Insecta

Insects – Collembola, Protura, Diplura, Archaeognatha, Thysanura & Pterygota (winged insects).

Habitat Partitionining in Tiger Beetles

/ Ted C. MacRae / 28 Comments
Cicindela willistoni estancia

Cicindela willistoni estancia. Photo by David Melius.

ResearchBlogging.orgThe latest issue of CICINDELA (December 2009, vol. 41, no. 4) contains an interesting paper by David A. Melius titled, “Post-monsoonal Cicindela of the Laguna del Perro region of New Mexico.” This paper continues a theme that I have touched on a few times in recent posts regarding the partioning of resources by multiple species of tiger beetles utilzing the same habitat. The author reports on the results of two visits to the Laguna del Perro salt lake region of New Mexico (Torrance County) in July 2009, during which time he recorded a total of eight tiger beetle species in the area. As in many other parts of the arid west, tiger beetles in this region are highly dependent upon summer monsoonal rains to trigger adult emergence (Pearson et al. 2006), resulting in multiple species occupying a given habitat during the relatively short post-monsoonal period. However, according to the competitive exclusion principle (Hardin 1960), two species cannot stably coexist in the same habitat and compete for the same resources—one of the two competitors will always overcome the other unless resources are partitioned to avoid competition.

Cicindela willistoni estancia

Cicindela willistoni estancia. Photo by David Melius.

Tiger beetles that occupy the the same habitats employ a variety of mechanisms for avoiding direct competition. One of these is partitioning the environment into different “microhabitats.” One of the earliest reports of this was by noted American ecologist Victor Shelford, who reported that adult tiger beetles on the southern shores of Lake Michigan occupied different habitats from water’s edge to oak forest floor (Shelford 1907). Similarly, Choate (2003) found three sympatric species of tiger beetles in a coastal mudflat region in South Carolina, each of which utilized a different portion of the salt marsh. I myself have noted multiple species occupying the same habitat in Oklahoma’s Salt Plains National Wildlife Refuge, on a coastal salt marsh in Florida, and in the White River Hills of southwestern Missouri.

In the present study, the author noted distinct preferences among the eight species for different microhabitats within and adjacent to the salt flats, including 1) thick, wet mud immediately adjacent to the water, 2) damp, soft sand 10-20 m from the water and devoid of vegetation, and 3) dry to damp sand further away from the water with salt-tolerant plants. Nearby roadside habitats were also noted as an additional microhabitat. The species found and their preferred niches were:

  • Cicindela fulgida rumppii, exclusively in vegetated dry sand areas around the salt flats.
  • Cicindela (Cicindelidia) nigrocoerulea, mostly 10-20m from the water’s edge, a few also in roadside habitat.
  • Cicindela (Cicindelidia) punctulata chihuahuae, exclusively in roadside habitats.
  • Cicindela (Cicindelidia) willistoni estancia, mostly along the water’s edge.
  • Cylindera terricola cinctipennis, exclusively in dry grassy areas away from the water.
  • Ellipsoptera nevadica, exclusively along the water’s edge.
  • Eunota togata fascinans, unvegetated areas near and 10-20m from the water’s edge.
  • Habroscelimorpha circumpicta johnsoni, limited to roadside habitats and vegetated dry sand areas around the salt flats.

These microhabitat partitions can be visualized below. Note that although eight total species were collected, only 2-4 occur within each particular microhabitat and that all eight species were limited to just 1 or 2 microhabitats, resulting in unique species-guilds for each.

Some differences were also noted in species present during the different trips, suggesting that species occurring within the same microhabitat are also utilizing differences in temporal occurrence to further minimize competition. Differences in size among the different species were noted as well – for example, of the four species occurring in the vegetated, dry-damp sand microhabitat, Cylindera terricola is notably smaller and Habroscelimorpha circumpicta notably larger than the others. Since mandible length of adult tiger beetles is highly correlated with preferred prey size (Pearson et al. 2006), this likely results in utilization of different prey, further partioning resources within the different microhabitats.

I thank David A. Melius (Albequerque, New Mexico) for allowing me to include his stunning photographs of Cicindela willistoni estancia in this post.

REFERENCES:

Choate, P. M., Jr. 2003. A Field Guide and Identification Manual for Florida and Eastern U.S. Tiger Beetles.  University Press of Florida, Gainesville, 224 pp.

Hardin, G. 1960. The competitive exclusion Principle. Science 131:1292-1297.

Melius, D. A. 2009. Post-monsoonal Cicindela of the Laguna del Perro region of New Mexico. CICINDELA 41(4):81-89.

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.

