beetles

Return to Nowhere

/ Ted C. MacRae / 14 Comments

Back to some hard-core, field natural history.  Two years ago, on my virgin experience at collecting tiger beetles in Florida, I visited a spot called “Road to Nowhere”¹ at the suggestion of North American Tiger Beetle Master Dave Brzoska.  He said as many as 6–10 species can be seen there if the season is right, although my early August timing might be a tad late.  Despite having only a few hours from late afternoon to dusk to explore the area, I came close with the following five species: Cicindela trifasciata ascendens (Ascendent Tiger Beetle), Habroscelimorpha severa (Saltmarsh Tiger Beetle), Eunota togata togata (White-cloaked Tiger Beetle), Ellipsoptera marginata (Margined Tiger Beetle) and E. hamata lacerata (Gulf Beach Tiger Beetle) (see Tiger Beetles at Florida’s “Road to Nowhere”).

¹ For those of you who haven’t heard of the “Road to Nowhere,” it ranks as one of the top tiger beetle “hot spots” in the country (perhaps second only to Arizona’s famous Wilcox Playa).  According to Doug Taron at Gossamer Tapestry, the site—an expansive coastal salt marsh and mud flat along the isolated central Gulf Coast of Florida—was built some decades ago at the behest of corrupt state officials as a landing strip for small airplanes running drugs into this country.


One species I did not see on that trip is Habroscelimorpha striga (Elusive Tiger Beetle).  The common name is well deserved—the species is restricted to salt marshes, mud flats, and openings in coastal pine forest along the west and northeast coasts of Florida and South Carolina, and apparently nobody has ever seen it during the day (Pearson et al. 2006)!  Despite this, the Road to Nowhere is one place where the species can be seen somewhat reliably through its attraction to ultraviolet “blacklights.”  With this in mind, I began my 48-hour tiger beetle blitz during last August’s family vacation to Florida by timing my departure from St. Petersburg so that I arrived at the Road to Nowhere as dusk was falling—just in time to setup the lights, sit back with a beer, and wait for H. striga to cover the sheet!  The plan had a few kinks—I got a little bit of a late start, so by the time I got to Steinhatchee it was already getting dark.  Because of this, I missed one of the turns (my memory isn’t as good as it used to be) and got lost.  By the time I finally got my bearings, it was pitch black as I drove the 11-mile length of that lonely road through sand scrub and coastal marsh to a point where the road just simply stops.  Although the area is no longer used much for drug running, I still felt somewhat vulnerable as I setup the blacklight at the edge of the expansive salt mud flat.  There was one additional kink—I had forgotten to bring my copy of Pearson et al. (2006), any North American tiger beetle aficionado’s “Bible.”  Having only my memory of reading about the species to draw on, I hoped that I would recognize it if I saw it, or least recognize it as something different from the other species I expected to see there.


I’ve heard stories about the area being filled with tiger beetle collectors from all over the country with their blacklights and bucket traps, with someone yelling “striga!” every hour or so. However, I was the only person there that night. I hoped I wasn’t too late, as August is at the back end of the known adult activity period. Very quickly three other species, E. hamata lacerata, E. marginata and H. severa (the latter similar to H. striga, but much more abundant) began literally swarming all over the sheet and ground beneath. It was exciting at first, as I’d never encountered these (or any other tiger beetles) so abundantly at blacklights. In time, however, I satisfied my appetite for specimens and actually started becoming rather annoyed at their abundance—as if they might be “chasing away” the rare H. striga that was attracted to the light before I had a chance to see it.


Eventually, however, it happened. I spotted a somewhat different looking tiger beetle, but instead of yelling “striga!” my reaction was “What is that?” It was dark(ish), and I noted a subsutural row of green punctures on each elytron—”Is that punctulata?” I picked it up and looked at it closely, still thinking maybe punctulata but not sure. It was shinier, and a little bigger, and I noted the presence of marginal white spots at the middle and rear of the elytra. “No, that’s not punctulata… Is it striga? It must be striga! Yeah, it’s striga!” I dug down into the deep recesses of my memory and recalled that H. striga, indeed, was a darkish species, although I could not recall anything about the row of punctures. I finally decided that it really couldn’t be anything else but H. striga, an ID arrived at by process of elimination rather than recognition. Looking back, I feel a little cheated—I never got my “striga!” moment, that instant of sudden jubilation.  Instead, it was just a slow, creeping realization of what I had (listen to me—complaining about finding H. striga!).

