Pseudoxycheila tarsalis – remounted

Posted on December 21, 2010 by Ted C. MacRae

Pseudoxycheila tarsalis (Central American montane tiger beetle) | specimen ex. Costa Rica.

I tend to be a minimalist when it comes to mounting beetles. That is, I mount them so that they take up minimal space – legs tucked neatly and symmetrically against each side of the body and antennae laid straight alongside each elytron. This is important not only for space considerations (always a premium, but especially so in a private collection), but also to minimize the chances of accidental breakage when handling specimens. I must admit that beetles mounted in such manner don’t have quite the visual appeal of beetles mounted in a more relaxed, life-like position, but the ability to pack them tightly in my limited drawer space generally overrides whatever aesthetic desires I may have. Every now and then, however, I come across a specimen that just begs to be mounted life-like due to its striking appearance or impressive structures. Pseudoxycheila tarsalis (Central American montane tiger beetle), which I recently received as a gift from Henry Hespenheide, is one such species.

Remounting a dry, already-mounted beetle is a little trickier than mounting a fresh specimen. The beetle must first be relaxed, and even when relaxed well the beetle is never as pliable as when fresh. This makes it more difficult to get the legs and antennae into the desired position, and there is always a higher risk of breakage while trying to do so. Many different methods for relaxing beetles are available – some better than others, but for a one-off specimen I usually just soak it in very warm tap water. Generally 15-20 minutes will suffice, although large specimens may require more than this. Soaking has the added benefit of softening whatever debris might be caked onto the beetle so that it can be removed more easily. In this case, once the beetle was relaxed I used forceps to hold the specimen by the pin to keep it submerged in the water while “scrubbing” its upper surface with a camel-hair brush. Younger eyes might be able to do this unaided, but I find a binocular dissecting scope at low power to be quite helpful.

Once clean, I inserted the pin into a styrofoam block for positioning of the body parts. Since this specimen was to be posed in a life-like position, I didn’t insert the pin all the way, but rather left the body up off the styrofoam as it would be in life. Also, my favorite tiger beetle pose is slightly elevated on the front legs, so I inserted the pin at an angle to leave more space under the head than the abdomen. Then it was a matter of using brace pins to hold each body part in the desired position. I work from “sturdy” to “delicate” – i.e., the sturdiest body parts are placed in position first and the most delicate are done last, since positioning the sturdier parts causes tugging and pulling that could break the more delicate parts if they are already braced in position. This usually means bracing the body itself first, then then the legs, and lastly the antennae. Again, my eyes prefer to do this under a scope. While the antennae and tarsi can usually be positioned directly with the brace pins, sturdier body parts may need to be positioned and held in place with fine-tipped forceps in one hand while placing brace pins around them with the other hand. I also work “proximal to distal” with each part – i.e., positioning the part closest to the body first, followed by the more distal portions. There’s no way around it – this kind of work takes practice and patience, and even with all my years of experience I still managed to break off the distal four antennomeres from the left antenna (and failed in my attempt to glue them back on after drying). For this specimen, a total of 42 brace pins were used.

While fresh specimens may take several days (to a week or more for large specimens) to dry, relaxed specimens usually dry much more quickly – overnight was more than adequate for this specimen. Be careful when removing the brace pins! If you grab them too tightly as you pull them out of the styrofoam, you can end up “flicking” a leg or antenna and breaking it – better to grab the pin head loosely and lightly spin it back and forth as you pull up gently until the pin is free. Once all the brace pins are removed, pull up carefully on the main pin as well until you’re sure the tarsal claws aren’t grabbing the styrofoam – if they are, slide a pin or forceps underneath and gently unhook the claws before pulling the pin out any further. Replace the labels and voila – a much more aesthetically pleasing specimen! Is all this effort worth it? You be the judge. Below on the left is the photograph I showed previously for the specimen prior to cleaning and remounting, while on the right is the now clean and nicely mounted specimen.

