Cicindela scutellaris rugata (the “wrinkled tiger beetle”)

During last year’s Fall Tiger Beetle Collecting Trip, I visited several rural cemeteries in northeastern Texas. No, this was not a diversion from my beetle collecting—cemeteries in rural areas can be great places to look for tiger beetles because they tend to be lightly managed parcels of land of low agricultural value, thus retaining to some degree the character of the original landscape. In this case, the cemeteries I visited were located in the northern part of Texas’ Post Oak Savannah, a transitional ecoregion with uplands characterized by deep sandy soils supporting native bunchgrasses and scattered post oaks. It is the open, sandy areas in this region where distinctive subspecific populations of two more broadly distributed tiger beetles can be found—Cicindela scutellaris rugata and Cicindela formosa pigmentosignata. One location where I looked for them was an old cemetery in Henderson County. Within minutes of stepping out of the car, I found the first subspecies—unmistakable by its solid shiny blue coloration.

Cicindela scutellaris rugata

Cicindela scutellaris rugata Vaurie, 1950—Henderson Co., Texas

Cicindela scutellaris rugata, dubbed the “wrinkled tiger beetle” by Erwin & Pearson (2008), is one of seven recognized subspecies of this widely distributed species that shows greater geographical variation than any other species of tiger beetle in North America (Pearson et al. 2006). Across its range the species is found in deep, dry sand habitats that are fully exposed to the sun and lack any standing water. Except in the far southeastern U.S., this species is often found in association with C. formosa (although in Missouri I have noted that C. scutellaris occurs slightly earlier in the spring and slightly later in the fall—perhaps at least in part to avoid direct competition with and possibly even predation by that larger species).

Cicindela scutellaris rugata

The “wrinkled tiger beetle” exhibits solid blue to blue-green coloration with no maculations.

This subspecies is similar in appearance to C. s. unicolor, distributed across the southeastern U.S. and separated from C. s. rugata by the Mississippi River floodplain—both are shiny blue to blue-green in coloration and exhibit no maculations on the elytra. However, C. s. rugata has a more wrinkled pronotum (hence, the subspecific epithet) and smoother head, while C. s. unicolor has a smoother pronotum and more wrinkled head. Another subspecies, C. s. flavoviridis, shares this surface sculpturing but differs in having the elytra colored lighter yellow-green—in this sense C. s. rugata can be considered intermediate between C. s. unicolor to the east and C. s. flavoviridis to the west (Vaurie 1950). Cicindela s. rugata can also be confused with immaculate forms of C. sexguttata (six-spotted tiger beetle), but the latter is less robust with a more tapered posterior, and both sexes of C. sexguttata have a whitish labrum (in all subspecies of C. scutellaris only males have a white labrum, while females have a dark to black labrum).

Cicindela scutellaris rugata

The more wrinkled pronotum and smoother head distinguishes C. s. rugata from C. s. unicolor.

As I have noted for other C. scutellaris subspecies that I have encountered (nominate as well as C. s. leconteiC. s. yampae, and Missouri’s intergrade population of C. s. unicolorC. s. lecontei), adults were fairly abundant during the late morning hours but largely disappeared during the afternoon, probably having dug into their burrows to escape the midday heat (although I did not search for the burrows and dig them out as I have done for the other mentioned subspecies). I did see a very few individuals at another sandy cemetery in neighboring Van Zandt Co. that I visited later in the afternoon (and at both locations I found the stunning C. formosa pigmentosignata—that will be the subject of another post).

REFERENCES:

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

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

Vaurie, P. 1950. Four new subspecies of the genus Cicindela (Coleoptera, Cicindelidae). American Museum Novitates 1458:1–6 [AMNH Digital Library pdf].

© Ted C. MacRae 2016

Guest Post: Burrow Hole Blues

For today’s post, I am pleased to introduce nature writer and guest blogger Sharman Apt Russell. Epitomizing the increasingly important role of citizen scientists in conservation and natural history study, Sharman recently engaged in a year-long study of the Western red-bellied tiger beetle. Her experiences studying this little-known insect form the basis of her latest book, Diary of a Citizen Scientist. Chasing Tiger Beetles and Other New Ways of Engaging the World. With writing that is both humorous and whimsical, Sharman highlights the extraordinary scientific contributions being made by ordinary people. Of course, tiger beetles and citizen science are two subjects right up my own alley, so I’m avidly reading my own copy right now. I hope you’ll pick up a copy too (see ordering information below). The following excerpt from the book was kindly provided by the author.