I would actually find about a half dozen individuals of H. striga that night. The first one, per standard procedure, went live into a vial as a backup for studio photos if I didn’t manage to get any in the field.  That proved unnecessary, however, as I was able to photograph the two subsequent individuals shown in this post. It was not just H. striga that kept me busy with the camera, but feeding, perching, and trophy-bearing individuals of E. hamata lacerata and some other species that I have still to discuss as well. It was non-stop action from the time I setup the lights, interrupted only briefly at one point as I nervously watched a set of car headlights approach from the distance, stop a few hundred yards up the road, and then slowly turn around and disappear. By the time I finally took a moment to look at my watch it was already 1 a.m.! Soaking wet from the nighttime humidity, dirty from laying on the salty, muddy ground, and exhausted from the 4 hour drive and non-stop action after my arrival, I finally packed up the lights and began the drive back to civilization—praying that I would be able to find a motel without too much delay!

REFERENCE:

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 2011

Another account of the recently rediscovered Cicindelidia floridana

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Back in August I had the chance to see with my own eyes wild individuals of Cicindelidia floridana, a tiger beetle that had been recently rediscovered after being thought extinct for nearly a century.  Accompanying me during that trip were Chris Wirth (author of the tiger beetle blog Cicindela) and Dave Brzoska (tiger beetle collector extraordinaire, and lead author of the paper announcing the beetle’s rediscovery).  I recounted that experience in my post Photographing the Newly Rediscovered Cicindelidia floridana, and now Chris has done the same in his post Revisiting the recently rediscovered C. floridana.  Chris has perhaps the most perfect field photograph of one of these beetles—go check it out (and while you’re there read about his first trip to see the beetle in his post Presumed extinct, Floridian tiger beetle rediscovered after 73 years).  And so that you don’t leave here empty-handed, here is another photograph of the beetle that didn’t quite make the cut in my earlier post:

Cicindelidia floridana | Miami-Dade Co., Florida

Copyright © Ted C. MacRae 2011

Bee Fly Parasitism of Tetracha virginica

/ Ted C. MacRae / 25 Comments

I expected to gain a better understanding of insect photography principles and techniques at last weekend’s BugShot insect photography workshop at Shaw Nature Reserve in Gray Summit, Missouri.  I even expected that I would walk away from the event with some new friends.  The one thing I did not expect was the discovery of an apparently unreported host/parasitoid relationship amongst my beloved tiger beetles.  Nevertheless, that’s exactly what happened in a patch of barren soil just outside of the Dana Brown Education Center where the event was being held.

Tetracha virginica 3rd instar larva | Shaw Nature Reserve, Franklin Co., Missouri

I had spied the small cluster of tiger beetle burrows the previous day as we left on our first group hike.  The burrows were unmistakably those of Tetracha virginica (Virginia metallic tiger beetle) due to their size (no other tiger beetle in east-central Missouri approaches the size of this species), and in fact some of the larvae were seen sitting at the tops of their burrows.  Tetracha larvae are easily distinguished from other genera of North American tiger beetles (in addition to their size) by their distinctive white-margined pronotum.  I had to catch back up with the group but came back later in the day and took a few photographs of one of the larvae sitting in its burrow.  Some of the other BugShot attendees were there and wanted to take photographs, but the larvae dropped on their less-practiced approach.  No problem, I just “fished” a larva out of its burrow and let them take their photographs.  When they finished, I began taking my own photographs, but I only got off one shot before the larva suddenly made a bee-line for its burrow and dropped in before I could block its escape.  Oh well, I do already have photographs of the larva of this species from other locations.