Before

After

With the beetle in its new life-like position (and scrambling for any chance to get some more practice with my new diffuser setup [photos coming soon, I promise!] as I slide into the depths of this Midwestern winter), I couldn’t resist the urge to take a few studio shots of the remounted beetle “on white.” While photographs of posed, dead beetles may not be to everyone’s liking, they do provide a chance to see detailed views of species that may not be otherwise available. The first photo above and the three below are some of my favorites from the session:

Photo Details: Canon 50D, Canon MT-24EX flash w/ DIY diffuser (photos 1, 7-8: Canon MP-E 65mm 1-5X macro lens, ISO 100, 1/250 sec, f/13; photos 2-6: Canon 100mm macro lens, ISO 100, 1/250 sec, f/16). Typical post-processing (levels, minor cropping, unsharp mask) with digital removal of pin heads and minor debris.

Copyright © Ted C. MacRae 2010

Posted in Cicindelidae, Coleoptera | Tagged , , , , , | 34 Comments

AIF #11, HoH #12

Posted on December 19, 2010 by Ted C. MacRae

An Inordinate Fondness #11 – Kindergarten Kunstkammer is hot off the press, and you MUST read it! Adrian Thysse, the polymath behind The Bug Whisperer (as well as Voyages Around My Camera, A Natural Evolution, and Antoni van Leeuwenhoek Centraal), adopts an appropriately Renaissance theme to this latest AIF issue.  It seems that one “Theodosius Macraeinius” spilled his gift box of beetles in Ferrante Imperato’s private museum (“Kunstkammer”) before properly curating its rare contents and needs help from the readers to locate and “pin” them. Intrigued? Take a look for yourself and see if you can find each of the 12 rare beauties – successfully pinning them brings up a delightful post about the beetle and the particulars of its “collection.” Bravo, Adrian!

One month older than AIF is House of Herps, which celebrates The First Anniversary Edition at the home site.  To celebrate, the home site has undergone a design change and introduces two new badges to go with the original one – for some reason I feel partial to this one.  This month’s contributors bring to 52 the total number of contributors that have participated in the inaugural year of HoH, sharing their pictures, experiences and knowledge about the world’s amphibians and reptiles.  If this carnival has accomplished anything, I hope it has been to stimulate interest in these ancient animals (it certainly has in me) and to highlight their increasingly tenuous circumstances in the face of human pressures.  Join me in making HoH’s second year as successful as its first.

Copyright © Ted C. MacRae 2010

Posted in [No taxon] | Tagged , , , , , , | 2 Comments

ESA in absentia

Posted on December 17, 2010 by Ted C. MacRae

Click on image to see larger version.

The Entomological Society of America (ESA) held its 58th Annual Meeting earlier this week in San Diego, California. For those of you who were unable to attend, I’ve included a link to a poster that I and coauthors Chris Brown and Kent Fothergill presented, titled Cylindera cursitans: Distribution and Seasonal Occurrence in Southeast Missouri. Okay, I can already see the puzzled faces, as many of you know I was unable to attend myself. In fact, none of the poster authors were in attendance – if Kelly Tindall, Kent’s entomologist-wife, hadn’t attended the meetings the poster would have never seen the light of day.

Despite lead authorship on the poster, I had a minimal role in its preparation.  Kent did much of the dirty work – clipping text and figures from a manuscript on the subject that we recently submitted to the journal CICINDELA, while Chris and I sat back and gave thumbs up and thumbs down opinions on each iteration of Kent’s hard work.  My heartiest congratulations to Kent for producing such a nice piece of work, to both Kent and Chris for putting up with my obsessive nitpicking over every trifling detail as we readied the manuscript for submission, and to Kelly for lugging a poster halfway across the country in the middle of winter when it didn’t even have her name on it.

REFERENCE:

MacRae, T. C., C. R. Brown, and K. Fothergill.  2010. Cylindera cursitans: Distribution and Seasonal Occurrence in Southeast Missouri. Annual Meeting of the Entomological Society of America, San Diego, California, December 12-15, 2010.

Copyright © Ted C. MacRae 2010

Posted in Cicindelidae, Coleoptera | Tagged , , , , , , | 6 Comments

A First Class Box of Beetles

Posted on December 16, 2010 by Ted C. MacRae

Warning: post contains lots of hardcore, beetle-collector geekery!

A nice selection of tiger beetles and buprestid beetles.