When you’re a hammer, everything looks like a nail, and when you’re looking for the larval burrow hole of a Western red-bellied tiger beetle or Cicindela sedecimpunctata,  you see a surprising number of holes you’ve never seen before. Usually they are not the right size or shape, but you think about them anyway because suddenly you are curious: who lives inside all these holes?

Western Red-bellied Tiger Beetle adult. Photo by Cary Kerst.

Western red-bellied tiger beetle adult. Photo by Cary Kerst.

In Arizona and New Mexico, the Western red-bellied tiger beetle is a common and abundant species that comes out in June, before the summer rains, to congregate around ponds and ditches and river banks. For the last few years, as a citizen scientist, I have been trying to fill in what we don’t know about this insect, which includes what kind of habitat the females lay their eggs. Once these tiger beetle eggs hatch, the tiny larvae start digging vertical burrows, the entrance almost perfect circles in the dirt that increase in size (1-3 millimeters) as the larva goes through three stages or instars and enlarges the burrow. But where are those blankety-blank burrows? Does this beetle oviposit close to water or as much as a half mile away, like Cicindela marutha, the aridland tiger beetle? What kind of soil do Western red-bellies prefer?

Western Red-bellied Tiger Beetle larva. Photo used with permission.

Western red-bellied tiger beetle larva. Photo used with permission.

My entomologist-mentors David Pearson and Barry Knisley, coauthors of A Field Guide to the Tiger Beetles of  the United States and Canada, want to know the answers to these questions, and I’ve promised them that I would find out. So far, for three years, I’ve broken that promise, looking up and down the Gila River in southwestern New Mexico without success. About this time, in late fall, I start to give up, thinking that the larvae have closed their tunnels in order to overwinter.

On one last walk along the Gila River, a few holes remain to tempt me.

A number of almost-perfect circles in the dirt, eighty feet from the riverbank where I have seen hundreds of adult Western red-bellied tiger beetles congregate in the summer, are too large but still irresistible. Hole after hole, nothing lives there now. Instead something probably emerged months ago.

Tiny perfect circles in the dry upland grass are promising. Tiny ants are passing by, and I can see how the fiercely predacious tiger beetle larvae might lunge from such a hole to catch one of these ants. Then I notice how often the ants are marching into these holes, which are obviously their nests.

Other holes near the trail I am walking have turrets or small mud chimneys. I don’t bother to look inside these, knowing they were not built by the Western red-bellied tiger beetle—whom I have reared up in terrariums. (Yes, I have seen their larval burrow holes, just not in the wild.) Possibly these are the old nests of digger bees whose turrets prevent parasitic flies from flipping their eggs into the burrow to hatch and devour the bee larvae. Similarly, Williston tiger beetles construct turrets like this on salt lake beds in eastern New Mexico.

Closer to the Gila River, in dry cliffs that once marked the river’s channel, I see lots of cicada emergence holes and what I think is the home of a tarantula. Tarantulas start their burrows as spiderlings and live there a lifetime, as long as ten years if male and twenty-five if female. This entrance is over an inch in diameter and covered with a light veil of silk that keeps in humidity and carries vibrations down into the foot-long tunnel with its J-shaped chamber. About three inches long, fully-grown tarantulas hunt beetles and grasshoppers and other small prey at night. Their defense against the foxes and coyotes and raccoons who like to eat them are irritating abdominal hairs that fall off easily and get into a predator’s eyes or nasal passages. (Coatis have learned to dislodge those hairs by vigorously rolling the spider back and forth along the ground.) Most people who walk around the Southwest become fond of tarantulas and think of them as lucky, much like having a roadrunner cross your path. I always give a glad mental shout—hey, neat! a tarantula!