Shelford, V. E. 1907. Preliminary note on the distribution of tiger beetles (Cicindela) and its relation to plant succession. Biological Bulletin of the Marine Biological Laboratory at Woods Hole 14:9-14.

Copyright © Ted C. MacRae 2009

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BitB Best of 2009

/ Ted C. MacRae / 22 Comments

In my first post of 2009, I looked back at the photographs I had posted during 2008 and picked some of my personal favorites. I hesitated then to call myself a photographer (and still do), but I at least now have suitable equipment to aid in my progress toward that eventual goal. I have learned much over the past six months in my first attempt at serious insect macrophotography (prioritizing in situ field photographs of unmanipulated subjects as a matter of personal choice).  Through this, I’ve come to realize the following skills to be the most important for success:  

  1. Composition
  2. Understanding lighting
  3. Knowing how to use a flash
  4. Knowledge of the subject

I’ll give myself a “A” in the last of these, but in the other areas I still have much to learn. With this caveat, and for the last post of 2009, I offer the following twelve photographs as my final choices for the 2nd Annual “Best of BitB”:  

Best beetle

Cylindera celeripes (swift tiger beetle), Woodward Co., Oklahoma

From Revisiting the Swift Tiger Beetle – Part 1 (June 30).  A decent enough photograph, especially considering that I’d had my camera for about a month when I took it.  However, the discovery of robust populations of this formerly rare and enigmatic species throughout northwestern Oklahoma (and later also in northwestern Missouri) was the most significant find of the 2009 field season, and this photograph is the best capture of that moment.

Best fly

Stylogaster neglecta, a species of thickheaded fly

From Overlooked, needle-bellied, thick-headed fly (Aug 14).  One of my first good “black background” shots.  The white tip of the abdomen compliments the white flower stamens against the background.

Best “true” bug

Beameria venosa, a prairie obligate cicada

From North America’s smallest cicada (Aug 4).  So many different shades of green with white frosting on the bug’s body.  I tried taking this shot in portrait and it just didn’t work—I liked this landscape shot much better.

Best predator

Promachus hinei (Hines giant robber fly) & Ceratina sp. (small carpenter bee) prey

From Prey bee mine (Sept 14).  Robber flies are immensely photogenic, especially those in the genus Promachus due to their prominent “beards.”

Best camoflauge

Dicerca obscura on bark of dead persimmon

From The “obscure” Dicerca (June 19).  Sparkling and gaudy as specimens in a cabinet, the coloration of many jewel beetles actually helps them blend almost perfectly with the bark of their preferred tree hosts.

Best immature insect

Tetracha floridana (Florida metallic tiger beetle) 3rd-instar larva

From Anatomy of a Tiger Beetle Larva (Oct 22).  “Otherwordly” is invariably the first word that comes to mind when someone sees a tiger beetle larva for the first time.  I was lucky enough to get this one in profile with a nice view of its abdominal hump and its curious hooks.

Best arachnid

Centruroides vittatus (striped bark scorpion)

From A face only a mother could love (Oct 6).  Despite some minor depth-of-field problems with this photograph, I’m fascinated by its “smile.”

Best reptile

Eastern collared lizard (Crotaphytus collaris collaris) adult male

From North America’s most beautiful lizard (July 10).  A simply spectacular lizard—all I had to do was frame it well and get the flash right.

Best wildflower

Spiranthes magnicamporum (Great Plains ladies

From Great Plains Ladies’-tresses (Dec 7).  Few flowers are as photogenic as orchids, even native terrestrials with minute flowers such as this one.  I like the frosty texture of the lip and the starkness of the white flower on the black background.

Best natural history moment

Thermoregulatory behavior by Ellipsoptera hirtilabris (moustached tiger beetle)

From Tiger Beetles Agree—It’s Hot in Florida! (Dec 18). I chose this photo for the classic “stilting” and “sun-facing” thermoregulatory behaviors exhibited by this tiger beetle on a blistering hot day in Florida.

Best closeup

Megaphasma denticrus (giant walkingstick)

From North America’s longest insect (Aug 21).  I haven’t tried a whole lot of super close-up photographs yet.  I liked the combination of blue and brown colors on the black background.

Best Landscape

Sand Harbor Overlook, Lake Tahoe, Nevada

From Sand Harbor Overlook, Nevada (March 23).   My choice for “best landscape” again comes from Lake Tahoe.  This is not a great photo technically—I was still using a point-and-shoot and had to deal with foreground sun.  However, none of the other photos I took during my March visit to the area captivate me like this one.  I like the mix of colors with the silhouetted appearance of the trees on the point.

