Cicindelidae

Tiger beetles. Adults are agile predators in open areas such as stream banks and beaches; a few species are wingless and on tree trunks. Larvae are ambush predators living in vertical tunnels of soil or wood.

ESA in absentia

/ Ted C. MacRae / 6 Comments

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

Cleaning Tiger Beetles

/ Ted C. MacRae / 22 Comments

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

Monroe Canyon – A Tiger Beetle “Hot Spot”

/ Ted C. MacRae / 16 Comments

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

Kirby’s Tiger Beetle

/ Ted C. MacRae / 23 Comments

Dry alkaline creek in the Oglala National Grasslands, Sioux Co., Nebraska

At the northern edge of the Pine Ridge in northwestern Nebraska, the land drops precipitously from verdant High Plains to the eerie Badlands below.  The sterile landscape of eroded slopes and irregularly shaped landforms is at once beautiful and harsh.  Short grasses and silver sagebrush seem to be the only plants capable of living here, providing the meagerest of forage for the mule deer and pronghorn antelopes that dot the gently rolling hills.  Dissecting these arid grasslands are a series of seasonally dry alkaline creeks that support a number of tiger beetle species.  The most interesting of these is Cicindela fulgida fulgida (crimson saltflat tiger beetle), a beautifully colored little species that is restricted to wet, alkaline habitats.  It was this species that I and colleagues Chris Brown and Matt Brust wanted to see when we stopped by one such creek after finishing up at the C. pulchra site in South Dakota (and still recovering from “pulchra-fever”).

Cicindela tranquebarica kirbyi - Kirby's tiger beetle

I had been to this spot two years before and encountered a small number of C. fulgida along with much higher numbers of C. purpurea audubonii (Audubon’s tiger beetle) and C. tranquebarica kirbyi (Kirby’s tiger beetle).  Our luck wasn’t any better this time, and in fact we would encounter only a single C. fulgida that day.  This was Chris’ first opportunity to photograph this species, while I had already gotten some reasonably good field photos of the species during my 2009 visit to Salt Plains National Wildlife Refuge in northwestern Oklahoma.  As he photographed the individual, I continuing scanning the bright, alkaline barrens.  While I was not finding any C. fulgida, I was seeing a fair number of C. tranquebarica kirbyi, and it occurred to me that I still lacked good field photographs of this species.  I began stalking different individuals, but in the heat of the day I found it impossible to get close enough to any of them to attempt any shots.  It wasn’t until I encountered the individual shown above, apparently dragging something from its rear end, that I was able to close in for some shots.  A closer look revealed the individual to be a male who had somehow gotten his genital capsule pulled out of his abdomen.  Just the thought of how this might have happened makes me cringe.  At any rate, the individual exhibits the relatively broader white maculations that distinguish this Great Plains/Rocky Mountain subspecies from the more eastern nominotypical subspecies.

A newly emerged Kirby's tiger beetle sits at the entrance of his burrow.

As I continued scanning the soil, I noticed a number of larval burrows of what I took to be this species located up near the edge of the vegetated zone.  One burrow in particular caught my attention – partly because of its slightly larger size and irregular outline, but also because there appeared to be something sitting within it.  A closer look revealed an adult tiger beetle sitting just below the burrow entrance.  Cicindela tranquebarica is a so-called “spring-fall” species that emerges initially in the fall as a sexually immature adult before digging back in for the winter and re-emerging in spring for mating and oviposition.  I thus took this individual to be a newly emerged male that had not yet decided to leave its burrow and burst forth into a life of adulthood.  The opportunity couldn’t be passed up – I took a few photos of him sitting there, then switched out the 100mm lens for the 65mm 1-5X lens.  I had to get real close for this last shot, which caused him to retreat somewhat in his burrow.  However, a knife thrust into the burrow below him, followed by careful twisting until it touched his rear, caused him to return to the burrow entrance and once again pause before embracing his new world.

A male Kirby's tiger beetle prepares to leave his emergence burrow.

Copyright © Ted C. MacRae 2010

Cicindela pulchra on white

/ Ted C. MacRae / 16 Comments

Two more photographs taken with my new diffuser, this time the spectacular Cicindela pulchra (beautiful tiger beetle). Which one do you like better?

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/16), Canon MT-24EX flash w/ oversized concave diffuser. Standard post-processing (levels, unsharp mask).