Along the river now are signs of beaver chewing on tree trunks; perhaps a den is nearby. Southwestern beavers tend to make bank dens rather than lodges, a bank den having several entry tunnels with one above the high water mark. Its single inside chamber is about two by three by three feet. Other holes I’ll see on this walk might be made by gophers or ground squirrels, pocket mice or grasshopper mice. Collared lizards and whiptails use the holes made by other animals but occasionally dig their own burrows with a half-inch, half-moon shaped entrance. Wintering snakes also borrow someone else’s hole and sometimes den communally, rattlesnakes and bull snakes and whipsnakes all together. Burrowing owls modify the holes they find by lining the interior with feathers, food debris, and horse and cow dung. A Field Guide to Desert Holes says blandly, “This may be to disguise their scent to predators or as decoration.” Similarly, skunks borrow burrows or make their own, decorating them with a strong musky odor. Coyotes only use dens when birthing and raising pups, often on a hillside or bank, the hole taller than wide. There are a few large mysterious holes near my house that I like to think were made by a badger, a prodigious and powerful digger.

I guess we just see the top half of life. Somewhere, I know, the larvae of the Western red-bellied tiger beetle are bedding down now at the bottom of their tunnels (at least 15 centimeters deep), quiescent, waiting for winter to pass. In the spring, they’ll emerge again to catch prey. Eventually they will pupate into adults, congregating in June along the Gila River. Their life cycle is still a bit of a mystery. Maybe I’ll solve that mystery next year—or the next or the next.  In the meantime, I could be doing worse things with my life than looking for holes.

Western Red-bellied Tiger Beetles mating. Photo by Mike Lewinski.

Western red-bellied tiger beetles mating. Photo by Mike Lewinski.

About the author
Sharman Apt Russell lives in the Gila Valley of southwestern New Mexico and teaches at Western New Mexico University and Antioch University in Los Angeles. Her books related to entomology include Diary of a Citizen Scientist: Chasing Tiger Beetles and Other New Ways of Engaging the World (Oregon State University Press, 2014) and An Obsession with Butterflies: Our Long Love Affair with a Singular Insect (Basic Books, 2005). Her work has been widely anthologized and translated into over ten languages. For more information, please go to her website and consider signing up for her infrequent newsletters www.sharmanaptrussell.com.

Ordering Information
Title: Diary of a Citizen Scientist
Author: Sharman Apt Russell
Publication Date: October 2014
Price: $18.95 paperback
Description: 224 pp., 6×9 inches
ISBN: 978-0-87071-752-9
Ordering: Available in bookstores or by calling 1-800-426-3797. Order online at http://oregonstate.edu/dept/press

© Sharman Apt Russell 2014

Tiger beetles in Argentina’s Chaco forest

The day after I photographed Brasiella argentata on the mud/san banks of the Rio Paraná in Corrientes, Argentina, I decided to drive westward into the heart of Chaco Province. The destination: Chaco National Park, where some of the best remaining examples of the original “Gran Chaco” remain. Once covering nearly a million square kilometers in northern Argentina, Paraguay and Bolivia, this distinctive ecoregion has been largely converted to a vast, hot sea of cotton fields and mesquite fence-rows. A unique plant community in the Gran Chaco is the quebracho forest that takes its name from quebracho colorado chaqueño (Schinopsis balansae)—a tall, massively-trunked tree (related to, of all things, poison ivy!) with beautiful red wood that has been logged relentlessly wherever it occurs. Chaco National Forest is unique for the largely intact example of this forest it preserves and the mature quebracho trees that it contains.

Odontocheila chrysis | Chaco National Park, Argentina

Odontocheila chrysis (Fabricius, 1801) | Chaco National Park, Argentina

Insect life was not abundant as I walked the dark forest path. The lateness of the season (early April) and long-enduring drought occurring in the region had taken their toll, and I was content to see just about anything. At one point, a flash of movement caught my eye, and as I scanned the forest floor in the area where I had seen it, the familiar silhouette of a Golden Forest Tiger Beetle—Odontocheila chrysis (Fabricius, 1801)—became visible. I was already familiar with this species, having seen fairly good numbers of them at another location further east during my first visit to the area 12 years earlier. Long-legged and fast-flying, this tiger beetle occurs throughout much of South America, where it lives in more shaded areas of forest clear-cuts, secondary forests, savannas, and open scrublands (Erwin & Pearson 2008). The ground-dwelling adults are known to congregate along paths and at large openings on the forest floor, and indeed I had seen them in their greatest numbers on a shaded dirt road around the margins of a temporary mud puddle. When disturbed, the wary adults fly up from the forest floor to land in adjacent bare area of substrate or on the leaves of understory plants.

