beetles

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

North America’s most beautiful tiger beetle

/ Ted C. MacRae / 18 Comments

Cicindela pulchra pulchra (beautiful tiger beetle) - Fall River Co., South Dakota.

Five years ago this month, I got my first glimpse of North America’s most beautiful tiger – Cicindela pulchra.  This is not just my opinion – its name, given to it by Father-of-North-American-entomology Thomas Say, literally translates to “beautiful tiger beetle.”  Like Amblycheila cylindriformis, it was a species that I longed to see in the field ever since receiving a single specimen from tiger beetle guru Ron Huber.  That specimen came from the Gypsum Hills of Barber Co. in south-central Kansas – a known “hot spot” for the species.  For years I stared at that spectacular specimen as it sat in my cabinet, and in September 2004 Chris Brown and I finally made our first attempt to see it in the field for ourselves.  Unfortunately, we arrived ahead of the fall rains that seem to trigger emergence of this species, and C. pulchra would not be among the few species that we saw on that trip.  I don’t handle defeat very well, so the very next fall I resolved to try again – this time waiting until early October and also enlisting the assistance of local entomologist “Beetle Bill” Smith for access to better sites than what are available along the roadsides.  That trip was a tremendous success and was detailed in one of my Nature Notes articles (MacRae 2006), but Chris, unfortunately, was unable to join me on that second attempt.  He couldn’t join me last year, either, for my search of the species in the nearby Cimarron Gypsum Hills of northwestern Oklahoma.  Good thing, however, as a turn of the weather left me just cold and wet (although I do remain convinced that the species will eventually be found on those red clay slopes that have so far produced such prizes as Cylindera celeripes, Dromochorus pruinina, and Amblycheila cylindriformis).

Matt Brust (L) and Chris Brown (R). Matt discovered this site for Cicindela pulchra in 2009.

Fortunately, while I was getting skunked in Oklahoma, Matt Brust was discovering new populations of the species further north in the southwestern corner of South Dakota.  These discoveries were prompted by the initial discovery of the species on Pierre Shale exposures at a single site near the Black Hills (Larsen and Willis 2008).  The soft, dark gray soils of the Pierre Shales are in distinct contrast to red clay exposures with which the species has been typically associated further south, and by scouting a broader area for similar exposures Matt was able to find the species at six new sites during late summer 2009 (Brust 2010).  He found them associated not only with the Pierre Shale but also the Mowry Shale formation (and suspects they may eventually be found on Belle Fourche Shale formations as well).  When I learned of these discoveries, I decided I just had to see them for myself.  I had enjoyed my Fall 2008 trip to northwestern Nebraska and southwestern South Dakota, and the thought of seeing these beetles while spending time in the field with Matt once again seemed the perfect basis for another trip to the area.  It didn’t take much convincing for Chris to agree, thus, C. pulchra became goal #1 of the 2010 Fall Tiger Beetle Trip™.

Habitat for Cicindela pulchra in Fall River Co., South Dakota. Adults and larval burrows are found in sparsely vegetated gray shale slopes and open flats beneath.

As we drove to the site that Matt had selected for us to explore, I felt nothing but optimism.  The skies were clear and the temperature was already nearing 70°F.  Matt, however, was hedging his bets – “I hope they’re still out, I’ve never seen them this late!”  Still, I wasn’t worried.  We were two weeks earlier in the season than the 2005 Kansas trip, and the weather was simply spectacular – it just had to be a good tiger beetle day!  My optimism was justified, as within minutes of arriving at the site we saw the first individual.  I collected this one alive as a backup for photographs in the studio should that be the last one we saw, but no such contingencies were necessary – we began seeing individual after individual as we trolled across the barren gray slopes.

Adult male Cicindela pulchra taking in the morning sun.

