Cicindela formosa pigmentosignata (the “reddish-green sand tiger beetle”)

In my last post, I discussed Cicindela scutellaris rugata, the so-called “wrinkled fetiger beetle” (Erwin & Pearson 2008)—one of several geographically restricted subspecies of a more widespread and geographically variable species. This was not the only goal of the day, however, as I was also hoping to see a second geographically restricted subspecies—Cicindela formosa pigmentosignata, the “reddish-green sand tiger beetle (Erwin & Pearson 2008). The parent species of these two species show remarkably similar patterns of distribution, habits, and diversification—both occur most commonly as nominotypical subspecies in the Great Plains but have also expanded eastward and diverged there and around the periphery of their range into a number of distinctive subspecies; both favor deep, dry sand habitats without standing water; and both exhibit a “spring/fall” life history where sexually immature adults emerge in fall, pass the winter in burrows, and emerge again in spring ready to mate and lay eggs. In fact, these two species are so inextricably linked to each other that throughout most of their range, where one is found usually so is the other, and where one is represented by a distinctive subspecies so is the other. The main exception to this is in the far southeastern U.S., where C. scutellaris has established as the subspecies C. s. unicolor in sandy forest openings but C. formosa has not.

Cicindela formosa pigmentosignata

Cicindela formosa pigmentosignata W. Horn, 1930—Van Zandt Co., Texas

Cicindela formosa currently contains five recognized subspecies (Pearson et al. 2006)—the nominate subspecies (big sand tiger beetle) found west of Missouri (and which I’ve photographed in Nebraska), C. f. generosa (eastern sand tiger beetle) found in Missouri (photographed here and here) and further east, C. f. gibsoni (Gibson’s sand tiger beetle) found in Colorado and Manitoba (the consubspecificity of these two widely disjunct populations currently being the subject of debate), C. f. rutilovirescens (Mescalero sand tiger beetle) found in New Mexico (and which I’ve seen and collected a single specimen, but before my days as a photographer), and this one: C. f. pigmentosignata from eastern Texas and neighboring areas of Arkansas and Louisiana. Rumpp (1986) proposed that the parent species, C. formosa, radiated in central North America, adapting to barren sand conditions, dispersing along sand hills and major river systems into other areas, and ultimately diverging into the currently recognized subspecies.

Cicindela formosa pigmentosignata

Adults commonly exhibit “shade seeking” behavior during the hotter parts of the day.

As with C. s. rugata, I found this subspecies in a couple of old, rural cemeteries in eastern Texas (Sand Flat Pioneer Cemetery in Henderson Co. and Morris Chapel Cemetery in Van Zandt Co.)—the photos shown here are from the second locality and were taken during the afternoon in the heat of the day. Because of this the beetles were quite wary and difficult to approach, but they also exhibited much more photogenic behaviors related to thermoregulation such as stilting and shade seeking. As I stalked the beetles through the deep, dry sand trying to get photographs, I was reminded yet again of why I love this species of tiger beetle so much—their bulk; their bulging eyes; their long, looping escape flights that end with a comical bounce and tumble, only to end up on their feet and facing their pursuer. These beetles are loaded with personality and behavioral charisma, and this particular subspecies with its brilliant and almost completely immaculate reddish-purple elytra and vividly contrasting blue-green legs and sides was an especially treasured sight to behold (especially after failing in my first attempt to find it back in 2012).

Cicindela formosa pigmentosignata

“Stilting” is another thermoregulatory behavior designed to raise the body up off the hot sand.

I am reasonably satisfied with these photos, although I would have liked to have gotten at least one without some part of the beetle obscured by foliage. That said, I now prefer some foliage in my tiger beetle photos, as I think it adds a bit of perspective, and when it is in the context of thermoregulatory behavior so much the better. And so, having now gotten good field photographs of this subspecies I am motivated more than ever to return to the Mescalero Sand Dunes in New Mexico and find and photograph C. f. rutilovirescens to complete my photographic “collection” of subspecies of the sand tiger beetle. Of course, by then I will probably be sufficiently dissatisfied with my existing photos of the other subspecies (already so with those of C. f. gibsoni due to excessively cropped compositions) that I will want to do the same with each of them as well. Such is the curse—and the blessing—of the insect photographer!

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].