Superposition eyes are adapted to the dark forest environment in which this species lives.

Superposition eyes are an adaptation to the dark forest environment where this species lives.

I faced a bit of a quandary when I saw this individual—do I collect it as a voucher and studio photograph backup, or do I go ahead and try to get the much more desirable in situ photograph of an unconfined adult in its native habitat. Considering that I had already collected a sufficient number during my earlier trip, I opted for the latter. I am fortunate that I got these two quite acceptable photographs before the adult flashed away in the blink of an eye right after I took the second shot, because I never saw another one the rest of the day or even the trip.  

An interesting feature of O. chrysis is its superposition eyes. In such eyes, each rhabdom (light sensitive unit) in the compound eye receives light through many ommatidial facets. This is in contrast to apposition compound eyes, where each rhabdom receives light from only a single facet. Superposition eyes are designed to increase photon capture, which is an advantage in the dark forest habitats where this beetle prefers to live (Brännström 1999).

Brasiella argentata | Chaco National Park, Argentina

Brasiella argentata (Fabricius, 1801) | Chaco National Park, Argentina

Shortly after photographing O. chrysis, I came upon a small opening where the path was a little wider and sunnier and the soil a little sandier and drier. Immediately I saw the small, zippy flits of the same tiger beetle species I had photographed the previous day on the banks of the Rio Paraná—Brasiella argentata. I could not find in the literature whether this species has superposition or apposition compound eyes, but considering that the species occur in great numbers on sunny river banks and that the few individuals I saw in the forest were in a sunny opening, I’m betting it’s the latter.

I couldn’t help but make another attempt to photograph this species, considering the difficulty I’d had the previous day (and that I wasn’t completely satisfied with any of the photos that I had obtained). More good fortune, despite there being only a few individuals to work with, as I managed to get the above photograph, which I consider far better than any that I already had. These beetles, too, quickly disappeared, and I never saw them again, but knowing I had the photos that I wanted made that okay.

Habitat for Odontocheila chrysis and Brasiella argentata

Quebracho forest habitat for Odontocheila chrysis and Brasiella argentata.

REFERENCES:

Brännström, P. A. 1999. Visual ecology of insect superposition eyes. Unpublished Ph.D. Dissertation, Lund University, 142 pp. [abstract].

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

© Ted C. MacRae 2014

Best of BitB 2013

Welcome to the 6th Annual “Best of BitB”, where I pick my favorite photographs from the past year. Like last year, 2013 was another year of heavy travel. For work I did my annual tour of soybean field sites throughout Argentina during late February and early March, then cranked it up for my own field season with frequent travel to sites in Illinois and Tennessee from May to October. In the meantime I spent a week at company meetings in Las Vegas in August, toured field sites across the southeastern U.S. for two weeks in September, visited Argentina again in October to finalize research plans for their upcoming season, and finished off the travel year by attending the Entomological Society of America (ESA) Meetings in Austin, Texas during November. On top of all this, I managed to slip in two of the best insect collecting trips I’ve had in years, with 10 days in northwestern Oklahoma in early June and another 10 days in California, Nevada, Utah, and Colorado during late August, and I got to play “visiting scientist” during short trips to Montana State University in late July and the Illinois Natural History Survey in late October! Of course, during my brief interludes at home I wasn’t sitting still, giving entomology seminars to several local nature societies and hosting two ESA webinars on insect photography. Needless to say, come December I was more than ready to spend some quite time at home (well, except for hiking most weekends) and am happy to report that I’ve successfully become reacquainted with my family and office mates. It’s a peripatetic life—and I wouldn’t have it any other way!

Okay, let’s get down to business. Here are my favorite BitB photographs from 2013. This year was less about learning new techniques as it was about refining the techniques I’ve found most useful for the style I’ve chosen as a photographer, i.e., hand-held, in situ field shots that (hopefully) excel at both natural history and aesthetic beauty. Links to original posts are provided for each photo selection, and I welcome any comments you may have regarding which (if any) is your favorite and why—such feedback will be helpful for me as I continue to hone my craft. If you’re interested, here are my previous years’ picks for 2008, 2009, 2010, 2011, and 2012. Once again, thank you for your readership, and I hope to see you in 2014!


