words they are too narrow minded and don’t or are unable to see a real physical world.
Anyway, keep up the nice field work. I want to see more published studies on what the USA jewel beetles do and feed on in the field, both as larvae and adults. Field work I say! Field work!
Somebody in the USA should do a book on the USA fauna summarizing all that is known on ecology and host plant relationships. That would enthuse others and accelerate knowledge on these aspects.
Best regards, Trevor
PS> 150 species of Acmaeodera? Shouldn’t be too hard to fathom out! Try doing 450 species of Castiarina. More mess now that since S. Barker had dabbled in the group!
Hi Trevor – it’s amazing the things you find in the collections of those who specialize on other groups of insects.
Okay, I think you make a great point about many biologists being either botanists or zoologists, but not often both. It is the reason why there is still so much to learn about both adult and larval host associations in Buprestidae and other phytophagous insects. However, there have been good attempts – I followed in the footsteps of Gayle Nelson, who admonished me early to record host plant information as much as I could. And I wholeheartedly support your call for more field work (but will note that Chuck has spent as much or more time in the field with me as any entomologist I know).
I suggest, however, that DNA studies offer great potential in helping elucidate relationships. Not that they are a panacea and will replace the need for morphological, larval, and ecological studies – all are important, and any additional insight, however incremental, contributes to better understanding. It would be nice if all students of the family were well versed in both field and lab techniques, but this is neither practical nor necessary.
Actually, field studies may be the least neglected area of study – there are legions of collectors out scouring the bushes looking for insects. The problem is that they often lack a broader scientific interest in their ecology, and those that do often lack funds or opportunity to publish their findings. This represents a great resource for professional taxonomists that seems to me under-utilized.
Hi Ted
Yeah! Millions of collectors over the world but very little of their data ever gets into print! Although there are numerous reasons for this! And we all know some of them!
Arriving in the USA in 24 days! Will try to contact as many people as possible once I am there!
Best regards, Trevor
USA, huh? How long? Where you going? Bugs will be out in most places 🙂
Hi Ted
Arriving 5 April 2010 in Los Angeles, then traveling (flying) to Atlanta Georgia and then onto Nashville Tennessee, where I will base. I hope to travel via road during 24 days to a number of States including yours of Missouri! If all goes well, I may extend my visit.
Anything I collect I will donate to the USA museums of course. I will be bringing lots of presents with me (not beetles per se) but some of my vast amber fossil collection to donate to USA museums. I really do love giving out presents as you will find that I am a very generous person. Also I have many other plans, including some big ones, and some of which I will formulate on my long flight to the other side of the world!
I think I will good luck to many people I will meet on the trip!
I am very, very excited as I have planned this trip a long time ago.
Best regards, Trevor
PS. Would love to have a welcome commiteee either at Los Angeles or Nashville!
Hi Trevor,
Collecting is excellent throughout the southern states during April. Since you will be based in Nashville, bring your beating sheet and beat the heck out of the deciduous tree species – you should get a nice selection of our ~160 species of Agrilus.
Missouri is a tad too far north for good buprestid/cerambycid collecting during April – a few things start coming out, but things don’t really start getting going here until May. If you do want to come up sometime, let me know and we’ll figure something out.