Extreme sexual dimorphism in Buprestidae: Xenorhipis hidalgoensis

/ Ted C. MacRae / 11 Comments

Yesterday I received in the mail a package of specimens for identification from Dan Heffern in Houston, Texas. I first began corresponding with Dan about 25 years ago—not long after I myself became interested in Coleoptera, and as an avid collector of longhorned beetles (family Cerambycidae) Dan knows a thing or two about jewel beetles (family Buprestidae) as well. Over the years, Dan has come up with a number of great buprestid species from Texas, especially through rearing, many of which he has graciously sent to me examples for my cabinet.

Xenorhipis hidalgoensis (male, length 5.3 mm) | Hidalgo Co., Texas

The present package was no exception, as it contained a male/female pair of one of North America’s least frequently encountered buprestids, Xenorhipis hidalgoensis. Dan had reared them from dead branches of Condalia obovata collected in south Texas as part of a multi-year beetle survey in the Lower Rio Grande Valley. He had mentioned to me that he would be including them in the sending, but that did nothing to diminish my excitement upon seeing the specimens when I opened the box. The species was first described from Hidalgo Co., Texas (Knull 1952), and other than a single record from the neighboring Mexican state of Tamaulipas (Nelson et al. 1981) subsequent mentions of the species have been limited to catalogue listings and inclusion in keys to species. Thus, these specimens represent not only a nice addition to my collection, but also the first reported larval host for the species.

Xenorhipis hidalgoensis belongs to the tribe Xenorhipini, the males of which exhibit a distinctive specialization of their antennae in that the distal segments are highly modified into a very extended flabellate or lamellate condition. Females, in contrast, retain the serrate antennal condition that is more typical throughout the family.  Differences in antennal morphology aren’t the only sexual differences exhibited by members of the tribe, as males and females often exhibit differences in coloration as well. This is especially true in the genus Xenorhipis, and I’m not aware of a more striking example of this than X. hidalgoensis (compare these photos to those of male/female pairs of X. bajacalifornica, X. brendeli and X. osborni in A new species of Xenorhipus from Baja California).

Xenorhipis hidalgoensis (female, length 6.4 mm) | Hidalgo Co., Texas

The highly modified male antennae are interesting from both an evolutionary and functional standpoint. Similarly modified male antennae are found in a few other groups of Buprestidae, including the genus Knowltonia in western North America (four species), the monotypic genera Mendizabalia and Australorhipis in South America and Australia, respectively, and two species in the enormous Australian genus Castiarina (Bellamy and Nylander 2007). The Xenorhipini, however, with 20 species distributed throughout the Western Hemisphere, is by far the most diverse group exhibiting the condition. Despite the similarity of their antennae, the taxonomic distance between these groups and differences in the detailed structure of the numerous olfactory sensillae that cover the modified segments (Volkovitsh 2001) suggest that the modifications have arisen and evolved independently in these several disparate taxa.

All Buprestidae exhibit sensory structures on their antennae, presumably with olfactory and/or thermosensory functions; however, Wellso (1966) provided strong evidence that females of X. brendeli release pheromones that are highly attractive to males and detected by their elaborate antennae. Caging studies with virgin and mated females revealed that males were highly attracted to virgin but not mated females, and that mated males were not attracted to either virgin or mated females and died shortly thereafter.  Further, more than 80% of males were attracted within a 1-hour period just past midday. It is assumed that chemoreceptors for detecting female pheromones are located on the male antennae, as males with their antennae removed were not attracted to caged virgin females but were able to mate when caged with them. This suggests that the male antennae evolved in response to selection for greater surface area, which allows placement of more sensillae to detect female pheromone. Wellso observed also that adults are very short-lived, with no individuals living longer than 48 hours (perhaps due to reliance on pheromone attraction rather than longevity for mate location). This, along with their very short daily activity period, may explain  why adults of species in this tribe are so seldom encountered in the field.

Male with highly flabellate antennae

Female with unmodified serrate antennae



REFERENCES:

Bellamy, C. L. and U. Nylander. 2007. New genus-group synonymy in Stigmoderini (Coleoptera: Buprestidae). The Coleopterists Bulletin 61(3):423–427.