Copyright © Ted C. MacRae 2009

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Tiger Beetles at Florida’s “Road to Nowhere”

/ Ted C. MacRae / 21 Comments

(continued from the previous post, Tiger Beetles Agree—It’s Hot in Florida!)

During the time that I explored the pine sandhill habitat at Withlacoochee State Forest in Citrus County, I kept close watch for any individuals amongst the dozens and dozens of Cicindela abdominalis (Eastern Pinebarrens Tiger Beetle) that I encountered that might exhibit the deeply pitted rather than smooth elytral surface that would identify it as the closely related Florida-endemic, Cicindela scabrosa (Scabrous Tiger Beetle).  However, no such individuals would be seen (my first tiger beetle failure of the trip), and having already spent more than two hours at the site I decided it was time to move on the the “Road to Nowhere.”

"Road to Nowhere," 11.1 mi S Jena on Hwy 361, Dixie Co., Florida

The Road to Nowhere is a tidal marsh (also known as “coastal salt marsh”) near Steinhatchee in Dixie County (11.1 mi S Jena on Hwy 361).  Although I was not aware of it prior to my August visit, this locality has achieved legendary status among tiger beetle enthusiasts because of the great number of species that can be seen there—as many as 6–10 species in the right season.  Being a coastal wetland with moist, saline substrates, these would include such species as Cicindela trifasciata ascendens (Ascendent Tiger Beetle), Habroscelimorpha severa (Saltmarsh Tiger Beetle), the rarely collected H. striga (Elusive Tiger Beetle), and Eunota togata togata (White-cloaked Tiger Beetle), in addition to Ellipsoptera marginata (Margined Tiger Beetle) and E. hamata lacerata (Gulf Beach Tiger Beetle) which I had already found a few days earlier.  As I found the highway leading to the spot and begain to drive its upper reaches, I looked longingly at the barren sand exposures along the sides of the road thinking that C. scabrosa, already known from the area (Choate 2003) must be there.  However, it was well into the afternoon hours by then, and having already failed to find the species at Withlacoochee State Forest, I decided I should press on and see what the Road to Nowhere had to offer.

Cicindela (Cicindelidia) trifasciata ascendens—Ascendent Tiger Beetle

Almost immediately I began seeing tiger beetles.  The first species I saw was C. trifasciata ascendens—rather common on areas of the flats close to the water’s edge.  I recognized them instantly, as I had not only seen this species some years ago in south Texas, but also in southern Missouri as a lone vagrant (Brown and MacRae 2005).  The dark brown dorsal coloration and thin, sinuous, S-shaped middle maculation are diagnostic for the species (Pearson et al. 2006).  While it was by now late afternoon, the heat of the day had not yet begun to subside, and the beetles were extremely active and flighty.  The difficulty in approaching them closely enough for photographs was exacerbated by the wet, muddy substrate and incessant drone of tenacious mosquitoes intent on breaching my invisible shield of DEET.  Eventually, however, and only due to one decidedly more cooperative individual (above), I succeeded in getting a few shots with which I was happy. 

Habroscelimorpha severa—Saltmarsh Tiger Beetle

Far less common than C. trifasciata ascendens, but equally skittish, was the impressive H. severa.  I have also seen this species before in south Texas, though not in great numbers, and its shiny green surface with maculations reduced to small spots at the middle and rear of the elytra are unmistakealbe.  It was the hardest to approach of the species I saw, and the above (only slightly cropped) photograph is as close as I was able to get (it is also the only photograph from the field session that was good enough and close enough to keep).  This species tends to be most active in the morning and again in the evening, so most of my late-day efforts focused on this species—in fact, it was almost too dark to see by the time I finally quit my attempts at photographing the species.  I brought back one live individual and took some “studio” photographs after I returned home, but I’m still not any happier with them than this lone field shot.

Ellipsoptera hamata lacerata—Gulf Beach Tiger Beetle (reduced maculations)

When I first saw the species represented by the individual in the above photograph, I had not a clue as to its identity—the dark elytra with only a marginal band was unlike anything I would have expected to see.  Quickly thumbing through my “bible” (Pearson et al. 2006), I kept stopping at the plate containing Cicindela marginipennis (Cobblestone Tiger Beetle).  I knew this was impossible, as that species is restricted to several disjunct cobblestone habitats further north.  I collected the specimen for a voucher, keeping it alive for studio photographs, but it wasn’t long before I saw another similar-looking individual.  I decided I must be overlooking something, so after getting photographs and collecting the specimen for another voucher I went back through Pearson.  This time I focused only on the species that could possibly occur here, and realized that it was simply E. hamata lacerata with its normally diffuse middle elytral maculations highly reduced (traces of the middle band can be seen in the photograph).