Copyright © Ted C. MacRae 2010

Amblycheila cylindriformis on white

/ Ted C. MacRae / 37 Comments

It’s been four months now since I went to the Glass Mountains of northwestern Oklahoma on a hunch to look for Amblycheila cylindriformis (Great Plains giant tiger beetle).  The five adults that I brought back from that night are still alive in a terrarium of native soil, but to this point they have refused to lay eggs.  Despite feeding them regularly with fat Maduca larvae, there is obviously still something they need that I am not providing.  I’ve suspected that perhaps the terrarium that I have them in is too small, and I’ve also noted in the literature that larval burrows are often found clustered near the entrance of mammal burrows.  With this in mind, I combined the native soil from three separate terraria into one larger, deeper terrarium, packed the soil lightly, and used a spoon to create an artificial mammal burrow entrance.  Not long after placing the adults in their new home they began digging at the back of the burrow, eventually creating two separate tunnels leading in opposite directions (and fortunately against the container walls so that I can see inside the tunnels).  I was optimistic at first that finally I had given them what they wanted, but since digging the burrows they’ve just sat in them.  Perhaps they “know” that winter is coming and are just looking to hole up for now, so I suppose I’ll go ahead and place the terrarium in the 10°C incubator with the rest of my larval and adult rearing containers and wait until next spring to see what happens.

In the meantime, I thought I would share these recent photographs of one of them.  I had been wanting to take photographs of this species in a white box, which I have used with a few other species to generate some rather striking photographs (e.g., Gromphadorina portentosa, Buprestis rufipes, Scolopendron heros, Eleodes suturalis). The photographs in this post might look like they were taken in a white box, however, they were not.  I’ve been spending a lot of time lately trying to come up with a diffuser setup that is convenient for field photographs of wild insects in their native habitats.  Kurt’s do-it-yourself concave diffuser and Alex’s tracing paper diffuser work great with the Canon MT-24EX Macro Twin Lite Flash and the Canon MP-E 65mm f/2.8 1-5X Macro Lens, but as I mentioned in a previous post they do not work so well with the Canon EF 100mm f/2.8 Macro USM Lens and its longer working distance… or so I thought!  I’ve come up with a modified version of the concave diffuser that seems to be what I am looking for – it is easy to use, adds virtually no weight to the camera, is completely portable for field use, can be used with both the 65mm and 100mm macro lenses, and – best of all – costs virtually nothing.  The photographs in this post were taken with the first prototype, and now that the basic design and general dimensions seem to work I’ll try to make a more durable version. It’s simply a larger version of the concave diffuser – I found some very thick polypropylene foam that is sturdy enough to hold its shape but flexible enough to curl back and over the top of the flash heads, where the corners are held in place by Velcro. Essentially it forms a large “soft box” type diffuser in front of both flash heads. I cut the bottom inch off of a a 500-mL polypropylene beaker, then cut that in half and cut out all but a quarter inch of the bottom to form a sturdy but transluscent frame to hold the polypropylene foam against the flash head bracket on the front of the lens. Right now the foam is held in place by tape, but hot glue should do a better job, and the diffuser bracket is attached to the flash head bracket with Velcro. The whole rig comes off in a flash and lays mostly flat in the camera bag.

If this diffuser proves successful, it will eliminate the need for the different flash head extender brackets that I was considering.  I really didn’t want to go that route because even the cheapest models are rather costly, and all of them add bulk to the camera and create problems for those who need to switch lenses frequently (such as I do).  Of course, the real test is – does it achieve the desired result?  I’m quite happy with these initial photographs – the lighting is quite even due to the large “apparent” size of the light source, and the annoying double specular highlights that are the hallmark of the MT-24EX are much less apparent (though still slightly discernible).  The closest shots are at 1:1, while those of the entire beetle are between 1:1.5 and 1:2.  They are among the largest beetle species that I have photographed, so the range of magnifications used here pretty much covers the entire range that I typically use with this lens.  Wildflowers often require smaller mags and longer working distances, so it remains to be seen whether this diffuser/lens combination will be useful for them as well. 

All of the photographs in this post were taken with the 100mm macro lens (ISO100, 1/250 sec, F16) and direct MT-24EX macro twin flash using this new diffuser.  The beetle was placed on white filter paper and covered with a clear glass bowl until it settled against the side of it.  Once the beetle was quiet, I gently lifted the bowl and used micro-forceps to gently tug its legs into more appealing positions – surprisingly this did not cause it to become alarmed and try to flee (as long as I didn’t accidentally brush against one of its antennae!).  For the last photograph, I placed the beetle back in its terrarium and used the same techniques to get the beetle in a good position. 