Rumpp, N. L. 1986. Two new tiger beetles of the genus Cicindela from western United States (Cicindelidae: Coleoptera). Bulletin of the Southern California Academy of Sciences 85(3):139–151 [Biodiversity Heritage Library pdf].

© Ted C. MacRae 2016

Posted in Coleoptera | 6 Comments

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 Sand Flat 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

Posted in Cicindelidae, Coleoptera | Tagged , , , , , | 9 Comments

The “black bringer of light”

During last year’s Fall Tiger Beetle Collecting Trip, I spent a day visiting cemeteries in the Post Oak Savannah region of northeastern Texas to look for tiger beetles associated with open sand in and around the cemeteries. It had been a good day, and I thought I would try to squeeze in one more visit to a locality I had visited earlier in the day. By the time I arrived at Sand Flat Cemetery in Henderson Co., however, it was almost 6 p.m.—the sun was still up, but the shadows were long and no tiger beetles were found. Not all insects, however, are so quick to turn in as tiger beetles, so I lingered for awhile and eventually found an area where several large bee flies (family Bombyliidae) were seen flying and briefly perching on the ground or the tips of plains snakecotton (Froelichia floridana). Since this was the last stop of the day and there were no tiger beetles to demand my attention, I spent a fair bit of time trying to photograph these very skittish flies and ended up with photos of two different individuals that I was happy with.

Poecilanthrax lucifer

Poecilanthrax lucifer (Fabricius, 1775)—Sand Flat Cemetery, Henderson Co., Texas

Alex Harman was the first to suggest they might represent the species Poecilanthrax lucifer based on a quick iPhone photo that I posted on Facebook, a hunch that was eventually confirmed by Bishop Museum dipterist Neil Evenhuis based on these photos sent to him by e-mail. Poecilanthrax  is a strictly North American (sensu lato) genus that, at the time of its last revision by Painter & Hall (1960), contained 35 species. Although distributed from Canada south through Central America, the greatest abundance of species and individuals is found in the Great Basin region, and, so far as is known, the larvae develop as parasites inside caterpillars of various cutworms and armyworms (family Noctuidae).

Poecilanthrax lucifer

Adults were found perching on the flowers of plains snakecotton (Froelichia floridana)

Poecilanthrax lucifer is one of the more widely distributed species in the genus, occurring predominantly in the West Indies and southern Gulf States but also ranging south into Central America and north into Arkansas and southern Illinois. It is distinguished from other species in the genus by its conspicuous black and yellow tomentose (densely covered with short matted woolly hairs) crossbands on the abdomen and the bases of the larger veins yellow or tan and contrasting with the remainder of the wing color pattern.

Poecilanthrax lucifer

Black and yellow tomentose abdominal bands and yellow/tan larger wing veins distinguish this species.

Like other species in the genus, P. lucifer is known to parasitize noctuid caterpillars, having been reared from fall armyworm (Spodoptera frugiperda) and exhibiting parasitism rates of up to 25%. This species is unique in the genus, however, in that it has also been reported as a hyperparasite (parasite of a parasite) of Myzine haemorrhoidalis (family Tiphiidae), a primary parasite of white grubs (genus Phyllophaga) in Puerto Rico. The life histories of many species in the genus remain unknown, however, so perhaps other species in the genus will eventually be found to act as hyperparasites as well. All species of Poecilanthrax appear to be univoltine (one generation per year) in natural habitats; however, P. lucifer and a few others that frequent agricultural areas have been found to become facultatively bivoltine or multivoltine due to the extended seasonal availability of pest caterpillars that often occur in these situations.

Poecilanthrax lucifer

“Satanic deadly disease” or “black bringer of light”?

The scientific name of Poecilanthrax lucifer is perhaps one of the more ominous sounding names I’ve encountered. “Anthrax” is, of course, commonly associated with the often deadly infectious bacterial disease caused by Bacillus anthracis, while “lucifer” is none other than Satan himself! However, I suspect that the name of the genus refers not to the disease, but rather its original Greek meaning of “charcoal” in reference to the often black color of the adult flies. Likewise, the original Latin meaning of the word “Lucifer” is “morning star” or “Venus” when used as a noun and “light-bringing” when used as an adjective—only after a series of corruptions through repeated transcriptions and translations of the Bible did it become a name synonymous with the Devil. Thus, a name that could be interpreted as “Satanic deadly disease” might actually mean the “black bringer of light”.