Ellipsoptera marginata—Margined Tiger Beetle

Ellipsoptera marginata was the most abundant species at this location, and on this day I succeeded in getting a nice photograph of a female with her distinctively downbent elytral apices (see closeup photograph in this post).  This species is very similar to E. hamata, with which it co-occurs along the Gulf Coast of peninsular Florida, but can be immediately recognized by the bent elytral apices (female) or distinct tooth on the underside of the right mandible (male).  Both of these species are distinguished from all other species in the genus by the diffuse middle maculation of the elytra. 

At least two additional species occur at this site, one of which (E. togata) I saw but a single individual of and was unable to photograph, and the other (H. striga) which I did not see.  In fact, the Road to Nowhere is apparently “the” spot for finding the latter species, which occurs predominantly at night and is seen primarily by its attraction to ultraviolet lights.  While I would have liked to stay after dark and setup lights to see this species, I had neither the time nor the equipment to do this.  It may, after all, have been too late in the season anyway—since my visit I’ve heard stories from other tiger beetle aficionados who say the whole area can be filled with collectors from all over the country with their blacklights and bucket traps and someone yelling “striga!” every hour or so.  No such scene developed during my visit, so I suspect my visit was on the late side of the season and that the 5 species I did see represents a pretty good day regardless.  The long drive back to St. Petersburg marked the end of my tiger beetle exploits in Florida, at least for this year.

For another tiger beetling experience at Road to Nowhere, read this post by Doug Taron, who visited the site even later in the season (October).  Although he didn’t see as many tiger beetles, he does provide some interesting details regarding the shady origins of this place.

Photo Details: Canon EOS 50D, ISO 100, 1/250 sec.
Habitat: Canon 17-85mm zoom lens (landscape, 66mm), f/9, natural light.
Insects (except E. marginata): Canon 100mm macro lens (manual), f/22–25, MT-24EX flash w/ Sto-Fen diffusers.
E. marginata: Canon MP-E 65mm 1–5X macro lens (manual), f/16, MT-24EX flash w/ Sto-Fen diffusers.

REFERENCES:

Brown, C. R. and T. C. MacRae. 2005.  Occurrence of Cicindela (Cicindelidia) trifasciata ascendens (Coleoptera: Cicindelidae) in Missouri. Cicindela 37(1–2):17–19.

Choate, P. M., Jr. 2003. A Field Guide and Identification Manual for Florida and Eastern U.S. Tiger Beetles.  University Press of Florida, Gainesville, 224 pp.

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 2009

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Tiger Beetles Agree—It’s Hot in Florida!

/ Ted C. MacRae / 17 Comments

Florida is known for its rich assemblage of tiger beetles—27 species in all, including four endemics (Choate 2003).  However, late summer is generally considered not the best time of year for seeing this diversity, since adult populations of most species begin to wane as the intensity of the summer heat reaches its peak.  I knew the timing of my family vacation in early August might be a bit off; however, considering I had never looked for tiger beetles in Florida before, I remained optimistic that I still might encounter some interesting species.  My optimism was quickly rewarded—in one afternoon of exploring the small coastal preserve just outside the back door of my sister-in-law’s condo, I found Ellipsoptera marginata (Margined Tiger Beetle), its sibling species E. hamata lacerata (Gulf Beach Tiger Beetle), and several 3rd-instar larvae in their burrows that proved to be the Florida endemic Tetracha floridana (Florida Metallic Tiger Beetle).  Good fortune would continue when I made a one-day trip to the interior highlands in a successful bid to find Florida’s rarest endemic, Cicindela highlandensis (Highlands Tiger Beetle), finding also as a bonus the splendidly camouflaged and also endemic Ellipsoptera hirtilabris (Moustached Tiger Beetle).  Five species, including three endemics, in just over a day of searching!  I had one more day to sneak off and do what I love most, and I wanted to make the most of it. 

Pine sandhill habitat, Withlachoochee State Forest—Citrus Tract

Among the suggestions given to me by my colleagues, the most promising-sounding was the “end of the road,” a Gulf Coast salt marsh near Steinhatchee in Dixie County where I was told as many as 6-10 species of tiger beetles could be seen at once.  I didn’t know it at the time, but this particular location has achieved legendary status among tiger beetle enthusiasts (Doug Taron recently wrote about his experience, calling it the Road to Nowhere).  A 200+ mile drive from my base near St. Petersburg, it would take the better part of 5 hours to drive there, and not wanting to put all of my eggs in one basket, I looked for potential stops along the way.  About midway along the drive was Withlacoochee State Forest, where one of my colleagues had told me I might still find the fairly widespread Cicindela abdominalis (Eastern Pinebarrens Tiger Beetle) and its close relative, C. scabrosa (Scabrous Tiger Beetle)—the fourth Florida endemic.  My plan was to leave early in the morning and spend a few hours at Withlacoochee before driving the rest of the way to finish out the day at Steinhatchee. 