These beetles are simply a marvel to see in the field.  Brilliant dark red with metallic green, blue, and purple borders on the head, thorax, and elytra, this relatively large tiger beetle (certainly among the largest in the genus) can be confused with no other tiger beetle in North America.  Unlike adults of most other species, which exhibit color patterns resembling the texture and hue of the soil substrate on which they occur, C. pulchra adults are obvious and non-cryptic.  It apparently mimics the large, similarly colored velvet ants of the genus Dasymutilla with which they are sympatric – even exhibiting similar behavior when alarmed such as stridulating (creating vibrations by scraping body parts across one another) and giving off defense chemicals (Pearson 1988).  Adults are powerful fliers that can fly long distances when alarmed (Spomer et al. 2008), but in the still relatively cool morning air Chris and I had relatively (emphasis on relatively!) little trouble getting close enough to attempt those coveted field photographs.  This, however, was a double-edged sword – the same cool temperatures that allowed us to get close enough for photographs also caused to the beetles to assume the most non-photogenic poses as they sprawled torpidly on the ground, sometimes hugging it closely in an attempt to conserve heat until incident radiation from the sun warmed them sufficiently to go about the day’s activities.  Once this did happen, we found getting close enough for photographs nearly impossible.  In the 2+ hours that we chased after them, we took many shots but failed to get that “perfect” shot of a brilliant beetle standing tall and alert.

Adult male Cicindela pulchra hugs the ground during the cool morning hours.

Cicindela pulchra is a “spring/fall” species – i.e., sexually immature adults emerge during fall to feed, then return to their burrows to overwinter before emerging again in spring to mate and lay eggs.   Pearson et al. (2006) state the fall period lasts from July to September; however, as I observed in Kansas in 2005 adults can remain active well into October as long as suitable weather prevails.  Larvae hatch shortly after eggs are laid in the spring, but larval burrows can be seen during the entire season since they require 2-3 to complete development.  It was actually the presence of the large larval burrows (see photo below) that alerted Matt to the occurrence of the species at this site.  Several other tiger beetle species are also found here, e.g. C. purpurea (cow path tiger beetle) and C. tranquebarica (oblique-lined tiger beetle); however, these species – and hence their larval burrows – are considerably smaller than C. pulchra.  The only other species of Cicindela in North America that matches C. pulchra in size is C. obsoleta (large grassland tiger beetle), a southwestern species that is not known to range as far north as Nebraska and South Dakota, and the slightly smaller C. formosa (big sand tiger beetle) larval burrow has a distinctive “pitfall trap” with the burrow opening situated horizontally above it (it is also restricted to dry sand rather than clay habitats).  We saw several C. pulchra larval burrows during our visit but no active larvae, and none of my attempts to “fish” them out of their relatively shallow burrows met with success.  I could have tried digging them out, but that is a time-intensive activity, and I decided instead to bring a few live adults back in a terrarium of native soil and see if I could rear the species from egg.

Despite the presence of at least two other tiger beetle species at the site, this can only be that of a 3rd-instar Cicindela pulchra due to its large size.

I had tried persistently during the last hour we were there to get a good field photograph of an active adult beetle standing tall and alert, but the following is the closest I was able to achieve.  Leaving the site without that “perfect” shot was difficult – as Matt put it, we had “pulchra fever”!  Still, there were other tiger beetles – e.g. C. nebraskana (prairie long-lipped tiger beetle) and C. decemnotata (badlands tiger beetle) – that we wanted to find in the limited time we had to explore the region, so I prepared a terrarium for the live adults I was bringing back with me and chalked up our first big success of the trip as we headed towards the shortgrass prairie sitting atop the nearby Nebraska Pine Ridge.

I chased this adult female for some time trying to get a closer photograph, but warming temperatures made this impossible.

In addition to attempting to rear the species,  bringing live adults back with me also gave me more opportunity to photograph them.  In addition to the native crumbly shale soil that I used to fill the terrarium, I placed in it one of the nicely colored, presumably volcanic, rocks that littered the slopes on which the beetles occurred.  The dark color of the rock makes a nice backdrop to really show off the extraordinary colors of this species – especially the bright white labrum and mandibles of the particularly impressive male in the following photograph.  The beetles are all now sound asleep for the winter in a 10°C incubator.  Hopefully, when I move the terrarium back into warm temperatures next spring they will re-emerge, mate, and lay eggs (hmm, photographs of a mating pair would be really nice!).