Tremex columba, female ovipositing | Sam A. Baker State Park, Missouri

Tremex columba female drilling for oviposition into hardwood trunk | Sam A. Baker State Park, Missouri

From Ovipositing Pigeon Horntail (posted 6 Jan). I like this photo for the combination of vibrant, contrasting colors between the wasp and moss-covered wood and the visualization it provides of the remarkable depth to which this wasp will insert its ovipositor into solid wood!


Eurhinus cf. adonis on Solidago chilensis | Chaco Province, Argentina

Eurhinus cf. adonis on Solidago chilensis flowers | Chaco Province, Argentina

From Giving me the weevil eye! (posted 28 Apr). While a little soft, the color combination is pleasing and the pose taken by the beetle almost comically inquisitive.


Helicoverpa gelotopeon feeding on soybean pod | Buenos Aires Prov., Argentina

Helicoverpa gelotopeon feeding on soybean pod | Buenos Aires Prov., Argentina

From Bollworms rising! (posted 30 Mar). This is the first photo of an economic pest that has made one of my “Best of BitB” lists. The two holes in the soybean pod, one with the caterpillar and its head still completely inserted, visualizes how the feeding habits of these insects can so dramatically affect yield of the crop.


cf. Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

cf. Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

From “Blue-sky” tips and tricks (posted 1 July). Insects with a lot of delicate detail and long, thin appendages are especially difficult to photograph against the sky due to wind movement. See how I dealt with the antennae of this delicate lacewing without resorting to the standard black background typical of full-flash macrophotography.


Cicindela scutellaris lecontei x s. unicolor

Cicindela scutellaris lecontei x s. unicolor intergrade | Holly Ridge Natural Area, Stoddard Co., Missouri

From The Festive Tiger Beetle in Southeast Missouri (posted 25 Oct). I like this photo a lot more now than I did when I first took it. Its shadowy feel and the beetle “peering” from behind a leaf edge give a sense of this beetle’s attempts to hide and then checking to see if the “coast is clear”


Batyle suturalis on paperflower (Psilostrophe villosa) | Alabaster Caverns State Park, Woodward Co., Oklahoma

Batyle suturalis on Psilostrophe villosa flowers | Alabaster Caverns State Park, Woodward Co., Oklahoma

From Tips for photographing shiny beetles on yellow flowers (posted 10 Aug). “Bug on a flower” photos are a dime a dozen, but shiny beetles on yellow flowers with natural sky background can be quite difficult to take. All of the techniques for dealing with the problems posed by such a photo came together nicely in this photo.


Agrilus walsinghami | Davis Creek Regional Park, Washoe Co., Nevada

Agrilus walsinghami | Davis Creek Regional Park, Washoe Co., Nevada

From Sunset for another great collecting trip (posted 1 Sep). This photo is not without its problems, with a little blurring of the backlit fuzz on the plant, but the placement of the sun behind the subject’s head and resulting color combination make it my favorite in my first attempts at achieving a “sun-in-the-sky” background with a true insect macrophotograph.


A tiny male mates with the ginormous female.

Pyrota bilineata on Chrysothamnus viscidflorus | San Juan Co., Utah

From Midget male meloid mates with mega mama (posted 8 Nov). Another blue-sky-background photograph with good color contrast, its real selling point is the natural history depicted. with some of the most extreme size dimorphism among mating insects that I’ve ever seen.


Phymata sp.

Phymata sp. on Croton eleagnifolium foliage | Austin, Texas

From ESA Insect Macrophotography Workshop (posted 13 Nov). The oddly sculpted and chiseled body parts of ambush bugs makes them look like they were assembled from robots. Contrasting the body against a blue sky gives a more unconventional view of these odd beasts than the typical top-down-while-sitting-on-a-flower view.


Fourth attempt - holding detached pad up against sky for cleaner background.

Moneilema armata on Opuntia macrorhiza | Alabaster Caverns State Park, Woodward Co., Oklahoma

From Q: How do you photograph cactus beetles? (posted 24 Nov). Photographing cactus beetles requires patience, persistence, long forceps, and strong forearms. Natural sky provides a much more pleasing background than a clutter of cactus pads and jutting spines.


I hope you’ve enjoyed this 2013 version of “Best of BitB” and look forward to seeing everyone in 2014.