"Stilting" by Cicindela abdominalis (Eastern Pinebarrens Tiger Beetle)

It took some time to find my bearings upon arriving, but after some discussion with the decidedly forestry-oriented staff at the headquarters, it seemed that the Citrus Tract was where I wanted to be.  I was looking for the sand barren and pine sandhill habitats that these species require, and the staff’s description of the northern edge of the tract as having lots of sand and “not very good for growing trees” suggested this might be the place.  Pine sandhill (also called “high pine”) is a pyrophytic (fire-dependent) plant community characterized by sandy, well-drained soils, a widely-spaced longleaf pine (Pinus palustris) and turkey oak (Quercus laevis) canopy, and an herbaceous layer dominated by wiregrass (Aristida stricta).  I quickly found such habitat in the area suggested, and it wasn’t long before I found the first of the two species—C. abdominalis—rather commonly along a sandy 2-track leading through the area.  For those of you who see a distinct resemblance of this species to the rare C. highlandensis that I highlighted from my trip to the central highlands, this is no coincidence.  Cicindela abdominalis is very closely related to that species, the latter distinquished by an absence of flattened, white setae on the sides of the prothorax and the abdomen and by the highly reduced or absent elytral maculations (Choate 1984).  Dense white setae and distinct apical elytral maculations are clearly visible in the individuals shown in these photographs. 

Stilting is often accompanied by "sun-facing" for additional thermoregulation

It was a blistering hot day (just as every other day on the trip had been so far), and it wasn’t only me who felt that way.  Tiger beetles, of course, are ectothermic and rely upon their environment for their body temperature.  Despite this, they are able to regulate body temperatures to some degree by using a range of behavioral adaptations intended to mitigate the effects of high surface temperatures and intense sunlight.  The photos above show one of these behaviors, known as stilting.  In this behavior, the adult stands tall on its long legs to elevate its body above the thin layer of hotter air right next to the soil surface and as far off the sand as possible (Pearson et al. 2006).  As the heat of the day intensifies and the zone of hot air at the soil surface broadens, stilting alone may be insufficient to prevent overheating. When this happens, the beetles combine stilting with sun-facing, a behavior in which the front part of the body is elevated with the head oriented towards the sun. This position exposes only the front of the head to the sun’s direct rays, thus minimizing the body surface area exposed to incident radiation.

Stilting and sun-facing by Ellipsoptera hirtilabris (Moustached Tiger Beetle)

I was also fortunate to have another chance at photographing the beautiful and marvelously-camouflaged Ellipsoptera hirtilabris (Moustached Tiger Beetle), which, in similar fashion to C. highlandensis, I found co-occurring with C. abdominalis in rather low numbers. As before, they were extremely wary and difficult to approach, especially in the extreme heat of the day, and all of my best efforts to get a good shot of the species in its “classic” pose were frustrated. The photo above was about as close as I could get to any of these beetles when they were out in the open before they would flee; however, it nicely demonstrates the use of stilting combined with sun-facing during the hottest part of the day.

"Shade seeking" is another behavioral response to intense heat.

Another behavioral response to extreme heat is shade-seeking—adults may either remain active, shuttling in and out of shaded areas, or avoid exposed areas altogether and become inactive.  One thermoregulatory behavior for extreme heat that I did not observe was daytime-burrowing, in which adults construct temporary shallow burrows during the hottest hours of the day. Although I did not observe this behavior by either species at Withlacoochee, I have seen it commonly among several species in sandy habitats here in Missouri and in the Sandhills of Nebraska (e.g., Cicindela formosa, Cicindela limbata, Cicindela repanda, Cicindela scutellaris, Cicindela tranquebarica, Ellipsoptera lepida).

There was one disappointment on the day—I did not see C. scabrosa.  However, I still had the “end of the road” to explore, so I remained happy with the now six species I had encountered and optimistic about finding additional species later in the day… 

Photo Details: Canon EOS 50D, ISO 100.
Habitat: Canon 17-85mm zoom lens (landscape, 17mm), 1/100 sec, f/10, natural light.
Insects: Canon 100mm macro lens (manual), 1/250 sec, f/16–18 (C. abdominalis) or f/20–22 (E. hirtilabris), MT-24EX flash w/ Sto-Fen diffusers.