Tetracha virginica 3rd instar larva | Shaw Nature Reserve, Franklin Co., Missouri

The next day I passed by the burrows again with Crystal and Lee.  I really wanted them to see the larvae, but they were not active.  No problem, I grabbed a long grass stem, chewed on one end, and inserted it to a depth of about 35 cm before it hit bottom.  A little jiggling to get the larva to bite, then a quick jerk back and out came the larva.  I never tire of seeing someone witness this for the first time—the way they jump back half-startled when they see the otherworldly larva flying through the air and landing on the grass.  I grabbed the larva and placed it on the barren clay to let them take photographs.  Crystal went first, and as she looked at the larva through her viewfinder she exclaimed, “there are wormy-things [the technical term, of course] on him.”  Lee and I looked, and sure enough there were two small “wormy-things” attached to the back of the tiger beetle.  I immediately recognized them as bee fly larvae (family Bombyliidae)—specifically Anthrax analis, the only bee fly known to parasitize tiger beetle larvae in the United States.  I was quite excited by this discovery, as I have never seen these before despite fishing untold numbers of tiger beetle larvae from their burrows over the past decade or so.  We all went camera crazy and took our turns photographing larvae and host, after which I popped it into a vial to keep for an attempt at rearing out the bee flies.

Anthrax analis larvae attached to abdomen of Tetracha virginica larva

It now seems that our find represents more than just a personal discovery, as bee flies—to my knowledge—have not yet been reported parasitizing any species of the genus Tetracha.  Of the 70 Anthrax spp. for which hosts have been recorded (Yeates and Greathead 1997), only three are known to parasitize tiger beetles.  Shelford (1913) gave the first account of A. analis (as Spogostylum anale) parasitzing Cicindela scutellaris lecontei, noting that the adult females lay their eggs by flying backward and downward while thrusting the abdomen forward until it touches the sand near the host burrow entrance.  Hamilton (1925) found Cicindelidia obsoleta parasitized by this species, and Bram and Knisley (1982) expanded its known host spectrum to include C. hirticollis, C. tranquebarica, Cicindelidia punctulata, and Ellipsoptera marginata.  Photographs of larvae (presumably of this species) parasitizing undetermined tiger beetle larvae can be seen in Pearson and Vogler (2001) and in this photo by Chris Wirth.  Anthrax gideon has been recorded parasitizing Pseudoxycheila tarsalis in Costa Rica (Palmer 1982) and Oxycheila trisis in Brazil (Arndt and Costa 2001), while a third undetermined Anthrax sp. has been reared from larvae of Pentacomia ventralis, also in Brazil (Arndt and Costa 2001).  Oxycheila and Pseudoxycheila are related to Tetracha at the tribal/subtribal level (depending on which classification you follow), so the finding of A. analis utilizing Tetracha is not unexpected.

Closer view of anteriormost Anthrax analis larva

The beetle larva and its unwelcome tagalongs is now in a container of native soil and has accepted the starter burrow that I made for it. Hopefully at least one of the bee fly larvae will complete its development and emerge as an adult to allow confirmation of its identity.  If this host association does turn out to be unreported, we will follow up with at least a short journal communication.  To that end, any literature citations you are aware of regarding bee fly parasitism of tiger beetles that is not listed below would be most welcome.

Congratulations to Ben Coulter, who wins yet another BitB Challenge with 14 points (this guy is a machine!), and Mr. Phidippus came close with 13 points.  Ben and Phiddy were the only participants that figured out the parasites were bee flies of the genus Anthrax, and Phiddy was the only participant to guess the correct genus for the host.  Ben’s win gives him a now commanding lead with 49 points in the current BitB Challenge Session #4 as we enter the home stretch.  Mr. Phidippus and Roy are still in striking distance with 39 and 28 points, respectively.  Is anybody capable of keeping him from his third title?  We shall see.

REFERENCES:

Arndt, E. and C. Costa.  2001.  Parasitism of Neotropical tiger beetles (Coleoptera: Carabidae: Cicindelinae) by Anthrax (Diptera: Bombyliidae).  Studies on Neotropical Fauna and Environment 36(1):63–66.