Knull, J. N. 1952. A new species of Xenorhipis from Texas (Coleoptera: Buprestidae). Entomological News 63(7):177–178.

Nelson, G. H., D. S. Verity, and R. L. Westcott. 1981. Additional notes on the biology and distribution of Buprestidae (Coleoptera) of North America. The Coleopterists Bulletin 35(2):129–152.

Volkovitsh, M. G. 2001. The comparative morphology of antennal structures in Buprestidae (Coleoptera): evolutionary trends, taxonomic and phylogenetic implications. Part 1. Acta Musei Moraviae, Scientiae biologicae (Brno) 86:43-169.

Wellso, S. G. 1966. Sexual attraction and biology of Xenorhipis brendeli (Coleoptera: LeConte). Journal of the Kansas Entomological Society 39(2):242–245.

Copyright © Ted C. MacRae 2012

2,171 pieces of chitin…

/ Ted C. MacRae / 12 Comments

Specimen boxes ready to ship out.

There are many reasons to look forward to the Holiday Season—time with family and friends, a break from the normal routine, the chance to engage in favorite activities leisure and otherwise, or maybe just kick back and not do much of anything. Okay, that last one is so not me—I really have a hard time sitting around and doing nothing no matter how tired I am. It makes me antsy. What did I do on my Holiday Break (a nice generous chunk of time starting the day before Christmas Eve and ending the day after New Years)? I spent lots of time with my family immediate and extended. I had quality time with a few close friends (including a 10-mile hike on the Ozark Trail with my friend Rich). I rode my bike. Lots! (315 miles precisely.) And (here comes the best part), I identified beetles. Lots! When I wasn’t riding or hiking or making merry, I was in my man cave with football on Tivo, beetles under the scope, and primary taxonomic literature sprawled all over the place. Maybe not the average Joe’s idea of a relaxing break, but it works for me.

Truth be told, I actually depend on the period between Thanksgiving and New Years Day to kick-start my winter curatorial season. As an entomologist with taxonomic leanings living in a temperate region, there is a seasonality to my activities. Summer is field season, and no matter what good intentions I may have for accomplishing other things, the constant siren call of the field makes this all but impossible. Reprints pile up. Boxes of specimens received for identification or exchange accumulate in the various nooks and crannies of the room. All the while I’m out collecting even more beetles! By the time fall arrives I’m well inundated and looking forward to the onset of winter so I can actually accomplish something other than growing the backlog.

It’s a new year, and with my plate now cleared of beetles needing identification, the specimens—all 2,171  of them—can be returned to their rightful owners. I’ve said it to each of them individually, but it bears repeating here that I truly appreciate the opportunity they give me to look at their material. Their specimens fuel my research with new data, allow me to gradually increase species representation in my collection, and occasionally even bring to light undescribed species. Without this network of collaborators, from full professors to citizen scientists, the Holidays for me would be just a bit too boring.

Copyright © Ted C. MacRae 2012

I am an Entomologist

/ Ted C. MacRae / 21 Comments

In my last post (Best of BitB 2011), I showed my favorite 13 insect (mostly) macrophotographs from 2011. Such “Best of …” posts have become an annual tradition here at BitB, and I like them because they give me a chance to review my photographs for the year and assess my progress as an insect macrophotographer. Others seem to like them also, as previous editions remain among this blog’s most popular posts despite the passage of time. Hopefully this latest edition will achieve similar popularity, and if it does I will be truly grateful.

Despite this, however, I find that I still have trouble considering myself a true “insect macrophotographer” rather than an “entomologist with a camera.” It’s not that I don’t want or hope to achieve such a moniker, and I’ve been thinking lately about why this should the case. I’ve realized that it really has less to do with self-opinion and more to do with the importance I still place on and satisfaction I get out of my other entomological pursuits. Not only have I been fortunate to find stable employment conducting entomology research, but I’ve also managed to find satisfying outlets for my avocational entomological interests. I am an Entomologist (with a capital ‘E’), and although I’ve enjoyed immensely my recent growth as an insect macrophotographer, I did have other other, purely entomological accomplishments in 2011 that I think also deserve mention:

  • Managing Editor of The Pan-Pacific Entomologist. It has been my life-long goal to become editor of a major entomology journal, and this past April I was presented with just such an opportunity with The Pan-Pacific Entomologist. My seven prior years as the journal’s Coleoptera Subject Editor prepared me well for the role (and further confirmed for me that the chief role was something I wanted to do), and in the seven months since I took over, the Editorial Board and I have processed 50 manuscripts, are about to submit files for our 4th issue, and have shaved more than two months off of the deficit that separates us from our eventual goal of on-schedule publishing.
  • Five papers published. With co-authors Chris Brown and Kent Fothergill, 2011 saw the publication of our series of papers assessing the conservation status of the tiger beetles Habroscelimorpha circumpicta johnsonii, Dromochorus pruinina, Tetracha carolina, and Cylindera cursitans in Missouri and Cylindera celeripes in the eastern Great Plains. Survey work for these species dominated my field activities during the past decade and formed the basis for these papers, and it was immensely satisfying to finally see the results of all that work finally appear in print. The real impact of this work, however, will be seen in the coming years as I work with conservation stakeholders who will utilize the information that we have gathered.
  • First seminar presented fully in Spanish. I don’t talk much about my professional activities—part of being an industry entomologist is the necessity to maintain company confidentiality. I have mentioned, however, my role in soybean entomology research and my recent travels to Argentina as part of this work. In November I finally realized one of my professional goals of giving a seminar fully in Spanish. It was a long time coming—I took Spanish lessons for a short time in the late 1990s but have otherwise had only one or two trips per year to Argentina and Mexico with which to improve my skills. It was during my trip to Argentina this past March that something finally ‘clicked’ and I found myself for the first time able to engage fully in conversation. My colleagues in Argentina must have noticed this as well, as it was they who requested that I not only give a seminar during my November visit, but that I do so in Spanish. The presentation went well, and I now find myself more motivated than ever to pursue what before seemed only a pipe dream—full fluency.
  • Senior Research Entomologist. After three decades of working as an entomologist—the last two in industry, I now can add “Senior” to my title. What this means in practice I’m not quite sure—I’m still doing largely what I have been doing for the past few years, and in this environment compensation is linked more to accomplishments than title. Maybe it’s just recognition of dogged persistence. Still, it sounds cool and looks good in the email signature line!
  • 32 species/subspecies of tiger beetles! This is the fun stuff! Nothing is more enjoyable for me than locating, observing, and photographing tiger beetles in their native habitats. It’s even better when they are uncommonly observed or rare endemic species. In 2011 I looked for tiger beetles in seven states (Arkansas, Colorado, Florida, Idaho, Missouri, Oklahoma and Utah), and of the 32 total species and subspecies that I found (listed below) the highlights must include three of North America’s rarest tiger beetle species: Cicindela albissima (Coral Pink Sand Dune Tiger Beetle), Cicindela arenicola (St. Anthony Dune Tiger Beetle), and the recently rediscovered Cicindelidia floridana (Miami Tiger Beetle).  Another eight endemic or highly restricted species and subspecies were also found, and I was able to obtain in situ photographs of all eleven in their native habitat (as well as most of the non-endemics that I had not already photographed). In the list that follows, bold text indicates endemics, and links to any photographs I posted are provided when available:
    • Genus Cicindela
      • Cicindela albissima Rumpp, 1962 [photos]
      • Cicindela arenicola Rumpp, 1967 [photos]
      • Cicindela formosa formosa Say, 1817
      • Cicindela formosa generosa Dejean, 1831 [photos]
      • Cicindela formosa gibsoni Brown, 1940 [photos]
      • Cicindela lengi lengi W. Horn, 1908
      • Cicindela purpurea audubonii LeConte, 1845
      • Cicindela scutellaris scutellaris Say, 1823
      • Cicindela scutellaris yampae Rumpp, 1986 [photos]
      • Cicindela sexguttata Fabricius, 1775
      • Cicindela splendida Hentz, 1830
      • Cicindela theatina Rotger, 1944 [photos pending]
      • Cicindela tranquebarica borealis E. D. Harris, 1911
      • Cicindela tranquebarica kirbyi LeConte, 1866
      • Cicindela tranquebarica tranquebarica Herbst, 1806 [photos]
    • Genus Cicindelidia
      • Cicindelidia floridana (Cartwright, 1939) [photos]
      • Cicindelidia haemorrhagica haemorrhagica (LeConte, 1851)
      • Cicindelidia obsoleta vulturina (LeConte, 1853) [photos pending]
      • Cicindelidia punctulata punctulata (Olivier, 1790)
      • Cicindelidia rufiventris rufiventris (Dejean, 1825)
      • Cicindelidia scabrosa (Schaupp, 1884) [photos]
    • Genus Cylindera
      • Cylindera (Cylindera) curistans (LeConte, 1860) [photos]
      • Cylindera (Cylindera) unipunctata (Fabricius, 1775) [photos]
    • Genus Ellipsoptera
      • Ellipsoptera hamata lacerata (Chaudoir, 1854) [photos, photos, photos, photos]
      • Ellipsoptera hirtilabris (LeConte, 1875)
      • Ellipsoptera marginata (Fabricius, 1775)
    • Genus Habroscelimorpha
      • Habroscelimorpha dorsalis saulcyi (Guérin-Méneville, 1840)
      • Habroscelimorpha severa severa (LaFerté-Sénectère, 1841)
      • Habroscelimorpha striga (LeConte, 1875) [photos]
    • Genus Tetracha
      • Tetracha (Tetracha) carolina carolina (Linnaeus, 1767) [photos]
      • Tetracha (Tetracha) floridana Leng & Mutchler, 1916 [photos, photos]
      • Tetracha (Tetracha) virginica (Linnaeus, 1767)