Copyright © Ted C. MacRae 2010

Cicindela nebraskana – Prairie Long-lipped Tiger Beetle

/ Ted C. MacRae / 14 Comments

Cicindela nebraskana - the prairie long-lipped tiger beetle

We were only halfway through Day #1 of five days in the field and had already achieved Goal #1 of the trip.  Despite that, it took a few hours before Chris and I were ready to tear ourselves away from our first stop in Fall River Co., South Dakota, where we were treated to the sight of glittering, wine-red adults of Cicindela pulchra bejeweling the charcoal-colored shale slopes.  However, the list of species that we wanted to see over the next several days was long, and eventually our pulchra-fever abated (barely) enough to head south to the Pine Ridge in Sioux Co., Nebraska to look for A-list Species #2 – Cicindela nebraskana.  Sioux Co., Nebraska is the type locality for this species (thus the name), but in reality it is a more western species whose distribution just barely sneaks into the northwestern corner of Nebraska (Pearson et al. 2006, Spomer et al. 2008).  I first saw this species at this very site two years ago, seeing only a handful of individuals and managing one harshly-sunlit, point-and-shoot image of one of them.  To my knowledge, this remains the only known field photograph of this species.

Shortgrass prairie atop the Pine Ridge, Sioux Co., Nebraska (photo taken September 2008).

This time, with a Canon 50D camera and 100mm macro lens in my backpack, I was much better equipped for vastly improved field photographs, but in contrast to the numerous individuals of C. pulchra that we saw earlier in the day, only a single C. nebraskana would turn up after intensive searching by Chris, Matt Brust, and myself in the vast shortgrass prairie sitting at the type locality atop the Pine Ridge.  I didn’t find it – Matt did – and the general rule with rare tigers is to capture the first individual rather than try to photograph it.  If no others are seen, photographing it later in a terrarium of native soil is better than trying to photograph it in the field and risk letting it escape.  Matt gave it to Chris, and at the end of the day when we realized we were not going to see another one, we prepared a terrarium of native soil, taking care to keep the surface as intact as possible so that an accurate replication of the field situation could be created when we photographed it later.

Tiger beetles "hunker down" when fatigued.

Although I prefer actual field photographs, the nice thing about photographing tiger beetles in confinement is… well, they don’t run away!  That’s not to say it is easy.  While they do settle down if left undisturbed for a while, once you start messing with them they quickly become agitated and start running in circles around the terrarium perimeter.  Much finger prodding is necessary to get them away from the edge and into a good spot for photographs, and rarely do they stay put for long.  When they finally do settle down, they tend to “hunker down” in a most unflattering pose (as above) – lacking the appearance of alertness that gives the true field photos their life.

A ferocious pose is struck after judicious prodding of the face and touching of the antennae.

I’m a persistent (syn. stubborn) sort, however, and I’ve learned that I can wear them down and poke and prod them out of their hunker.  Just a light poke at the face will often make them back up and lift their front slightly – poke again and they often open their jaws half-cocked – a light touch on the tip of one antennae and they’ll turn slightly.  With practice and patience, hunkered down beetles can be coaxed into some remarkably aggressive-looking poses.  I like the last of these photos in particular because the oblique, jaws half-cocked pose shows off two nice features of this species – the quite long labrum (upper lip) compared to most other tiger beetle species, and the bright white labrum and mandibles of the males of this species (in females they are partially or completely dark).  The long labrum and jaws give this species a very long-faced appearance that distinguishes it immediately from the black morphs of Cicindela purpurea audubonii that occur with much greater frequency in the same habitats as C. nebraskana.

Photo Details:
1: Canon 50D w/ MP-E 65mm 1-5X macro lens (ISO 100, 1/250 sec, f/13), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers.
2: Panasonic DMC-FX3 (ISO 100, 1/400 sec, f/5.6), natural light.
3-4: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/16), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers.
All photos: Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

Spomer, S. M., M. L. Brust, D. C. Backlund and S. Weins.  2008. Tiger Beetles of South Dakota & Nebraska.University of Nebraska, Department of Entomology, Lincoln, 60 pp.