A few weeks ago I got an email from fellow buprestophile Henry Hespenheide (Professor Emeritus, UCLA) asking if I needed any specimens of Agrilus coxalis auroguttatus – recently dubbed the “goldspotted oak borer” after it was discovered damaging oaks in southern California (Coleman & Seybold 2008).  I replied that I did not have this species in my collection and that I would be grateful for any examples he could provide.  Shortly afterwards, I received another message from him saying that he had just placed in the mail a small box with a male/female pair of that species – along with about two dozen tiger beetles for my enjoyment!  Later that week I received the shipment at my office – I couldn’t wait to open it up and see what goodies were inside!

Ctenostoma maculicorne (Chevrolat, 1856)

Opening a box of just received specimens is a little like opening presents on Christmas – you don’t know for sure what’s inside, but you know you’re gonna like it!  This time was no exception, and I delighted as I realized the sending contained a dozen or so tiger beetles from Costa Rica and Nicaragua (a region in which Henry has spent many of his years studying the leaf-mining and twig boring buprestid beetles).  My eyes were immediately drawn to two tiger beetles in particular – specimen #1 in the first row, and specimen #4 in the second row.  Why these particular tiger beetles?  Obviously they are among the more showy specimens in the sending, but more significantly both of them belong to genera not represented in my collection.  The first of these is Ctenostoma maculicorne, representing also a new tribe for my collection (Collyridini, subtribe Ctenostomina).  I’m glad Ron Huber had already identified this specimen, as I probably would’ve only been able to determine the genus.  Beetles in this group are ant mimics, but in a much different manner than our U.S. ant-mimics (Cylindera cursitans and Cylindera celeripes).  Those latter species are found strictly on the ground (as are all U.S. tiger beetle species), while species of Ctenostoma are largely arboreal.  Troy Bartlett at Nature Closeups has some great photographs of another species in this genus seen last January in Brazil (Caraça Natural Park, Minas Gerais) that show just how ant-like these beetles can appear as they crawl about on twigs and branches.

Pseudoxycheila tarsalis Bates, 1869

Despite lacking an identification label, I recognized the second specimen instantly as Pseudoxycheila tarsalis, dubbed by Erwin & Pearson (2008) as the “Central American montane tiger beetle.”  Pseudoxycheila is a rather large Neotropical genus (21 known species), but only P. tarsalis occurs north of South America.  Morgan Jackson at Biodiversity in Focus photographed an individual of this species during his visit to Costa Rica this past summer.  Its brilliant coloration is not only delightful to look at but also apparently aposematic in nature – Schultz and Puchalski (2001) found that benzene-like compounds isolated from the beetle’s pygidial glands are distasteful to humans, adding support to the potential of a Müllerian mimicry association with stinging mutillid wasps in the genus Hoplomutilla, which they resemble.  Note also the curious spine on the frons extending out over the mandibles – maybe it not only grabs its prey with its toothy jaws but also “stabs” it for extra measure (just kidding – though I do wonder about the function of that spine.  I’m not aware of its presence in any other genus of tiger beetles).

I also noted an interesting pair of tiger beetles that looked very different from each other, yet were both identified by Ron Huber as Tetracha ignea.  This species was recently synonymized under the nominotypical form of T. sobrina (Naviaux 2007) – the “ascendent metallic tiger beetle” (Erwin & Pearson 2008), a highly variable species with numerous described subspecies occurring in southern Mexico, Central America, northern South America, and the West Indies.  The specimen on the left has the normal appearance of T. sobrina sobrina, but the specimen on the right looks like it might have suffered some chemical discoloration (a common occurrence among collected tiger beetle specimens).

Update 16 Dec 2010, 12:00pm – I just learned from Henry that the Tetracha specimen on the right (from Nicaragua) was not seen by Ron Huber and, thus, is likely not conspecific with the specimen on the left (T. sobrina from Costa Rica).  That’ll teach me to blindly accept what I see but does not seem right.  Now, time to pull out my copy of Naviaux (2007) and test my abilities to work through a key written in French!

Tetracha sobrina sobrina Dejean, 1831 (L); Tetrach sp. undet. from Guatemala (R).