The all-white labrum and mandibles of this male Cicindela pulchra are displayed nicely in this terrarium photograph.

Photo Details:
Insects: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/16), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers.
Habitat: Canon 50D w/ 17-85mm wide-angle lens (ISO 100, 1/160 sec, f/11), natural light.
Matt and Chris: Canon 50D w/ 17-85mm wide-angle lens (ISO 100, 1/250 sec, f/11), natural light.
All photos w/ typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Brust, M. L.  2010. New distribution records for Cicindela pulchra pulchra Say in South Dakota and notes on habitat use and natural history.  Cicindela 42:1–10.

Larsen, K. J. and H. L. Willis.  2008. Range extension into South Dakota for Cicindela pulchra (Coleoptera: Carabidae).  The Coleopterists Bulletin 62(4):480.

MacRae, T. C. 2006. Beetle bits: The “beautiful tiger beetle”. Nature Notes, Journal of the Webster Groves Nature Study Society 78(4):9–12.

Pearson, D. L.  1988. Biology of tiger beetles.  Annual Review of Entomology 33:123–147.

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

Missouri’s disjunct population of Cicindela obsoleta vulturina

/ Ted C. MacRae / 18 Comments

Although I’ve been collecting insects since I was a kid (and seriously for nearly three decades), it has only been in more recent years that fall has become an important part of the collecting season for me. With the notable exception of Fall 1978, when the Systematic Entomology course I was enrolled in sent me on a frantic quest to become one of the few undergraduate members of the exclusive “200 family” club (I got 205!), I long viewed fall as a time to hang up the net and begin the winter-long process of mounting, labeling, and curating the hundreds – sometimes thousands – of specimens I had collected earlier in the year during spring and summer.  This has primarily been a reflection of my taxonomic interest – woodboring beetles in the families Buprestidae and Cerambycidae, which occur at their overwhelmingly greatest abundance and diversity throughout most of North America during spring and summer but are found only sparingly later in the season.  Tiger beetles (family Cicindelidae) changed all that, and when I first began serious study of the group around 10 years ago, I found the combination of gorgeous weather and multitude of “spring/fall” species that emerge briefly during fall an irresistible siren call to the field. I’ve not looked back, and the Annual Fall Tiger Beetle Collecting Trip™ is now an established and eagerly anticipated event.

Cicindela obsoleta vulturina - the prairie tiger beetle (Blackjack Knob, Taney Co., Missouri).

No species embodies all that I love about fall tiger beetle collecting more than Cicindela obsoleta vulturina, the prairie tiger beetle. I first learned of the occurrence in Missouri of this large, dark green species back in 2000, when I saw a single specimen in the Enns Entomology Museum collected in Protem, Taney Co.  I was just beginning my tiger beetle studies and would later learn what the Tiger Beetle Guild already knew – that the occurrence of this species in Missouri was restricted to cedar glade habitats in the White River Hills region in the extreme southwestern part of the state, and that the population occurring there and in adjacent northern Arkansas was disjunct by 300+ miles from the main population in Texas and Oklahoma.  I couldn’t wait to see it for myself and eventually enlisted the help of Eric Eaton, living in the area at the time, and asked him to let me know if he saw a large green tiger beetle after the late summer rains began.  That September, I got a message from Eric saying that he had seen just such a beast not far from his home, and the following weekend he and I would enjoy the chance to meet each other in person and the splendor of the season while finding this marvelous species at several locations in the area.  Thus began my love affair with this species, and for several years I returned to the area each fall to document additional localities for this and other tiger beetle species occurring in the area.

Blackjack Knob is part of an extensive xeric dolomite prairie complex (commonly referred to as cedar glades, though the term is not precisely accurate) in the White River Hills subsection of the Ozark Highlands, providing habitat for prairie tiger beetles and other typically southwestern plants and animals.