Bram, A. L. and C. B. Knisley.  1982.  Studies on the bee fly Anthrax analis (Bombyliidae), parasitic on tiger beetle larvae (Cicindelidae).  Virginia Journal of Science 33:90.

Hamilton, C. C. 1925. Studies on the morphology, taxonomy, and ecology of the larvae of Holarctic tiger beetles (family Cicindelidae).  Proceedings of the U.S. National Museum 65 (Art. 17):1–87.

Palmer, M. K.  1982.  Biology and behavior of two species of Anthrax (Diptera: Bombyliidae), parasitoids of the larvae of tiger beetles (Coleoptera: Cicindelidae).  Annals of the Entomological Society of America 75(1):61–70.

Pearson, D. L. and A. P. Vogler.  2001. Tiger Beetles: The Evolution, Ecology, and Diversity of the Cicindelids.  Cornell University Press, Ithaca, New York, 333 pp.

Shelford, V. E.  1913.  The life history of a bee-fly (Spogostylum anale Say) parasite of the larva of a tiger beetle (Cicindela scutellaris Say var. lecontei Hald.).  Annals of the Entomological Society of America 6(2):213–225.

Yeates, D. K. and D. J. Greathead.  1997. The evolutionary pattern of host use in the Bombyliidae (Diptera): a diverse family of parasitoid flies.  Biological Journal of the  Linnaean Society 60:149—185.

Copyright © Ted C. MacRae 2011

Bumelia borer on white

/ Ted C. MacRae / 19 Comments
Plinthocoelium suaveolens suaveolens | Ozark Co., Missouri

Last weekend I visited one of my favorite collecting spots in all of Missouri—Long Bald Glade Natural Area (part of Caney Mountain Conservation Area in Ozark Co.).  Nestled at the eastern edge of the White River Hills in southwestern Missouri, its deeply dissected hills are home to numerous plants and animals that are more typical of the southern Great Plains and which have found refuge in the xeric, thin-soiled calcareous prairies (commonly “cedar glades”) that cover the area’s southern- and western-facing slopes.  These include some rather impressive insects, such as a disjunct population of Cicindelidia obsoleta vulturina, which I just found here last year as the new northeasternmost extent of the population, as well as the marvelously monstrous Microstylum morosum, North America’s largest robber fly and so far known in Missouri only from Long Bald Glade where it was discovered in 2009. 

Another quite striking insect found at Long Bald Glades (though not restricted in Missouri to the White River Hills) is the bumelia borer, Plinthocoelium suaveolens.  This beetle occupied much of my time in July 2009 as I committed to photographing the species in the wild, and it was Long Bald Glade where I finally (if not completely satisfactorily) succeeded in that goal.  This time I was visiting the Glade to look for the earliest individuals of C. obsoleta vulturina and, hopefully, document additional glades within Caney Mountain that might support the beetle.  However, in the back of my mind I was also keeping a lookout for P. suaveolens—this species is primarily active during July and August in Missouri, but I do have records of it as late as September.  As I looked for (and found) tiger beetles, I also checked out each bumelia tree that I passed hoping to see a P. suaveolens adult perched on its lower trunk.  It was not until later in the afternoon that I heard a loud “buzz” approaching from behind and turned to see one of these beauties fly right past me—legs and antennae held outstretched—before landing on a nearby tree.  Now, over the years I’ve learned a few lessons, and one is that you don’t try to take in situ photographs of the first individual you encounter of a prized species.  More often than not it gets away before you even fire the first shot, and you’re left with nothing.  My standard procedure now is to procure the first individual immediately and keep it alive.  If attempts to photograph subsequent individuals are not successful (or none are seen), then at least I have a backup for studio shots (not my first choice, but better than nothing!).  Such was the case with this individual.