Copyright © Ted C. MacRae 2013

A polypipin’ we will go!

A polypipin’ we will go, a polypipin’ we will go
Heigh ho, the dairy-o, a polypipin’ we will go
A polypipin’ we will go, a polypipin’ we will go
We’ll catch a tiger beetle and put him in a vial
And then we’ll let him go (not!)

Okay, maybe my adaptation of the popular children’s song A Hunting We Will Go isn’t the best, but if you want to collect tiger beetles in the genus Tetracha then you’ve got to try the method that my friend Kent Fothergill has dubbed “polypipin’.”

The author polypipin’ in a soybean field in Starkville, Mississippi, September 2013. Photo by Lisa G. Ruschke.

What exactly is polypipin’? Well, it’s when you look for stuff under polypipe—a big plastic tube with holes in it that some farmers use to irrigate their crops. The tube is laid across one end of their field, and when water is pumped into it the water leaks out of the holes along the length of the tube and runs down the furrows between the rows. This is a popular method of irrigation in the Mississippi Delta because the terrain is flat and the equipment costs are much lower than center pivot irrigation systems. Of course, the tube also provides excellent cover for insects and other small critters that live in and around agricultural fields, and these include tiger beetles in the genus Tetracha.

Tetracha carolina under polypipe in a soybean field in Starkville, Mississippi

Tetracha carolina under polypipe in a soybean field in Starkville, Mississippi

I wish I could take the credit, but it was Kent who had the great idea to use polypipin’ as a way to survey for T. carolina (Carolina metallic tiger beetle) in the Mississippi Lowlands (“bootheel”) in southeast Missouri. This is a common species across the southern tier of the United States, but prior to this survey the occurrence of this species in Missouri was not well understood. While a number of specimens had been collected in the bootheel over the years prior to the survey, some regarded Missouri records of the species to be a result of vagrants migrating into the state rather than residents (Pearson et al. 2006). Tiger beetles in the genus Tetracha are nocturnal and take refuge during the day, so they are not often encountered unless one goes at at night with a flashlight. Kent was interested in determining the status of this species in Missouri and had noticed their tendency to take refuge under polypipe—where they could be easily found during the day by simply lifting up the pipe. Rather than give up on sleep, Kent and colleagues surveyed agricultural fields throughout the bootheel by looking under polypipe and demonstrated not only that T. carolina is well established in and a resident of the bootheel, but that it is actually quite abundant and may reside even further north in Missouri than just the bootheel (Fothergill et al. 2011).

Adults are amazingly calm if the polypipe is lifted carefully so as not to disturb them.

Adults are amazingly calm if the polypipe is lifted carefully so as not to disturb them.

I don’t know what it is, but there is just something really fun about polypipin’. Being an agricultural entomologist by day, I have ample opportunity to do a little polypipin’ of my own as I travel across the southern U.S. looking at soybean fields, including this past September when I found myself in fields with polypipe in Arkansas and Mississippi. These photos were taken in Starkville, Mississippi near the Mississippi State University campus, and as has happened in every other case where I’ve looked, I found adults of T. carolina quite abundant underneath the polypipe. Some were found simply resting on the soil surface beneath the pipe, but a great many were observed to have dug burrows under the pipe for added shelter.

Adults often construct burrows underneath the polypipe for additional refuge.

Adults often construct burrows underneath the polypipe for additional refuge.

Polypipin’ works as a survey tool for T. carolina because of that species’ propensity for agricultural fields and other moist, treeless habitats. I’ve not yet found T. virginica (Virginia metallic tiger beetle) under polypipe, but that species is more fond of forested rather than treeless habitats. Perhaps an agricultural field next to forest with polypipe laid on the side adjacent to the forest might produce this species. At any rate, polypipin’ might offer a tool to better define the entire northern distributional limit of T. carolina—all one has to do is look.

REFERENCE:

Fothergill, K., C. B. Cross, K. V. Tindall, T. C. MacRae and C. R. Brown. 2011.Tetracha carolina L. (Coleoptera: Cicindelidae) associated with polypipe irrigation systems in southeastern Missouri agricultural lands. CICINDELA 43(3):45–58 [pdf].