In fact, until a few weeks ago it had been several years since I had last seen this species in the field.  I did make an attempt to see it again last year but returned home from that early October trip unsuccessful, cold and wet.  Thus, when tiger beetle enthusiast Steve Spomer mentioned to me earlier this summer that he wanted to see our Missouri population, I jumped at the chance to coordinate our visits this fall and show him some of my favorite sites.  The Patron Saint of Cicindela was smiling down upon us that day, as perfect timing and sunny skies combined to bring adults out in an abundance that I’d not seen in any of my previous visits.  I would take advantage of this rare opportunity and spend the next day in the area as well, documenting a number of new localities along the northern and eastern edge of its known distribution, including a far eastern extension of its range to Caney Mountain Conservation Area in Ozark Co. where we had long suspected the beetle to occur but failed in all previous attempts to find it.

Steve Spomer and yours truly at Cane Creek Rd. site.

The prairie tiger beetle is the easternmost subspecies of the large grassland tiger beetle, which along with its other included subspecies covers a geographic range covering most of Texas, New Mexico, and eastern Arizona and extending up through western Oklahoma and Kansas into eastern Colorado.  Individuals of subspecies vulturina, occurring primarily in eastern/central Texas, are distinguished from the other subspecies (nominate in western Texas and eastern New Mexico north into Colorado, santaclarae in New Mexico and Arizona, and neojuvenilis in south Texas) by their generally black to olive-green coloration and reduced, narrow elytral markings, typically with an inverted “V” at mid-elytron.  The Missouri/Arkansas disjunct population is interesting from several standpoints:

  • Individuals mostly dark olive-green – no black individuals.
  • Elytral maculations more completely developed.
  • Adults active in late summer/early fall rather than summer.

These features, in particular coloration and maculation, have fueled speculation that this isolated population might be subspecifically distinct (Pearson et al. 2006).  A recent review of material from throughout its range found these color characters of limited use in unequivocally diagnosing individuals from the Missouri and Arkansas population as a separate subspecific taxon (Mawdsley 2009); however, a molecular systematics approach ultimately may be needed to resolve the status of this population.  Presumably, the Missouri/Arkansas disjunct population represents a hypsithermal relict, left behind when the return of cooler, moister conditions caused a retreat of the formerly more expansive grasslands to their current position.  If true, then the Missouri/Arkansas population has been isolated from the parent population for ~6,000 years.  I suspect that the late summer/early fall adult phenology is an adaptation to local precipitation patterns, relying on more predictable late summer rains to trigger adult emergence after the generally droughty months of July and August.  In this regard it differs fundamentally from the true “fall” species, which emerge briefly in the fall as sexually immature adults before overwintering and re-emerging in the spring for mating and oviposition.  These Missouri/Arkansas disjuncts do not re-emerge in spring, but instead mate and lay eggs in the fall before the onset of cold weather.  The eggs hatch as well (based on my growth chamber observations of this species), so winter also is passed as a larva – either as newly-hatched 1st instars, or as later instars that hatched during the previous year(s) – rather than as adults.

I have noted considerable variation in the coloration and maculations of individuals in this population.  The individual in the first photograph above is typical of the population – dark olive-green with thin but nearly complete maculations.  That individual comes from Blackjack Knob (Taney Co.), which is near the heart of the White River Hills region.  However, the degree to which the maculations are developed is variable, ranging from rather incomplete to even more fully developed due to the presence of a marginal connection.  Additionally, a few individuals can be found that show greater or lesser suffusion of brown on the head, pronotum, and elytra.  At another location in the county closer to the northern distributional limit (Hwy 160/Cane Creek Rd.), this brown suffusion is more common and variably expressed from minimal to nearly complete.  The photographs below show five individuals from this site expressing differing degrees of brown as well as the variable macular development seen throughout the population:

Male (Hwy 160/Cane Creek Rd.) - green w/ trace brown, marginal band incomplete, median band complete.


Female (Hwy 160/Cane Creek Rd.) - green w/ slight brown, marginal band complete, median band incomplete.


Male (Hwy 160/Cane Creek Rd.) - green w/ moderate brown, marginal band incomplete, median band incomplete.


Male (Hwy 160/Cane Creek Rd.) - green w/ heavy brown, marginal band complete, median band complete.


Female (Hwy 160/Cane Creek Rd.) - completely brown, marginal band complete, median band incomplete.