Although I still lack that “perfect” beetle-on-a-branch shot that I hope to eventually get for this species, it seemed a good subject for some white-box photography.  I’ve vacilated between true white-box w/ indirect flash versus getting a white-box effect by using direct, diffused flash with the subject on a white background.  I decided now was the time for a direct comparison of the two techniques.  All of the following photographs were taken with the Canon 100mm macro lens on a Canon 50D body at 160 ISO, 1/200 sec, and f/16.  For the closeups (photos 3 and 5 of each series), 68mm of extension tubes were added.  The photos on the left are true white-box photos, i.e. the flash heads were directed up and away from the subject placed inside a box lined with white tissue (Kim-Wipes laboratory wipers).  The photos on the right mimic the white-box effect by placing the subject on white filter paper, but the flash heads were pointed directly at the subject through my DIY concave diffuser (click on photos for 1200×800 versions):

Indirect flash in white box

Direct flash w/ DIY diffuser

Indirect flash in white box

Direct flash w/ DIY diffuser

Indirect flash in white box

Direct flash w/ DIY diffuser

Indirect flash in white box

Direct flash w/ DIY diffuser

Indirect flash in white box

Direct flash w/ DIY diffuser

I must admit, looking at the photos on the camera playback screen I had the impression that I would like the direct-diffuser photos better, but after reviewing them on the computer and applying typical post-processing enhancements (e.g., levels, slight shadow reduction, and unsharp mask), the true white-box photos appear to have benefited from more even lighting, resulting in truer color, less shadowing, and minimal specular highlighting.  Not that the direct-diffuser photos are bad—they’re just not as good as the white-box photos.  I guess what this means is that my DIY diffuser, while a significant improvement over my previous diffusers, still could use some improvement (if ability to create white-box-like results is the ultimate test of a diffuser’s effectiveness).  I’d be interested in knowing your opinions based on these comparisons.

Congratulations to Ben Coulter, who wins yet another Super Crop Challenge and strengthens his lead in the overall standings of the current BitB Challenge Session #4 with 13 points.  Mr. Phidippus also correctly identified the species and takes 2nd place in the challenge with 8 points, keeping him in 2nd place in the overall standings as well.  Morgan Jackson takes 3rd place in the challenge with 7 points, but Roy’s retains 3rd place in the overall standings by way of his 6 points in this challenge.  Congratulations to these top points earners, and thanks to all who played.

Copyright © Ted C. MacRae 2011

Use of extension tubes for better lighting

/ Ted C. MacRae / 17 Comments

The photos in this post of Tetracha floridana (Florida Metallic Tiger Beetle) illustrate a technique that I have begun using recently to improve the lighting in my full-flash insect macrophotographs—use of extension tubes!  I know this sounds strange, and I actually just stumbled onto it myself when I started using extension tubes in combination with my Canon EF 100mm macro lens.  Okay, I can hear it now: “Why not use the Canon MP-E 65 mm macro lens?”  It’s a good question, as at magnifications above 1X there is no finer lens than the 65mm.  However, the tiger beetles that I spend a lot of time photographing are right in that size range where sometimes I need magnifications below 1x (whole body shots of medium to large species), while other times I need magnifications above 1X (small species and closeups—particularly face shots).  Fortunately, the entire spectrum of magnifications (up to 5X) is covered by these two lenses, but there is, unfortunately, no overlap.  This is where the extension tubes come in—when all 68mm are added the 100mm lens effectively changes from a 1.0X–∞ lens to a 0.7–2.0X lens.  This gives a frame width of 11–33 mm, perfect for nearly all North American tiger beetles (most species range from 6-20 mm, excluding legs and antennae). 

In addition to allowing a more appropriate range of magnifications without the need to switch out lenses, this has one other effect—it moves the lens a little closer to the subject.  That in itself is of no particular benefit, but since I use the front-of-the-lens-mounted Canon MT-24EX dual flash, it also moves the flash a little closer to the subject.  It’s not a huge distance, only about 20 mm, but keep in mind that the flash heads extend forward from the front of the lens (especially with the Kaiser shoes that I use with my diffuser), and the front of the diffuser itself lies at about 60 mm in front of the lens face.  Thus, at 1X the the front of the diffuser sits ~80 mm from the subject with the 100mm lens only, but with 68 mm of extension tubes added it sits only 60 mm from the subject.  The closer the light source is to the subject, the greater the apparent light size, and larger apparent light size results in more even lighting with reduced specular effects.