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

Copyright © Ted C. MacRae 2013

Stalking tigers in Argentina

Brasiella argentata

Brasiella argentata | banks of Rio Paraná, Corrrientes, Argentina

Most of you know that I have spent a lot of time in Argentina over the years, and while most of my time there has been for work I have had a fair bit of opportunity to collect insects as well. This includes tiger beetles, and in fact I recall one trip some years ago during which I spent the better part of a week chasing tigers in northeastern Argentina around Corrientes and west into Chaco Province. I think I collected maybe a dozen species or so—some in great numbers and others not, and with the help of tiger beetle expert David Brzoska I’ve managed to put names on most of the material. Despite this, however, I’ve never actually posted any photos of tiger beetles from Argentina here on BitB. I guess the main reason for this is that my efforts to photograph tiger beetles is still a relatively new pursuit (compared to the time that I’ve been going to Argentina), and most of my luck with tiger beetles in Argentina has preceded my time with a camera. The other reason for the delay is that, while I have managed to photograph a few tiger beetles in Argentina, I’ve only recently been able to determine their identity (and you all know how I dislike posting photos of unidentified insects). Well, time to change that, and for this post I am featuring the very first tiger beetle that I was able to photograph in Argentina—the aptly named Brasiella argentata.

Banks of Rio Paraná, habitat for Brasiella argentata.

Banks of Rio Paraná, habitat for Brasiella argentata.

The individuals in this post were photographed on 1 April 2011 during the early part of a week-long visit to Corrientes and neighboring Chaco Province in northern Argentina. Remember, this is the southern hemisphere, so early April is way late in the season and, in this part of Argentina, typically on the back end of a very long dry period. Still, it is far enough north to be borderline subtropical climate, and with the stifling heat it could, for all intents and purposes, have been the middle of summer. I knew tiger beetles could be found along the banks of the Rio Paraná, as I had collected them there during my trip some 10 years previous, so in late morning of my first day after arrival in the city I kitted up and walked down to the river. Sand and mud beaches are not plentiful along the mostly rocky shoreline, and I was perturbed to see the area where I had collected during my last visit had since been “developed.” Nevertheless, I found promising-looking habitat a short distance further north and walked to its moister edges (photo above). I saw nothing at first, but eventually I came to a small, moist drainage where the sand was mixed with more mud, and there they were! It took a little bit of looking, as this species is quite small—adults average only ~7 mm in length, and despite the impression you may get from these photos they are well camouflaged to match the color of the wet, muddy sand and, thus, difficult to see before they take flight and again after they land.

An individual sits long enough to allow a few close, lateral profile shots.

Brasiella argentata is one of the most widely distributed Neotropical species of tiger beetles, occurring from Panama and the West Indies south to Peru and Argentina (Cassola & Pearson 2001). Numerous subspecies have been described from throughout its range, but in truth it seems to actually be a “species swarm” comprised of multiple species, many of which can only be determined by examination of characters contained within the male aedeagus (Sumlin 1979). The genus Brasiella itself, like many others, was until recently considered to be a subgenus of Cicindela, but the distinctiveness of these mostly small (Pearson et al. 2007 refer to them as “Little Tiger Beetles”), cursorial (running) beetles has been recognized in most of the more recent comprehensive treatises (e.g., Cassola & Pearson 2001, Erwin & Pearson 2008). Unlike most of its related genera (subtribe Cicindelina), Brasiella is almost exclusively Neotropical in distribution—only one of its 45 species, B. wickhami, reaches the U.S. in southern Arizona (Pearson et al. 2007).

Brasiella argentata

The only photo I managed looking towards the front of an individual.

If their smallness must be recognized, so must their running abilities. This was one of the most difficult species I’ve ever attempted to photograph, and with those difficulties added to the heat of the day and its “perfect storm” habitat it’s a wonder I got any photographs at all. It was a good half hour before I even got the first photo (top), and another hour and a half of effort was required before I managed to get a selection of photos that included a good, close lateral profile shot (middle). As is often the case with very wary tiger beetles, frontal portraits were almost impossible due to their persistent efforts to flee, so I feel fortunate to have managed the last photo. It’s not as close as I typically like to get, but I am pleased with the composition and also the fact that it shows the species’ truncate labrum—a key character.