Copyright © Ted C. MacRae 2010

Flash solutions for the beautiful tiger beetle

/ Ted C. MacRae / 27 Comments

Canon MP-E 65mm f/2.8 1-5X macro lens (f/13), Canon MT-24EX flash w/ concave diffuser.

Recently I’ve been trying some different lighting and flash diffusion techniques with the Cicindela pulchra adults I brought back from South Dakota (see previous post).  While the beetles themselves are certainly among the most spectacular tiger beetles I’ve ever seen, I’ve been less than impressed with the photographs that I’ve managed to take of them.  Two factors have been largely responsible for this: 1) the smooth, shiny integument of the beetle reflecting the flash to create strong specular highlights, and 2) the colors, though brilliant, are also dark and difficult to bring out without further exacerbating the specular highlights.  Normally, the Sto-Fen+Puffer diffuser combination that I use does a pretty good job at diffusing the flash, but it just can’t handle these beetles.  To deal with this problem, I finally got around to trying out the do-it-yourself concave diffuser that Kurt at Up Close with Nature has been using with stunning results (similar to the tracing paper diffuser used so famously by Alex Wild at Myrmecos).  Photo 1 above and 2-3 below were taken with this diffuser on my Canon MP-E 65mm f/2.8 1-5X Macro Lens, and I’m rather pleased with these initial attempts.  I do need to figure out a better way to attach the diffuser to my Canon MT-24EX Macro Twin Lite Flash.

Canon MP-E 65mm f/2.8 1-5X macro lens (f/13), Canon MT-24EX flash w/ concave diffuser.

Canon MP-E 65mm f/2.8 1-5X macro lens (f/13), Canon MT-24EX flash w/ concave diffuser.

I’d have to say the lighting with this diffuser represents a considerable improvement over the Sto-Fen+Puffer diffusers using the same lens.  Compare especially Photo 3 above and 4 below – both taken with the MP-E 65mm lens at 1:1 and f/13 – Photo 3 was taken using the concave diffuser, while Photo 4 used the Sto-Fen+Puffer diffusers.

Canon MP-E 65mm f/2.8 1-5X macro lens (f/13), Canon MT-24EX flash w/ Sto-Fen+Puffer diffusers.

The problem with the concave diffuser is that it won’t work so well on my Canon EF 100mm f/2.8 Macro USM Lens due to its longer working distance.  I actually use this lens in the field as often as the MP-E 65mm lens, especially for the tiger beetles on which I focus (heh!) – not only do they rarely require more than 1:1 magnification, but they also rarely allow the ultra-close approach needed to use the 65mm lens.  The only solution is to find some way to get the flash heads closer to the subject to increase the apparent size of the light source, but so far I haven’t figured out a satisfactory way to do this.  Some photographers use the stalwart Canon Speedlite 580EX II Flash, equipped either with a do-it-yourself snoot diffuser or mounted on a bracket extender with a small softbox.  However, I am not a photographer, but rather an entomologist with a camera – I need to carry with me a net, vials, and in some cases a beating sheet and hatchet.  Both of the previously mentioned approaches for diffusing 100mm shots add far more bulk to the camera setup than I can accept.  I’ve been looking for extender brackets that will move the MT-24EX flash heads out closer to the subject to increase apparent light size and have found a few.  The Really Right Stuff B85-B Flash Bracket equipped with two FA-EX1 Flash Extenders and an extra Flash Mount looks like it would do the job quite well, but it is still bulkier (and vastly more expensive) than I would like.  The PhotoMed R2-C Dual Point Flash Bracket is a much less bulky and more reasonably priced option; however, the lack of any vertical adjustment capabilities is an insurmountable shortcoming.  Why Canon hasn’t themselves designed a lightweight, low-cost accessory for extending the MT-24EX flash heads out away from the lens is beyond me, and I’ve actually been toying with some ideas on how to do this myself using a couple of Kaiser Adjustable Flash Shoes.

Until I do figure out a solution, at least there is always the white box for any captive-held individuals (and yes, I have considered a small, collapsible white box to bring into the field – I’m not ready to resort to that just yet!):

Canon 100mm macro lens (f/16), Canon MT-24EX flash indirect in white box.

Photo Details: Canon 50D (ISO 100, 1/250 sec). Typical post-processing (levels, minor cropping, unsharp mask).

Copyright Ted C. MacRae 2010