Tetracha floridana | Pinellas Co., Florida (100mm lens only)

100mm lens + 68mm extension tubes

100mm lens only (slightly cropped)

100mm lens + 68mm extension tubes

The primary disadvantage to doing this is loss of ability to focus to infinity.  Frankly, this is functionality I never used with the 100mm lens, preferring instead the 17-85mm wide-angle lens for more general landscape and habitat photos.  The other downside is that placing the lens closer to the subject can result in greater chance of “spooking” the subject and causing it to flee or behave evasively.  Again, however, my experience is that if a subject can be photographed at 1X with the 100mm lens, it can be photographed at 2X with the 100mm lens + extension tubes.

Has anybody else ever tried this, and if so what was your experience?

Copyright © Ted C. MacRae 2011

Charming Couple revisited

/ Ted C. MacRae / 4 Comments

Another view of the of Ellipsoptera hamata lacerata (Gulf Coast Tiger Beetle) that I photographed in a small mangrove marsh in Seminole, Florida. These are actually among the first tiger beetles that I ever tried to photograph at night, and the major learnings involved: 1) figuring out how to turn on the flash lamp and then compose the shot quickly enough before the lamp shut off, and 2) making sure to use the histogram in the field to ensure I’d gotten the proper flash level. My first few attempts all tended to be underexposed because the brightness of the image on the playback screen in the darkness caused me to keep undersetting the flash exposure compensation. I’d not previously gotten in the habit of using the histogram in the field since I do a lot of flash level bracketing, but perhaps this is a tool that will allow me to cut down on that to some degree. Anyway, these are two additional photos that worked out pretty well—I like the first because of the contrast between the bright white mandibles of the male versus the off-white mandibles of the female, and the second (female only after the male bolted) for its nice view of the curiously bent elytral apices that distinguish it from the female of the very similar and (in this area) sympatric E. marginata (Margined Tiger Beetle). Also clearly seen in the second is one of the distinct basolateral grooves on the pronotum that serve to receive the male mandibles during mating (compare to same area on pronotum of male). I was amazed at how easy this mating pair and other individuals of this species were to photograph at night in view of their extreme wariness during the day.

Ellipsoptera hamata lacerata | Seminole, Pinellas Co., Florida

Note curiously bent elytral apices and basolateral pronotal groove for reception of male mandibles.

Copyright © Ted C. MacRae 2011

Gnom, Gnom, Gnom…

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I’ve become a big fan of night-time tiger beetle photography since my early August trip to Florida.  Not only does it open up the world of nocturnal species that might go undetected during the day, it also affords the opportunity to see diurnal species engaged in behaviors that are more difficult to photograph during the day.  This female Gulf Beach Tiger Beetle (Ellipsoptera hamata lacerata) came to my blacklight at a coastal salt marsh near Steinhatchee and promptly began munching on a smaller beetle that had also come to the light.  I didn’t get a good enough look at the prey early on to identify it, and by the time I was able to zoom in big with the camera lens the prey had already been macerated to a crunchy pulp.  It was interesting to watch the tiger beetle grasp and chew the prey with its mandibles while manipulating its position with its maxillary parts.




Copyright © Ted C. MacRae 2011

Why I Roamed the Marsh at Night

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Tetracha floridana (Florida Metallic Tiger Beetle) | Pinellas Co., Florida

For two years I waited.  The narrow strip of coastal scrub and mangrove marsh along the intracoastal waterway behind my sister-in-law’s condominium in Seminole, Florida had been an unexpected surprise during my first visit in August 2009.  Despite its small size and urban surroundings, it proved to be a good spot for tiger beetles, including Ellipsoptera marginata (Margined Tiger Beetle) and the closely related E. hamata lacerata (Gulf Coast Tiger Beetle).  Also living there was a much rarer tiger beetle—the Florida-endemic species Tetracha floridana (Florida Metallic Tiger Beetle), but I did not know this at the time.  In fact, had I not happened upon some larval burrows as I was leaving the preserve and decided to collect a few and rear them to adults, I would still not know they were there.  Only after the two larvae that made it back to St. Louis alive emerged as adults in their rearing container did I realize what I had found.  The reason I had not seen any adults during my visit was simple—they, like all members of the genus to which they belong, are strictly nocturnal!  Nevertheless, I knew I would return sooner or later and have another shot at seeing adults of this species in the wild.