There are several other interesting species in the sending – some determined (two species each of Oxycheila and Brasiella) and others that I need to look at more closely.  You may note on the bottom row a few specimens of a species of Elaphrus – a genus of true ground beetles that often fool collectors by their strong resemblance to tiger beetles (looks like they fooled Henry, too).  As for the beetles that were the reason for this shipment in the first place, these are shown in the image below.  Agrilus coxalis auroguttatus was recently discovered as the cause of significant mortality in several species of oak trees in San Diego County (Coleman & Seybold 2008), thus joining the introduced Agrilus planipennis (emerald ash borer) and several native Agrilus spp. on the ever-growing list of buprestid beetles achieving economic pest status in North America.  This subspecies, known for many years from southern Arizona (where it is not a pest), is curiously widely disjunct from nominotypical populations in southern Mexico.  Its sudden appearance in southern California has all the hallmarks of being a human-aided introduction, although natural range expansion remains a possibility.

Agrilus coxalis auroguttatus Schaeffer, 1905

My deep appreciation to Henry Hespenheide for gifting me these specimens and for his always enlightening and often entertaining correspondence over the years.

REFERENCES:

Coleman, T. W. and S. J. Seybold.  2008.  Previously unrecorded damage to oak, Quercus spp., in southern California by the goldspotted oak borer, Agrilus coxalis Waterhouse (Coleoptera: Buprestidae).  The Pan-Pacific Entomologist 84:288–300.

Erwin, T. L. and D. L. Pearson. 2008. A Treatise on the Western Hemisphere Caraboidea (Coleoptera). Their classification, distributions, and ways of life. Volume II (Carabidae-Nebriiformes 2-Cicindelitae). Pensoft Series Faunistica 84. Pensoft Publishers, Sofia, 400 pp.

Naviaux R. 2007. Tetracha (Coleoptera, Cicindelidae, Megacephalina): Revision du genre et descriptions de nouveaus taxons. Mémoires de la Société entomologique de France 7:1–197.

Schultz, T. D. and J. Puchalski.  2001.  Chemical defenses in the tiger beetle Pseudoxycheila tarsalis Bates (Carabidae: Cicindelinae).  The Coleopterists Bulletin 55(2):164–166.

Copyright © Ted C. MacRae 2010


Posted in Buprestidae, Coleoptera | Tagged , , , , , , , , , , | 31 Comments

Cleaning Tiger Beetles

Posted on December 14, 2010 by Ted C. MacRae

Cicindela scutellaris scutellaris - the festive tiger beetle

This is Cicindela scutellaris (festive tiger beetle), one of the six species of tiger beetles that we found last September at Monroe Canyon in the Pine Ridge area of northwestern Nebraska.  The red elytra and green head and pronotum are characteristic of nominotypical populations of this species that are found in sandy habitats throughout the Great Plains.  This is your classic tiger beetle in a classic tiger beetle pose; however, photographs such as this are not so easy to come by.  The biggest challenge is the beetle itself – rarely are they so accommodating to allow this nice lateral profile perspective with the head slightly cocked towards the camera while standing up on their front legs.  This posture is seen only when the beetles are warm and active, and warm beetles are skittish beetles that yield lots of not-as-interesting back shots (head directed away from the camera) as they persistently run away from the photographer.  Cooler temperatures make them less skittish and easier to approach from the desired angle, but in this case they often lay flat on the ground trying to absorb heat – flay-laying beetles are not very photogenic either.  With practice and patience, one learns how to “work” an active, skittish subject and get them accustomed to the photographer so that the above perspective can be achieved.

Getting the shot, however, is only half the battle.  Tiger beetles are dirty bugs!  They run around over bare ground and dig in it, often leaving them covered with debris.  This is particularly true for species that frequent sandy habitats.  For those of us who like to photograph wild individuals in their native habitats, debris-covered beetles is something we have to live with.  Or do we…?  The beetle in the above image looks squeaky-clean thanks to some simple digital image processing tools that I used to “clean up” the subject (I use Photoshop Elements 6.0).  Now, I’ve never been one to want to spend a lot of time on post-processing of my photographs.  I’d rather be looking for bugs, photographing them, studying them, and writing about them – time spent on post-processing is time not spent on any of these other activities.  However, I have developed a little routine that I follow for most of my tiger beetle photographs now that cleans them up a bit – some more than others – and doesn’t take too much time.  Maybe some of you will find this useful for your own photographs.¹

¹ Disclaimer:  I am not a Photoshop expert.  I’m not even a photographer.  I’m an entomologist with a camera.  As a result, this post is intended to be not so much an authoritative tutorial on the use of Photoshop as a summary of what I’ve learned in dealing with my own photographs.  Constructive dialogue about these and other techniques is welcome. 