There is another site even further north in the county (Merriam Woods), which I found for the first time on this trip and, to my knowledge, represents the northernmost extent of the population in Missouri.  At this site, nearly all of the individuals show coppery-brown coloration with almost no hint of green.  These fully brown individuals seem to represent an appearance that is completely unlike that seen in any other part of the range of the species.  The individual in the photo below typifies the appearance of the beetles seen at this site:

Male (Merriam Woods) - brown, marginal band incomplete, median band complete.

I’m less familiar with coloration of the population further south in Arkansas, although in my limited collecting in that area I recall that most individuals I encountered exhibited the dark olive-green coloration typical of individuals at Blackjack Knob and other more southern sites in Missouri.  Thus, there seems to a clinal element to variability in coloration in the Missouri/Arkansas disjunct population.  I suspect that the unique coloration of the beetles in this population is related to the soils with which they are associated.  Light gray Jefferson City-Cotter dolomite bedrock forms the core of the White River Hills landscape and is exposed extensively in the glades that dominate its knobs and slopes.  These exposures are weather-stained black and overlain by thin, black soils that support dark, green-black lichens amongst the sparse vegetation, as seen in the following photographs taken at the newly identified northeasternmost site at Caney Mountain Conservation Area:

Thinly soiled dolomite exposures punctuate the glades in the White River Hills. Prairie tiger beetles are found in these exposures.


Dark green-black lichens encrust the thin black soils overlaying the dolomite exposures. Prairie tiger beetle adult coloration closely matches the coloration of the lichens and soil.

The glades and dolomite exposures where these beetles are found in the White River Hills and the dry oak woodlands that surround them have a characteristic look that is not seen once one leaves the area, and I have found many new sites for the beetle in the northern and eastern fringes of the region by stopping at locations where the roadside exposures had the right “look.”  The variation in maculation and coloration seen in this population may be an indication that the population is still adapting to local conditions since becoming isolated from main population.

Currently, I have 3rd-instar larvae that I collected from their burrows at Blackjack Knob (adults mostly green) and Merriam Woods (adults mostly brown) and hope the rear them to adulthood next year.  If I succeed in getting virgin adults from the two sites, I think it would be interesting to do some single-pair crossings and rear the progeny to see how coloration is expressed.  A long term project, for sure, as these beetles probably require at least two seasons to reach adulthood, but rearing them is fun!  A more difficult, yet far more interesting, project would be to secure virgin adults from the mostly black main population in Texas – or even the bright green, thickly-maculated santaclarae subspecies from Arizona – to see how interbreeding them with these Missouri disjuncts would affect coloration and maculation in their progeny – they could be some of the most unusual appearing large grassland tiger beetles ever seen (not to mention their tongue-twisting taxonomic moniker of Cicindela (Cicindelidia) obsoleta vulturina [Missouri disjunct] x obsoleta santaclarae!).  Timing would be a difficulty, since the Texas and Arizona populations exhibit a more normal summer adult phenology, but it would be worth a try if I could secure a source of larvae for rearing.  Anybody?

A male sports his impressive pair of choppers.

Photo Details (insects): Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/13-22), Canon MT-24EX flash (1/4-1/2 ratio) w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Mawdsley, J. R.  2009. Geographic variation in U. S. populations of the tiger beetle Cicindela obsoleta Say (Coleoptera: Cicindelidae).  Insecta Mundi 0094:1–10.

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.

Copyright © Ted C. MacRae 2010

“Colorfull Cockroach” discovered in Panama

/ Ted C. MacRae / 11 Comments

I won’t call this a taxonomy fail, since Patrick is clearly not a taxonomist, or even the first person to confuse a beetle with a cockroach.  Nevertheless, I was amused at Patrick’s amazement with the “colorfull cockroach” that he found and his palpable excitement that it might be a new discovery.

Well, I was amazed about this type of cockroach so, I would like to know if it is a cockroach or what because I know you guys will be also interested about checking out this type of bug.
Thanks please answer fast 🙂
Maybe is a new kind of cockroach not discovered yet.