A male, distinguishable by the thick brushy pads on the front tarsi.

And return I did.  My wife and I decided fairly early this year that we wanted to return to Florida for our summer vacation.  She likes the beach and her sister, and the kids like the beach and their aunt.  I don’t like the beach so much (though my sister-in-law is pretty cool), but I love Florida for its diversity of tiger beetle species and their high level of endemism.  During my 2009 trip I managed to find nine species, which, in addition to T. floridana, included also the very rare and potentially threatened Cicindelidia highlandensis (Highlands Tiger Beetle), known only from the Lake Wales Ridge in central Florida, and the (near) endemic Ellipsoptera hirtilabris (Moustached Tiger Beetle).  This year I set my sight on several other endemics—e.g. Cicindelidia floridana (Miami Tiger Beetle)—and near-endemics—e.g. Cicindelidia scabrosa (Scabrous Tiger Beetle).  My searches for these targets would have to wait for a few days, but for T. floridana I had only to wait until nightfall on the day we arrived.  The bleating chorus of tree frogs was my signal, and as the rest of the family retired to their bedrooms I geared up with my collecting fanny pack, camera bag and headlamp and headed out to the marsh.

The species lacks the violaceous reflections found on the elytra of T. carolina.

As I mentioned in my previous post, it was a little unnerving to walk into the marsh surrounded by darkness and greeted by scuttling hordes of sea slaters.  The anticipation of finally seeing T. floridana, however, was more than enough motivation to forge onward while deliberately scanning the ground with my headlamp.  For some amount of time I focused on the more barren areas, which is where I would have expected the adults to occur, but only after I also began scanning some of the sparsely vegetated ground—typically slightly elevated above the moister and more barren areas—did I see the first adult.  Its agile dash into and through the vegetation upon my approach was a little surprising and required more effort than I expected to finally capture it.  Elation!  Finding rare species is always a treat, but it is extra special when you find one where nobody previously knew it existed.  Over the course of the next 1½ hours (as well as the following night and two nights after that) I would see countless adults, giving me comfort that I could collect a reasonable voucher series without causing negative impacts on the population.

A female oviposits in the soil amongst the sparse, salt-tolerant vegetation.

I had hoped to see mating pairs but never did; however, I did find a female in the act of oviposition.  Consistent with the apparent adult preference for sparsely vegetated areas rather than barren ground, the female was nestled amongst the vegetation while she excavated a hole for the egg she would lay.  On the last night that I visited the marsh, I focused my efforts on finding larval burrows, starting in the area where I had seen them two years ago.  I only found a few but succeeded in fishing one 3rd-instar larva out of its burrow.  You see, even though I photographed one two years ago, the larva of this species remains undescribed in the literature.  Since I allowed the two larvae I had collected to complete their development to adulthood, I still lacked preserved specimens that could be used for the basis of a description.  I now had one, but for a formal description it would be better to have at least a few examples.  Remembering that I had seen the female ovipositing amongst vegetation rather than out in the open, I began searching the nearby vegetated areas for burrows.  This approach was met with better success, and from the dozen or so burrows that I was able to find, I succeeded in fishing out two more 3rd-instars.  I already have several preserved larvae of Tetracha virginica (Virginia Metallic Tiger Beetle) and a single T. carolina (Carolina Metallic Tiger Beetle) collected in southeastern Missouri by my good friend Kent Fothergill—this small series of T. floridana now leaves me lacking only the also-undescribed T. impressa (Upland Metallic Tiger Beetle) among the four North American (sensu stricto) species of Tetracha.  I will be anxious to compare the larvae of T. floridana I now have with those of T. carolina and T. virginica in an effort to find species-specific characters.

This male is sporting some very impressive teeth on his mandibles.

Copyright © Ted C. MacRae 2011