Like it or not, no digital image comes out of the camera ready to use (still perhaps the most perplexing aspect of this whole digital photography thing for me personally).  Almost every image needs some levels adjustment and unsharp mask applied to it, and while others are against it I’m not above doing a little cropping to enhance the final composition of the photograph (hey, it’s difficult enough just getting these guys in the frame, much less positioned exactly where you want them).  These are the basic steps that I follow for almost every photograph, as illustrated in the following sequence (reduced versions used for all photos):

Original photograph before processing.

Slight cropping to enhance composition.

Levels adjusted to brighten photo.

Unsharp mask applied (amount = 80%, radius = 2.0 pixels, threshold = 12 levels).

 Normally I would be done at this point, but there are two things that bother me about this photo: 1) the dark shadow on the distal back portion of the elytra (common with this pose), and 2) the debris scattered about on the eye, mandibles, thorax, and elytra.  To fix the shadow, I used the Magic Wand Tool (set on contiguous) to select the shadowed area of the elytra, then used the Dodge Tool set on Highlights (exposure = 25%) to lighten the shadowed area.  For the debris, I enlarged the photo to 100% and used the Spot Healing Brush Tool to remove most of the sand particles, adjusting the size of the brush to just larger than the size of the individual sand particles.  This works fine for particles surrounded by a uniform background, but it doesn’t work so well for particles along edges (particularly the mandibles).  For this, I used the Clone Stamp Tool (again, with the photograph enlarged to 100%) and carefully “cloned” a clean spot along the edge of the mandible next to the sand particle and then replaced the piece of debris with the cloned piece of the image.  As with the Spot Healing Brush Tool, the pixel size is set to the smallest size needed for the size of the debris particles.  Compare the above image with the finished image below to see the difference.

Finished photo with dark shadows on elytra and sand debris on body removed.

 The biggest improvements can be seen with the eyes, always the focal point of a photo such as this, and the mandibles – both now appearing nice and clean.  Is this cheating?  Have I compromised my ideal of getting an image of a wild individual of this species in its native habitat?  I’d be interested to know your opinion about this.

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/16), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers.

Copyright © Ted C. MacRae 2010

Posted in Cicindelidae, Coleoptera | Tagged , , , , , | 22 Comments

Eye of the Turtle

Posted on December 10, 2010 by Ted C. MacRae

Adult male three-toed box turtle (Terrapene carolina triunguis).

Is there anything more lovable than the humble turtle?  As old as the dinosaurs, they stumbled onto a body plan that works and promptly dropped out of the evolutionary arms race.  Slow, plodding, and seemingly oblivious, they steadfastly cling to their quite, unhurried lives.  As the rest of the earth’s diversity of life races on, turtles go about their business much as they have done for more than 200 million years now.  They are survivors.

My friend Rich and I encountered this three-toed box turtle (Terrapene carolina triunguis) during our hike of the lower North Fork Section of the Ozark Trail in extreme southern Missouri.  Three-toed box turtles are one of four U.S. subspecies of the eastern box turtle, occupying the area west of the Mississippi River from Missouri and Kansas south to Texas and distinguished by their largely unpatterned shell and – yes, three toes on the hind legs rather than four.  I walked right by this guy the first time without noticing him, and only when I turned around to go back and look at something else did I see him sitting there – neck fully extended.  Box turtles exhibit considerable variability in color and patterns on the head and neck, and this particular individual is one of the more conspicuously colored that I’ve seen.

And the eye – as red an eye as I’ve ever seen!  Almost surely a male, as females may have some red in the eye but rarely to such a spectacular degree.  Also likely full-grown based on his rather large size, though probably not too advanced in age yet since the growth rings were still easily visible (in older turtles the growth rings gradually wear smooth).  I estimated it at about 12 years based on ring counts – still a far cry from the 30-50 years that are not uncommonly documented.  He kept a watchful eye on me as I studied him, and I wondered about what his future held.  As an adult, he has settled into a small home range from which he rarely ventures – likely visible to me in its entirety from where I stood.  For the next several decades, he will amble across this single hillside on an endless quest for earthworms, strawberries, and mushrooms.  Save for a possible run-in or two with a destined-to-be-frustrated coyote, fox, or racoon, it will be a largely uneventful life.  He is a survivor.