REFERENCES: 

Choate, P. M., Jr.  1984.  A new species of Cicindela Linnaeus (Coleoptera: Cicindelidae) from Florida, and elevation of C. abdominalis scabrosa Shaupp to species level.  Entomological News 95:73–82.

Choate, P. M., Jr. 2003. A Field Guide and Identification Manual for Florida and Eastern U.S. Tiger Beetles.  University Press of Florida, Gainesville, 224 pp.

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 2009

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Do You Have “An Inordinate Fondness”?

/ Ted C. MacRae / 23 Comments

Last week I mentioned that I had been thinking about starting a blog carnival devoted exclusively to beetles.  Actually, I’ve been thinking about it for some time now, but following up on the idea apparently needed a catalyst.  That catalyst came last week when Amber Coakley and Jason Hogle announced the debut of House of Herps—another specialty nature blog carnival, focusing on reptiles and amphibians.  I supported the idea of a herp carnival when Amber first mentioned it, and she responded to that support by actually going out and doing it!  Amber penned a guest post on Nature Blog Network called House of Herps: The Origin Story that described in fascinating detail the process that she and Jason went through in creating a new blog carnival.

Well, the story that Amber told and the details she provided were enough to convince me that I could do it, and the many comments I got on my post last week mentioning what I was thinking about convinced me that I should do it.  The screenshot above is a first peek at the home site of nature blogging’s newest carnival, An Inordinate Fondness (AIF)—the monthly blog carnival devoted to beetles.  The name honors J.B.S. Haldane’s perhaps apocryphal riposte when queried about what his studies of nature’s diversity had taught him about the Creator (a quote made even more famous by the breathtakingly beautiful An Inordinate Fondness for Beetles, written and illustrated by my friends and colleagues, Drs. Charles L. Bellamy and Arthur V. Evans).  Some of you may recall that the alternate name, “Beetle Bacchanalia,” also received strong support (even edging out AIF in raw vote count).  However, while both names imply unbridled passion, I eventually decided that AIF better described the nature of that passion and added historical context.

Even though the AIF website is up and running, the first issue is not scheduled to appear until mid-February.  The reasons for this are primarily personal—I’m already slated to host House of Herps #2 on Jan 18 and Circus of the Spineless #47 on Feb 1 (does this make me a carnival hosting slut?).  There are also still a few things I’d like to have in order before AIF debuts—primarily a badge.  Seabrooke Leckie has offered some help in this regard, and I’ve got a few ideas of my own, but please don’t hesitate to let me know if you’ve got ideas as well.  In addition, I’m hoping this will be the start of getting the word out so that by the time Feb 15 (first issue submission due date) rolls around there will be enough submissions on hand to make the inaugural edition a memorable one.  Lastly, I’m hoping to recruit volunteers for hosting future editions—AIF will be a migrating carnival, dependent upon a community of science and natural history bloggers to keep it going.

My deepest thanks to Amber, Jason, Seabrooke, and Mike Bergin for their very helfpul and supportive comments.

Copyright © Ted C. MacRae

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Cicadetta kansa in Oklahoma

/ Ted C. MacRae / 18 Comments

Photo details: Canon 100mm macro lens on Canon EOS 50D, ISO 100, 1/250 sec, f/14, MT-24EX flash 1/4 power w/ Sto-Fen diffusers.

Another of the insects that I saw this past June at Four Canyon Preserve in northwestern Oklahoma was this small cicada, Cicadetta kansa. Though not as small as the diminutive Beameria venosa (see North America’s smallest cicada), their barely audible call – a soft buzz – makes them even more difficult to notice.  I only realized what they were after noticing something odd about the small, green “grasshoppers” that flitted in front of me as I walked through the mixed shortgrass prairie.  They didn’t quite fly “right” and landed delicately within the grass rather than crashing into it clumsily.  Even after realizing that they weren’t grasshoppers, it was difficult to say what they were at first due to their wariness and lime green coloration that helped them blend marvelously into their grassy surroundings.  A few sweeps of the net solved that problem, and I discovered what was at the time the smallest and most beautiful cicada I had seen to that point (Beameria venosa took both honors later that month in the Loess Hills of northwestern Missouri).