Copyright © Ted C. MacRae 2012

Best of BitB 2011

/ Ted C. MacRae / 20 Comments

Welcome to the 4th Annual BitB Top 10, where I get to pick my 10 (more or less) favorite photographs of the year. As an insect macrophotographer I still feel like a relative newcomer, although with three seasons under my belt fewer and fewer people seem to be buying it anymore. Granted I’ve learned a lot during that time, but the learning curve is still looking rather steep. I don’t mind—that’s the fun part! With that said, I present a baker’s dozen of my favorite photographs featured here during 2011. I hope they reflect the learnings I’ve had the past year and maybe show some progress over previous years (2009, 2008 and 2010).

One more thing—I’m including a special bonus for the first time in this year’s edition. Each of the photos shown below is linked to a 1680×1120 version that may be freely downloaded for use as wallpaper, printing in calendars, or any other use (as long as it’s personal and non-profit). It’s my way of saying thanks for your readership and support.

From  (posted 8 Jan). I’ve done limited photography with prepared rather than live specimens. However, the recreated aggressive-defensive posture of this greater arid-land katydid (Neobarrettia spinosa)—or “red-eyed devil”—was too striking to pass up. A clean background allows every spine and tooth to be seen with terrifying clarity.

From  (posted 6 Feb). I had never seen a cactus fly until I encountered this Nerius sp. I’m especially fond of the bizzarely-shaped head and un-fly-like spines on the front legs.

From  (posted 17 Feb). This photo of a fungus weevil, Phaenithon semigriseus, is one of the first where I nailed the focus right on the eye at such a magnitude of closeup (~3X) and also got the composition I was looking for. I didn’t notice at the time, but the beetle seems to be “smiling.”

From  (posted 28 Mar). One of the field techniques I’ve been practicing this year is actually holding the plant with the subject in one hand, resting the camera on my wrist and controlling it with the other hand, and manipulating the position of the plant to achieve a desired composition. It’s a difficult technique to master, but the results are worth it. The jumping spider, Euophrys sutrix, represents one of my earliest successful attempts with this technique.

From  (posted 30 Mar). This South American tree fruit weevil looks like it is sitting quite calmly on a branch. In reality, it never stopped crawling while I attempted to photograph it. Crawling subjects are not only difficult to focus on but also almost always have a “bum” leg. I achieved this photo by tracking the beetle through the lens and firing shots as soon as the center focus point flashed, playing a numbers game to ensure that I got at least one with all the legs nicely positioned. I’d have been even happier with this photo if I had not clipped the antennal tip.