REFERENCES:

Cassola, F. & D. L. Pearson. 2001. Neotropical tiger beetles (Coleoptera: Cicindelidae): Checklist and biogeography. Biota Colombiana 2:3–24 [pdf].

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

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

Sumlin, W. D., III 1979. A brief review of the genus Cicindela of Argentina (Coleoptera: Cicindelidae). Journal of the New York Entomological Society 87(2):98–117 [JSTOR].

Copyright Ted C. MacRae 2013

The Festive Tiger Beetle in Southeast Missouri

Cicindela scutellaris lecontei x s. unicolor

Cicindela scutellaris lecontei x scutellaris unicolor (male) | Holly Ridge Conservation Area, Missouri

This past spring I returned to the lowlands of southeastern Missouri in an effort to find and photograph a population of tiger beetles that seems to be unique to the area. The beetles represent Cicindela scutellaris (Festive Tiger Beetle), a widespread species that is common in dry sand habitats across the central and eastern U.S. It is also one of North America’s most polytopic species, with populations in the Great Plains, eastern U.S., Atlantic Coast, southeastern Coastal Plain, and several isolated populations on the western and southwestern peripheries of the species’ range of distribution recognized as distinct subspecies. In Missouri the species is known only from the extreme northwestern, northeastern, and southeastern corners of the state. In all of these areas the populations are found on alluvial sand deposits associated with the Missouri and Mississippi Rivers. Additional sand deposits are found in the areas between these three widely disjunct areas, but curiously the species has not yet been found in them, despite the presence of other species that occupy these same habitats such as Cicindela formosa (Big Sand Tiger Beetle).

Cicindela scutellaris lecontei x s. unicolor

Cicindela scutellaris lecontei x scutellaris unicolor (male) | Holly Ridge Conservation Area, Missouri

The populations in northern Missouri fall well within the distributional range of subspecies C. s. lecontei and are readily assignable to that taxon based on their wine-red coloration and well developed elytral markings. The population in southeastern Missouri, however, cannot be assigned either to that subspecies or to the more southern subspecies C. s. unicolor, which occurs along the southeastern U.S. Coastal Plain and is characterized by solid green coloration and no elytral markings. Individuals from southeastern Missouri are typically green, as in C. s. unicolor, but usually exhibit a distinct wine overtone from C. s. lecontei that varies greatly in its degree of development. Like C. s. lecontei, the elytra are usually marked, but never as strongly as in C. s. lecontei and sometimes not at all (as in C. s. unicolor). The two individuals shown in these photos represent the typical condition—wine blushing and elytral markings only moderately developed; however, more extreme examples can be seen in photos from fall 2008 and spring 2009 (taken during my “point-and-shoot” days, which explains my desire to photograph these beetles again). The intergradation of characters, their variable development, and the apparent presence of a wide disjunction zone between this population and C. s. lecontei to the north suggest to me that it originated from a relatively recent hybridization event between C. s. lecontei and C. s. unicolor—perhaps during the post-glacial hypsithermal that ended some 5,000 years ago.

Cicindela scutellaris lecontei x s. unicolor

Cicindela scutellaris lecontei x scutellaris unicolor (female) | Sand Prairie Conservation Area, Missouri

While I am happier with these photos than I am with those taken earlier, they don’t represent either the full range of variability seen in the population or the most aesthetically pleasing tiger beetle photographs I’ve ever taken. I made two trips to the southeast this past spring, and on each trip I was successful in finding and photographing only a single, very skittish individual—one on a sandy trail through upland forest (Holly Ridge Conservation Area) and the other along the margin of a sand blowout in a native sand prairie remnant (Sand Prairie Conservation Area). I’ll try again this coming spring and hopefully will be able to show some better photographs.

p.s. Can you tell the difference in the type of flash diffuser I used between these two trips? If so, which one do you like better?

Copyright © Ted C. MacRae 2013

INHS Seminar: Tiger Beetles of Missouri

If you are in the Champaign, Illinois area on Tuesday, 29 October 2013, I will be giving a seminar as part of the Illinois Natural History Survey Fall 2013 Seminar Series. I hope to see you there!

My thanks to Dr. Sam Heads for extending to me the invitation and to Jennifer Mui for preparing the very nice poster and attending to travel details.

INHS-Seminar-MacRae_2013-10-29
Copyright © Ted C. MacRae 2013