Fortunately, the folks at What’s That Bug were able to correctly identify this as Euchroma gigantea (giant metallic ceiba borer), a beetle in the family Buprestidae (and the largest such species in the Western Hemisphere).  An interesting note about this photo is that it shows the beetle with some – but not all – of the green pulverulence (dusty coating) that these beetles exhibit over the elytra upon emergence from their host tree.  This coating is quickly worn off as the beetle goes about its activities, and most museum specimens of the species lack it completely – giving the beetle a purplish appearance as seen on the left elytron of the beetle in this photo.  Even handling a freshly-emerged specimen to mount it on an insect pin would likely result in loss of much of the coating, so it is quite difficult to preserve specimens in their lime-green dusty state.

Copyright © Ted C. MacRae 2010

Sweet Sixteen!

/ Ted C. MacRae / 16 Comments

The 7th Annual Fall Tiger Beetle Trip™ is officially over – Chris and I rolled back into town a little after midnight last night. It was an amazing trip – perfect weather, unparalleled scenery, and a record-breaking 16 species of tiger beetles seen in 13 localities across four states. Not only does this beat my previous trip record of 13 species, but we did it with only five days in the field. At the time of my previous update, we had visited several locations in the South Dakota Badlands and Nebraska Pine Ridge and found ten different tiger beetle species, including Cicindela pulchra (beautiful tiger beetle) – our top priority for the trip – C. nebraskana (prairie long-lipped tiger beetle), and C. lengi (blowout tiger beetle). Our plan for the next day was to visit the Badlands of Wyoming to look for C. decemnotata (Badlands tiger beetle – appropriately) and the Yampa River Valley of northwestern Colorado to look for C. scutellaris yampae and C. formosa gibsoni, all three of which we managed to find (though with caveats – stay tuned). Our originally planned final field day was to take us back into Wyoming to look for C. longilabris (boreal long-lipped tiger beetle) in the mountains east of Laramie and the Nebraska Sand Hills to look for the delicate little C. limbata before heading back home. However, we were finally paid a visit by “the skunk” and did not see any of these species (although our sighting of C. limbata (common claybank tiger beetle) in Wyoming did officially break the old trip record). Not wanting to end the trip on a disappointing day, we delayed our departure for home yesterday and visited two more sites at the eastern edge of the Nebraska Sand Hills (sites M and N in the above map) – a clay bank site where we saw a robust population of C. denverensis (to augment the single individual we had seen earlier in the trip) and several C. splendida (splendid tiger beetle), and another sand dune/blowout system where we at last succeeded in finding C. limbata.

The day after the end of the Annual Fall Tiger Beetle Trip™ is usually a somewhat depressing day for me. Not only is the trip over, but likely so is the entire insect collecting season. I know I need the down time to process the specimens and knowledge acquired during the season, but the field work itself remains my favorite aspect of this pursuit. Nevertheless, the experiences from this trip will fuel my memories for years to come, and in the next weeks I’ll share some of the stories that unfolded. Until then, I leave you with this portrait of C. pulchra – looking rather annoyed with me for my persistent efforts to take his photograph.

Cicindela pulchra - the ''beautiful'' tiger beetle

Copyright © Ted C. MacRae 2010

2 days, 6 localities, 10 species…

/ Ted C. MacRae / 6 Comments

Here’s an updated itinerary for the 7th Annual Fall Tiger Beetle Trip that fellow cicindelophile Chris Brown and I are in the midst of. We’ve spent the past two days visiting six localities in Nebraska and South Dakota. So far, we’ve found a total of 10 species – including every species we had hoped to see at this point in the trip. The list so far (in chronological order) is:

  • Cicindela (s. str.) tranquebarica kirbyi – ho hum, we’ll see this in several places.
  • Cicindela (s. str.) purpurea audubonii – über common Great Plains species, although the black form is always a treat to see.
  • Cicindela (s. str.) pulchra – YEAH! Seen in good numbers at one of the new South Dakota localities discovered in 2008 by Matt Brust (our personal chaperone for the day). Marvelous field photographs.
  • Cicindela (s. str.) fulgida – Only one seen, but Chris got a nice series of field photographs (I’ve seen good numbers of this species from my previous trips to this area in 2008 and in Oklahoma last year).
  • Cicindela (s. str.) nebraskana – Another “A list” species for the trip, but we’ve only seen one so far.
  • Cicindela (Cicindelidia) punctulata punctulata – also known as Cicindela ubiquita.
  • Cicindela (s. str.) scutellaris scutellaris – even though this is a common Great Plains species in any sandy area, I never tire of its dazzling red elytra and blue/green head and pronotum.
  • Cicindela (s. str.) lengi – The third species on our “A list” that we’ve seen, with some real nice field photographs from Monroe Canyon.
  • Cicindela (s. str.) formosa generosa – another common Great Plains species.
  • Cicindela (s. str.) denverensis – I didn’t expect to see this one on the trip (just a single individual at Monroe Canyon), but I’ll take it!

Tomorrow we’ll hit a Wyoming location where Cicindela (s. str.) decemnotata is known to hang out – a species I’ve not yet seen, either alive or preserved. Most sources regard this species as closely related to C. denverensis, but Matt thinks it is actually more closely related to C. fulgida due to similarity in form and shine but green instead of purple. Afterwards, in a major addition to our planned itinerary (hence the updated Google Map), we’ll go into northwestern Colorado to look for two very cool subspecies of the otherwise widespread species – C. formosa gibsoni and C. scutellaris yampae. If we’re lucky we’ll also see the delicate little sand lover, Cicindela (s. str.) limbata, but if we don’t see it there then we should see it the next day when we finish out the trip back in the Nebraska Sand Hills just east of Alliance. But before that, we’ll veer back up into Wyoming and look around in the high elevations east of Laramie in hopes of finding Cicindela (s. str.) longilabris laurentii. That one may be a stretch, but if we are successful then we have the potential to see a total of 15 species – that would be a trip high for me (literally and figuratively).

Copyright © Ted C. MacRae 2010

The last survivor

/ Ted C. MacRae / 8 Comments

This past June I made two trips to the Loess Hills of extreme northwestern Missouri as part of a follow-up survey for Cylindera celeripes (swift tiger beetle).¹ I was hoping to identify additional populations, however small, of this tiny, flightless, enigmatic species to go along with the three that colleague Chris Brown and I discovered last year.  The results were good news, bad news – no new populations were found, but I was able to re-confirm the beetle’s occurrence at two of the sites where we found the beetle last year.

¹ Some of you may recall my excitement at finally finding this long-sought after species in Missouri – apparently limited to the state’s few remaining high quality loess hilltop prairie remnants.

One of the sites that I had hoped might harbor the beetle is Squaw Creek National Wildlife Refuge in Holt Co. – located very near McCormack Loess Mounds Natural Area where the beetle was seen both this year and last.  Squaw Creek features several thousand acres of restored wetland habitat in the Missouri River valley that serve as resting, feeding, and breeding grounds for migratory birds and other wildlife.  Located within the Mississippi Flyway, the refuge is best known for its large concentrations of snow geese and bald eagles.  Wetlands are not good habitat for C. celeripes, but it was not the wetlands I was interested in visiting (well, I am really interested in visiting the wetlands someday – but on these visits I had other goals).  Rather, it was the tiny slivers of loess hilltop prairie that still remain on the fingers of loess bluffs along the eastern boundary of the refuge.  Twice scouring these prairie remnants over a two-week period failed to reveal the presence of the beetle, but on the first visit I did see this lone, rather ragged-looking adult male Cicindela limbalis (common claybank tiger beetle).  Unlike the aforementioned species, C. limbalis is rather common throughout most parts of the state on upland clay exposures. A spring-fall species, adults first emerge in September, have a little fun (which includes feeding but not mating), and then dig back into the ground for the winter before emerging once again in the spring. It is one of the first insects to greet the new season (I’ve seen them as early as late March) – mating and oviposition occur over the next month or two, and by end of May these guys are pretty well spent.  An interesting feature of the populations found in extreme northern Missouri is their higher degree of elytral maculation.  Compare this relatively fully-marked individual with this female that I reared from a larva collected at Knob Noster State Park in west-central Missouri (incidentally, my first ever reared tiger beetle!).