From  (posted 4 May). Face shots of predatory insects are hard to resist, and in this one of the fiery searcher beetle, Calosoma scrutator, the angle of the subject to the lighting was perfect for showing off every ridge and tooth in its impressive mandibles.

From  (posted 10 May). I’ve taken plenty of lateral profile shots of tiger beetles, but I like this slightly panned out one especially because of the sense of scale and landscape created by the inclusion of the plantlets and the view over the small rise.

From  (posted 18 May). I found these Edessa meditabunda stink bug eggs on the underside of a soybean leaf in Argentina almost ready to hatch. The developing eye spots in each egg gives the photo a “cute” factor rarely seen in such super close-ups.

From  (posted 15 July). Some of my favorite insect photos are not only those that show the bug in all its glory, but also tell a story about its natural history. This nymphal lichen grasshopper, Trimerotropis saxatilis, is almost invisible when sitting on the lichens that cover the sandstone exposures in its preferred glade habitat. 

From  (posted 23 Aug). I know this is the second beetle face shot I’ve included in the final selections, but it was while photographing this rare Florida metallic tiger beetle, Tetracha floridana, in the middle of the night that I discovered the use of extension tubes to improve the quality of flash lighting (decreased lens to subject distance results in greater apparent light size). This is perhaps one of the best illuminated direct flash photographs that I’ve taken, and I also like the symmetry of the composition.

From  (posted 17 Sep). The three-cornered alfalfa hopper (Spissistilus festinus) is a common pest of alfalfa and soybean in the U.S. However, despite its abundance, I’ve never noticed the bizarre zig-zag pattern of the eyes until I took this photo. Even though both the insect and the background are green, there is sufficient value contrast to create a pleasing composition. Bumping up the ISO and a lower FEC setting prevented overblowing the light greens—easy to do with full flash macrophotography.

From  (posted 4 Oct). This longhorned beetle had settled in for the night on its Ericamera nauseosa host plant, allowing me to use higher ISO and lower shutter speed settings with a hand-held camera to achieve this very pleasing blue sky background, while retaining the sharpness of detail of the subject that comes from full-flash illumination. The blue sky background provides a more pleasing contrast with the colors of this particular beetle and flowers than the black background that is more typically seen with full-flash macrophotography.

From  (19 Dec). An uncommon underside view of these purple tree fungus (Trichaptum biforme) caps and use of flash illumination allows the colors to literally glow against the bright green lichens also growing on the tree. Keeping aperture at a moderate setting allows blurring of the caps further back, adding three-dimensionality to the photo and preventing it from looking ‘flat.’

Well, there you have it, and I hope you’ve enjoyed my selections. Please do tell me if you have a favorite among theses (and if there were other photos posted during 2011 that you think deserved making the final selections).

Copyright © Ted C. MacRae 2011

Hover fly on mallow flower

/ Ted C. MacRae / 17 Comments

I’ve mentioned before my reluctance to take random “bug on a flower” photos, but the colors of this hover fly (family Syrphidae) and the mallow flower (Malvaceae, possibly Abutilon pauciflorum) on which it was sitting were enough to capture my interest—a rare offering from this blog to dipterophiles. Even though I’m a beetle man, I’ve had reasonably good success identifying the varied insects across several orders and families that I’ve photographed at the Reserve. This one, however, has me a little stumped. I searched the syrphid gallery at Diptera.com but didn’t find a good match, the most similar being the Old World species Episyrphus balteatus. My best guess is something in the tribe Syrphini. Morgan? Keith? Phoridae?

Photographed last month at  in Buenos Aires.

Copyright © Ted C. MacRae 2011

A Riot of Colors

/ Ted C. MacRae / 5 Comments

Turkey tails (Trametes versicolor) on lichen-encrusted trunk of fallen post oak (Quercus stellata)—ventral view.