Despite being the only world-wide genus of cicadas, Cicadetta is represented in the U.S. by only two species—C. kansa and C. calliope.  In addition to its pale green coloration, C. kansa is distinguished from C. calliope by having only 4 or 5 apical cells in the hind wing (6 in C. calliope).  Cicadetta kansa occurs from Texas north to South Dakota, while C. calliope is found from Texas to Florida and northwards to Iowa, Ohio and New Jersey.  Little is known about the biology of Cicadetta kansa; however, presumably it is similar to that of C. calliope, which emerges and lays eggs in late spring.  Eggs hatch by late summer, at which time the nymphs burrow into the ground again begin feeding on the roots of grasses.  This feature of their biology protects them from the negative impacts of managed spring and fall burns, and indeed C. calliope is known to increase in prairies that are managed by such burns.  This is in contrast to other prairie cicadas (genus Tibicen), which overwinter as eggs in the above-ground portion of grasses and, thus, are negatively impacted by fall and spring burns.

A number of websites are dedicated to these charismatic insects; however, Cicada by Andy Hamilton at the Canadian National Collection of Insects, Arachnids and Nematodes is the most informative and comprehensive that I’ve found.

Copyright © Ted C. MacRae

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A bid for OpenLab

/ Ted C. MacRae / 14 Comments

I’m going to do something I’ve not yet done before—ask for your support.  OpenLab is an annual compilation of the year’s best science-blog writing, as determined by a panel of judges, and the closing date for submissions for 2009 is December 1st—this coming Tuesday.  I’ve vacilated about whether to throw my hat into this ring—the world of science blogs is a crowded place with many erudite writers, and although science is my profession, the science that I write about is purely avocational.  Whether my particular brand of science writing can compete with that of the true academicians that seem to dominate the competition remains to be seen.  Nevertheless, I am willing to put my ego on the line and give it a shot.  If you have seen anything in the past year (since December 1, 2008) here at Beetles in the Bush that you consider exemplary, please consider submitting it.  Feel free to search the sidebar archives (“Taxa,” “Tags” or “Life History”), browse the site Contents, or select from the following list of my own personal favorites (arranged chronologically):

So I don’t get accused of asking but not giving, I leave you with this photograph of a group of Kern’s flower scarabs (Euphoria kernii, family Scarabaeidae) congregated in the flower of large-root prickly pear cactus (Opuntia macrorhiza, family Cactaceae).  Photographed this past June at Four Canyon Preserve in northwestern Oklahoma, this common, extremely variable species (ranging from all black to black and white to black and yellow to nearly all yellow) can be found throughout the southern Great Plains, where it congregates tightly in flowers of Opuntia , pricklypoppy (Argemone spp., family Papaveraceae), thistle (Cirsium spp., family Asteraceae), and yucca (Yucca spp., family Liliaceae).

Photo details: Canon 100mm f/2.4 macro lens on Canon 50D (manual mode), ISO-100, 1/250 sec, f/16, diffused MT-24EX flash.

Copyright © Ted C. MacRae 2009

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A “Really” Big-headed Tiger Beetle

/ Ted C. MacRae / 4 Comments

Megacephala megacephala 3rd-instar larva. Photo © Artur M. Serrano.

In my recent summary of the latest issue of the journal Cicindela, I included a scan of the cover of that issue and its stunning image of the 3rd-instar larva of Megacephala megacephala¹ from Africa.  This otherwordly-looking, four-eyed beast was photographed with jaws agape at the entrance to its burrow in Guinea Bissau by Dr. Artur M. Serrano (University of Lisbon, Portugal).  I was grateful for his permission to post a scan of this spectacular image; however, he did even better and sent me high-resolution images of not only the larva (above) but the adult (below) as well.  This species is one of 13 assigned to the genus—presently restricted to Africa (though not always, see discussion below), where they are usually found in savanna-type habitats and are active during the crepuscular and nocturnal periods (Werner 2000).

¹ An example of a tautonym, i.e. a scientific binomen in which the genus and species names are identical. Familiar tautonymic binomina include the gorilla (Gorilla gorilla), green iguana (Iguana iguana), and European toad (Bufo bufo). Tautonyms are expressly prohibited in plant nomenclature (see Article 23.4 of the International Code of Botanical Nomenclature) but are permitted and, in fact, quite common in zoological nomenclature; Wikipedia lists 51 mammals, 82 birds, 15 reptiles & amphibians, 54 fish, and 33 invertebrates (though not Megacephala megacephla!).

Megacephala megacephala adult. Photo © Artur M. Serrano.