Copyright © Ted C. MacRae 2010

Posted in Reptilia, Vertebrata | Tagged , , , , | 60 Comments

Monroe Canyon – A Tiger Beetle “Hot Spot”

Posted on December 8, 2010 by Ted C. MacRae

Steep, sparsely vegetated, fine sand road cut on the Nebraska Pine Ridge escarpment.

The vast landscape surrounding the Nebraska Pine Ridge boasts two entirely different natural communities – the High Plains shortgrass prairie atop the ridge stretching endlessly to the south, and the eerie, desolate Badlands on the north side of the ridge extending to the Black Hills of South Dakota.  Separating these two distinctive communities is the Pine Ridge escarpment itself – a precipitous 1,400-ft drop whose ponderosa pine forests and sage brushlands are more reminiscent of the Rocky Mountains some distance to the west rather than the Great Plains that surround them.  Instead of hard igneous and metamorphic rocks, however, the Pine Ridge is composed of soft, erodable sand- and siltstones, giving rise to canyons with dramatic white bluffs and escarpments.  One of the more scenic of these is Monroe Canyon, located six miles north of the tiny town of Harrison and part of the Gilbert-Baker State Wildlife Management Area.  I first explored Monroe Canyon two years ago, when Matt Brust took me there after our successful quest to see Cicindela nebraskana (prairie long-lipped tiger beetle) in the prairies above.  The steep, eroded road cuts in Monroe Canyon had become one of Matt’s favorite spots to look for tiger beetles, but on our visit there was not much going on save for single individuals of the ubiquitous sand-loving species Cicindela formosa (big sand tiger beetle) and Cicindela scutellaris (festive tiger beetle).  Still, the fine, deep, sparsely vegetated mixture of sand and silt extending far up the embankment is classic tiger beetle habitat, so when Chris Brown and I returned to the area this past September, we decided to give Monroe Canyon another try.

Of the several sand-associated tiger beetles that I thought we might encounter here, Cicindela lengi (blowout tiger beetle) was the one I was really hoping for.  I had encountered a few scarce individuals of this C. formosa-look alike during my 2008 trip and eventually reared another individual from suspected larvae plucked from their burrows.  My only photographs of this species, however, were taken during my PNS days, and I longed to see them once again through the viewfinder of a proper macro-rig.  The day hadn’t started well, getting skunked at a clay bank site in Crawford on the way to Monroe Canyon (where I resorted to photographing itty bitty little moths), and early indications once we got to Monroe Canyon were that it was going to be slow there as well.  Sporadic sightings of Cicindela purpurea audubonii (Audubon’s tiger beetle) had me yawning, and a lone individual of the remarkably infidel Cicindela ubiquita [= C. punctulata] (punctured tiger beetle) seen close to the roadside did little to boost my enthusiasm.  Still, conditions just seemed “right” and the habitat was extensive enough that it deserved a thorough searching before passing judgement.  I got a little more excited when I encountered a few C. purpurea audubonii black morphs, of which I got my first nice field photographs (you’ll see these in a future post), and then spent some time staking out larval burrows for attempted photographs.  We ended up spending a couple of hours at the site without seeing anything remarkable, but by then it was early afternoon and there was little point in trying to find another locality to search – it was a gorgeous spot on a gorgeous day, and just being out there was almost reward enough.  (I’m guessing by now you see where this is going…)

Cicindela lengi - blowout tiger beetle

As I began my umpteenth pass along the lower stretch of the embankment, I heard Chris call out, “I’ve got it!”  Chris hadn’t previously seen this species, so I fully expected when I walked over to where he was standing that I would find instead the much more common and amazingly similar C. formosa.  However, when I spotted the adult as he pointed to it, there was no doubt – the longer, obliquely straight humeral lunule (shoulder marking), the slightly more cylindrical, parallel-sided body, the more extensive brilliant green marginal highlights on the head and pronotum – it was, indeed, C. lengi!  The close resemblance of C. lengi to C. formosa is not the result of a close relationship, but rather an example of convergent evolution in response to similar habitat.  Cicindela lengi is actually more closely related to C. tranquebarica (oblique-lined tiger beetle) and other species formerly placed in the now defunct subgenus Tribonia.  As the first finder, Chris had first photo honors as well while I stood back, ready with the net should it spook and become uncooperative.  It did make a few short escape flights at first, but as I’ve learned before this species tends to make very short, weak flights before dropping straight down, making it rather easy to follow even on the steep embankment that we found ourselves.  This contrasts with C. formosa, whose long, powerful escape flights and bouncing tumbles upon landing can make them difficult to follow.  Eventually it became accustomed to our presence, and after Chris was satisfied with his photographs it was my turn.  We then we took turns again just to make sure we really got the shots we wanted.