For my friend Rich and I, Thanksgiving week marks the official beginning of the winter hiking season.  Fifteen years ago we began our quest to hike the entirety of the Ozark Trail, and with only ~50 of the 350 miles constructed to this point in Missouri to go we find ourselves tantalizingly close to reaching that goal. This year we started the season with 10+ miles of the northernmost Courtois Section. The rains of the previous few days had stopped, but the moisture-laden air still hung heavy under gray, overcast skies.  Such a day may not be considered optimal for photography, but nothing could be further from the truth. Lichens and fungi, normally muted and inconspicuous, spring to life when awash with moisture and splash the woodlands with a riot of colors rarely seen on dry, sunny days. The dark, almost black, color of the wet bark adds to the contrast and further emphasizes the ubiquity of these “lower forms of life” amongst the now leafless trees.

Among the most distinctive of these is turkey tail (Trametes versicolor), an extraordinarily common polypore fungus that grows on the trunks of declining and dead deciduous trees—especially oaks. Like all polypore fungi, turkey tail feeds saprophytically within dead and dying wood but is more familiar to us by way of its externally produced reproductive structures, or “tails,” for the release of spores. As the specific epithet suggests, turkey tail comes in a variety of colors ranging from gray through browns to black, and the association of older tails with algal growth even adds greens to the mix. The diversity of colors is found not only within a single locality, but even on a single tree! The especially colorful example shown in these photos, made even more so by its intermixture with green crustose lichens, was found on the trunk of a post oak (Quercus stellata) tree that had fallen across the trail, and I couldn’t help but marvel at the range of colors present and the contrast between the dorsal and ventral surfaces.

Update 30 Dec 2011: Kathie Hodge has provided the following correction to my identification:

Hate to tell you, but the turkey tails in your post aren’t turkey tails, alas, they’re Trichaptum biforme. It’s one of a bunch of shelf fungi that resemble true turkey tails.  You can tell them apart by the small, regular pores of Trametes, whereas Trichaptum has a rugged toothy thing going on.  Also, T. biforme is paler on top, not as strongly zonate, and has a distinctly purple growing edge (and sometimes the hymenium is delightfully purple too).

Thank you, Kathie, for keeping me on the straight and narrow (and maybe I should stick with beetles in these quizzes!).

Natural light (ISO1600, f/5.6, 1/60 sec)

Full flash (ISO160, f/16, 1/200 sec)

Of course, color is a matter of perception, and I wondered what effect lighting would have on this. When it comes to macrophotography I’m an unapologetic flash-man, preferring the flexibility and sharpness of detail that flash lighting offers over the dreamier “natural” images produced with strictly ambient light. The above comparison, looking at the dorsal surface of the tails with their characteristic concentric zones of colors, did nothing to change that opinion. While some might insist that the natural light photo is a truer representation of the actual colors witnessed, to me it looks gray and faded—no doubt a result of illumination by a large gray light source (the cloudy sky). While my eyes might have seen muted shades of gray and brown, my mind saw vivid shades of rust, orange, and green—colors captured more faithfully by the full-flash illuminated photo.

The strikingly zonate upper surfaces present contrasts in texture as well as color

Congratulations to those of you who guessed some kind of polypore fungus in Super Crop Challenge #10, although nobody correctly deduced an ID below the family level. I fear my challenges have gotten too difficult, as this is the  in which nobody arrived at the correct answer. Nevertheless, on points Mr. Phidippus takes top honors with 11, while Roy, Tim and John earned enough points to receive podium mentions. Session 5 overall leader, Marlin, didn’t play this time, so Mr. Phidippus now takes over the top spot—can he hold onto it as the session plays out?

Copyright © Ted C. MacRae 2011

Super Crop Challenge #10

/ Ted C. MacRae / 22 Comments

It’s gotten a little quiet around here lately, and since we haven’t done a Super Crop Challenge for awhile let’s see if this latest version will liven things back up. This challenge strays a bit from my normal scope, so I’m not sure how difficult or easy it will prove to be. I’ll award 2 pts for all correctly stated primary rank taxa (what a mouthful!)—standard challenge rules apply, including moderated comments to give everyone a chance to submit their answers.  Bonus points will be awarded to early birds if multiple participants arrive at the same correct answer, and possibly also for other relevant comments (at my discretion). Good luck!

Copyright © Ted C. MacRae 2011