This male is clearly among the last of his generation in this area – not only did I not see any other individuals on the entire trip, but he clearly exhibits signs of wear and tear.  I found him nibbling on this dead millipede (which larger tiger beetles are known to prey upon); however, I don’t think this guy actually killed the millipede.  Rather, I think he found it already dead and was scavenging one of the only meals still available to him.  Closer examination of the face reveals that his left mandible is broken off near the base (best seen in the enlarged photo) – whether a result of battle with over-sized prey or a narrow escape from predation himself is hard to say.  Regardless, with only one “tooth” his ability to capture prey on his own has been severely compromised, and about all he can do is look for already dead prey items on which he can scavenge.  As one of the last survivors of his class, one can only hope that he lived a long and fruitful life, killed much prey, and inseminated many females.

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/14-16), Canon MT-24EX flash (1/4 ratio) w/ Sto-Fen diffusers. Typical post-processing (levels, minor cropping, unsharp mask).

Copyright © Ted C. MacRae 2010

…the “better” Eleodes suturalis

/ Ted C. MacRae / 8 Comments

As I mentioned in my previous post, I really wasn’t satisfied with the photographs I took of the clown beetle, Eleodes suturalis, that I brought back from Oklahoma. I had placed the beetle in a terrarium of native soil and taken the obligatory whole beetle and head close-up photographs, both showing all the characters needed to identify the species in adequate detail. They were good, scientific photos, but they weren’t very exciting. In fact – they were boring! Now, I know not every subject I photograph is going to be a wower (the giant desert centipede I recently featured probably setting that standard), but it is important to me that the photographs I post here at least be interesting. After taking those first E. suturalis photographs, then being underwhelmed as I brought them up one-by-one on the computer, I started thinking about whether certain insects are just ‘homely’, and no matter how you photograph them they will still be homely. Eleodes suturalis is by no means a homely beetle in real life, but that is due mostly to the impressiveness of its size – a quality not easy to project in photographs.  Beyond that, its somber coloration, lack of unusual morphological modifications, and “beady little eyes” (fide Adrian) don’t offer much else in the way of help.  Combine that with the unflattering salmon coloration of its native soil as a substrate and an exoskeleton just shiny enough to cause annoying specular highlights, and you’ve got a recipe for really boring beetle photographs!

That’s when it occurred to me to try photographing the beetle in a white box.  I’ve only just begun to experiment with this technique and have been impressed with its ability to make somber-colored subjects (e.g., Gromphadorina portentosa) attractive and truly beautiful subjects (e.g. Buprestis rufipes) simply stunning.  The sharp, clean environment of a white box demands a clean beetle, so I gave the beetle (who had done much digging since the previous photo shoot) a good soaking and scrubbing (to the beetle’s great disapproval!).  Yes, I know there is still some dirt on him, but I think a dental pick and wire brush would have been needed to remove every last bit, caked on as it was!  Despite that, I think I achieved the desired effect – specular highlights… gone!  Boring background… gone!  Clean and crisp and ready to impress! The photos also do a much better job of highlighting the 3-dimensionality of the beetle than the original photographs.  Of the many photos I took, my favorite is featured above, and below I present two more that closely approximate the vantage of the two photos I posted from the first shoot in a side-by-side comparison.

For those of you wondering how I managed to secure the beetle’s cooperation for these photos, I used a modification of the “lens cap” technique, covering the beetle with a large glass bowl instead.  The beetle crawled around under the bowl for a bit but eventually would end up settled down against the edge.  By carefully lifting the bowl I was able to avoid disturbing the beetle and fire a few shots before it would start wandering again.  I just repeated the process until I was satisfied I had a few good shots in the sequence.

Does this mean an end to my preference for in situ photographs?  Certainly not.  But some beetles just look better in white!

Photo Details:
White box: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/18-20), Canon MT-24EX flash, indirect. Typical post-processing (levels, minor cropping, unsharp mask).
Terrarium: same except f/18, direct flash w/ Sto-Fen diffusers.

Copyright © Ted C. MacRae 2010