Cicindela lengi - note the obliquely straight humeral lunule and relatively narrow, parallel-sided body.

It’s a good thing we didn’t pull the plug on Monroe Canyon that day, as tiger beetle activity really picked up during the afternoon hours.  Not only did we end up seeing several individuals of C. lengi during the next couple of hours, but also a few individuals of C. formosa and C. scutellaris and a single, seemingly misplaced Cicindela denverensis (green claybank tiger beetle), more fond of clay substrates than sand) – making Monroe Canyon a veritable “hot spot” of tiger beetle diversity.  While Monroe Canyon may not equal Willcox Playa, Laguna del Perro, Salt Plains National Wildlife Refuge, or Florida’s Road to Nowhere, six species is still a respectable amount of diversity by any measure, especially for a dry, upland site (all of the other sites mentioned are lowland saline habitats that owe their tiger beetle diversity at least in part to their broad range of available moisture zones).  After two days in the field, our trip total now stood at ten species, and in retrospect we were lucky to see C. lengi when we did as our subsequent search of the C. lengi spot 4 miles east of Harrison later that day turned up nothing.

Brilliant green highlights contrast spectacularly with the red body and bold white markings.

Copyright © Ted C. MacRae 2010

Posted in Cicindelidae, Coleoptera | Tagged , , , , , , , | 16 Comments

Answer to Super Crop Challenge #2

Posted on December 5, 2010 by Ted C. MacRae

I was hoping that Super Crop Challenge #2 would prove a little more difficult than the first one, but first responder Troy Bartlett quickly sniffed out the correct answer – the top part of the abdomen of the marmorated orb weaver, Araneus marmoreus.  As the first correct responder he earns bonus points.  Dennis also came up with the same answer after temporarily being led astray, and Colton got it right as well (once he realized the challenge was here and not over on FaceBook).  I might be justified if I deducted points for misspellings in the genus and common names (if there is any field unforgiving of spelling errors, it’s taxonomy); however, I’m watching a Christmas movie with my family and am feeling the holiday spirit.  That spirit extends to Dave as well, who earns pity points for refusing to believe that I would offer consecutive spider challenges (actually the first Super Crop Challenge was an opilionid, but the ID challenge before that was another spider, making this the third straight arachnid challenge I’ve posted – it wasn’t by design).

The crop I used for this challenge was taken from the above photo – not the best of the series, but it had the most symmetrical view of the dorsal abdominal pattern that some think looks like a face.  This is just one of many color variations exhibited by this most variable of North American spiders – see this BugGuide page for a pictorial summary of the extraordinary amount of variation found in this species.

My friend Rich and I encountered this individual – a female – in an upland oak/hickory forest while hiking the lower North Fork Section of the Ozark Trail in extreme southern Missouri.  These spiders normally hide in a retreat during the day (usually a curled leaf) and spin a new web at night – I’m not sure why she was out during the day, as it didn’t appear she was recycling the web, tattered and torn and probably still remaining from the previous evening.  When I first approached, I accidentally brushed against one of the support lines, which sent her scampering up into her retreat.  I figured “tapping” on the leaf might cause her to drop back out – Rich was skeptical, but after a few taps, the spider not only dropped out but obligingly went right back down to the center of the web and stayed in place long enough for me to get a few shots of the ventral surface.  (I couldn’t suppress a smug chuckle as Rich muttered in exasperated disbelief!)  Moving around to the other side disturbed the spider again, and she once again took refuge in her retreat.  This time, rather than fight it, I carefully uncurled the leaf that formed her retreat, working gingerly to avoid disturbing her, and took a series of photos of her attractive dorsal surface as she sat in the retreat.

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/200 sec, f/16), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask, etc.).

Copyright © Ted C. MacRae 2010

Posted in Arachnida, Araneae | Tagged , , , , , | 8 Comments