For those of you who see a strong resemblance by this species to another tiger beetle I featured recently, Tetracha floridana (Florida Metallic Tiger Beetle), this is not merely a coincidence.  Megacephala and Tetracha are quite closely related, and in fact the two genera, along with a handful of other closely related genera, are at the center of one of the longest-standing disputes in tiger beetle taxonomy (Huber 1994).  The genus Megacephala was established by Latreille (1802) for the species pictured here (originally described as Cicindela megacephala Olivier).  As additional taxa were found in Africa, Australia and the Western Hemisphere and assigned to Megacephala, several workers attempted to divide the genus into multiple genera (with New World taxa being assigned to Tetracha and a few other mostly South American genera); however, there was little agreement on how these genera should be defined and on what characters they should be based.  The debate was effectively swept under the rug in the early 20th Century when Walter Horn, one of the most influential cicindelophiles of all time, accepted a monotypic Aniara based on the strange South American species A. sepulcralis but reunited the world’s remaining taxa within the single genus Megacephala in his world catalogue (Horn 1910).  Horn’s use of Megacephala as a catch-all genus was followed by subsequent workers for almost a full century until Huber (1994) once again proposed restricting Megacephala to certain of the African species and resurrecting the genus Tetracha for the bulk of the New World fauna.  He also urged additional analyses to resolve the status of the remaining generic names and their composition, which subsequently saw increasing use as subgenera of Megacephala² and later as genera.

² Thus, as type-species for the genus, the species featured here became known as Megacephala (Megacephala) megacephala (Werner 2000)—a triple tautonym that translates to the “Big-headed, Big-Headed, Big-Headed” tiger beetle!  Perhaps it’s best that I’m not an African tiger beetle specialist; I probably would have been unable to resist the temptation to resurrect M. senegalensis and assign it as a subspecies of M. megacephala, just so I could refer to the nominate form as Megacephala (Megacephala) megacephala megacephala!

The reversal of Horn’s concepts now appears to be complete, with all seven former subgenera of Megacephala formally being accorded full generic status (Naviaux 2007). This classification is strongly supported by molecular analysis of nuclear 18S and mitochondrial 16S and cytochrome oxidase gene sequences (Zerm et al. 2007), with the resulting dendrogram indicating three monophyletic clades corresponding to the African/Palearctic (Megacephala and Grammognatha, respectively),  Western Hemisphere (Aniara, Metriocheila, Phaeoxantha and Tetracha) and Australian (Australicapitona and Pseudotetracha) genera³.  The African/Palearctic clade was found to occupy a basal position in the tree, while the Western Hemisphere and Australian clades were more derived.  These data support the hypothesis that the early evolution of the megacephalines took place during the break-up of the ancient Gondwana megacontinent, which began about 167 million years ago (middle Jurassic period) and sequentially disconnected Africa from South America and Australia.

³ One striking deviation from the current classification, however, was the support for nesting the single Aniara species within Tetracha, a placement that renders Tetracha paraphyletic and, thus, requires either its division into multiple genera or the sinking of Aniara as a distinct genus. The support for this placement was quite strong and mirrored the results of a broader molecular phylogenetic study of tiger beetles based on full-length 18s RNA data (Galian et al. 2002). The authors concede that this puzzling placement is not corroborated by numerous morphological, ecological and ethological characters that distinguish Aniara from all known Tetracha species.

REFERENCES

Galián J., J. E. Hogan and A. P. Vogler. 2002. The origin of multiple sex chromosomes in tiger beetles. Molecular Biology and Evolution 19:1792–1796.

Horn, W.  1910.  Coleoptera Adephaga, Fam. Carabidae, Subfam. Cicindelinae.  In P. Wytsman (editor).  Genera Insectorum.  Fascicle 82a.  Desmet-Vereneuil, Brussels, Belgium, pp. 105–208.

Huber, R. L.  1994.  A new species of Tetracha from the west coast of Venezuela, with comments on genus-level nomenclature (Coleoptera: Cicindelidae).  Cicindela 26(3/4):49–75.

Latreille, P. A. 1802. Histoire Naturelle, Générale et Particulière des Crustacés et des Insectes. Paris: F. Dufart 3 xii 13 + 467 pp.

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

Werner, K.  2000.  The Tiger Beetles of Africa (Coleoptera: Cicindelidae).  Volume 1.  Taita Publishers, Hradec Kralove, Czech Republic, 191 pp., 745 figures.

Zerm, M., J. Wiesner, J. Ledezma, D. Brzoska, U. Drechsel, A. C. Cicchino, J. P. Rodríguez, L. Martinsen, J. Adis and L. Bachmann.  2007.  Molecular phylogeny of Megacephalina Horn 1910 tiger beetles (Coleoptera: Cicindelidae).  Studies on Neotropical Fauna and Environment 42(3):211–219.

Copyright © Ted C. MacRae 2009

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