REFERENCE:

Painter, R. H. & J. C. Hall. 1960. A monograph of the genus Poecilanthrax (Diptera: Bombyliidae). Kansas State University of Agriculture and Applied Science, Agricultural Experiment Station, Technical Bulletin 106, 132 pp. [HathiTrust pdf].

© Ted C. MacRae 2016

Posted in Bombyliidae, Diptera | Tagged , , , , , , , | 6 Comments

Fun with eucraniines!

During my February/March 2015 visit to Argentina, I had the opportunity to travel to west-central provinces of San Juan and San Luis with Federico Ocampo for a weekend of insect collecting. Up to that point most of my collecting in Argentina had been limited to the northeastern provinces (Chaco, Corrientes, and Misiones), so I was excited for the chance to explore a radically different biome. West-central Argentina represents a transition zone from the flat, wet, treeless plains of the Humid Pampas in east-central Argentina (Buenos Aires, Santa Fe, and Córdoba Provinces) to the massive Andes Mountains running along the western edge of South America. This area is home to the Monte, a desert biome characterized by volcanic sediments, piedmont plains, large mountain blocks and dry salt lakes. Conditions in the Monte are generally more hospitable than in the neighboring Atacama and Patagonian Deserts lying north and south of the Monte, respectively. As a result, the flora and fauna in the Monte is relatively rich and characterized by a diversity of shrubs, grasses, and cacti.

Dunas de Encón

Encón Dunes, San Luis Province, Argentina

Of the several sites we visited in the area, the most remarkable was “Las Dunas de Encón” (the Encón Sand Dunes) in San Luis Province. Belonging to a larger system covering some 250,000 hectares—the largest in South America (and, thus, sometimes called the “Argentinian Sahara”)—the dunes are thought to have formed some 100–200K years ago as a result of dry conditions brought on by Quaternary glaciations. I find sand dune systems endlessly fascinating due to their unique and often endemic plants and animals and have visited many systems in North America (Bruneau, Coral PinkGlamisGreat, Medora, St. Anthony, and others), but this was the first sand dune system I’ve had the opportunity to see outside of the U.S. Federico, a scarab specialist, shares that fascination and has, in fact, described a number of species in the scarabaeine tribe Eucraniini—endemic to South America—that utilize these very sand dunes (Ocampo 2005, 2007, 2010). He was hoping one or more of them might be out and about; I was hoping to see anything, really.

Host for Lampetis spp.

Parkinsonia praecox? – adult host plant for Lampetis baeri and L. corinthia.

One of the first plants that caught my attention was a woody, fabaceous shrub that looked very much like what I would have previously called Cercidium, now Parkinsonia, and which after a bit of digging I conclude is likely Parkinsonia praecox. Woody, fabaceous shrubs in desert habitats are a sure bet to host jewel beetles, so I began paying special attention to each shrub as I wandered by. It wasn’t long before I saw a large, brilliant metallic green jewel beetle sitting on an outer branch of one of the shrubs—it was one of the most beautiful jewel beetles I have ever seen out in the field with my own eyes! I managed to catch it, and over the next few hours I collected not only several more of this species but also several individuals of an even larger, more somber-colored species. I was able to identify them as Lampetis baeri (Kerremans, 1910) and L. corinthia (Fairmaire, 1864), respectively, when I compared them to material in the collections at Fundacion Miguel Lillo, Instituto de Entomologia, Tucuman, Argentina [IFML]) during my visit there the following week (see photos below).

Lampetis baeri (Kerremans, 1910)

Lampetis baeri (Kerremans, 1910) [IFML]

Lampetis corinthia (Fairmaire, 1864)

Lampetis corinthia (Fairmaire, 1864) [IFML]

As a jewel beetle enthusiast, you would think that was the highlight of my day. In fact, the fun had only started. For a time after our arrival, Federico pointed out burrows likely made by eucraniine adults, but we didn’t see any evidence of activity at first. It wasn’t long, however, before we found the first adult—a fine Eucranium beleni Ocampo, 2010, the largest of the three species occurring at this site (about the size of our North American Deltochilum). One of the more obvious features of eucraniines is their enormously enlarged forelegs and pronotum to hold the musculature required to carry—that’s right, carry!—provisions to the larval burrow (in contrast with the more commonly seen habit among members of the subfamily of using the hind legs to push provisions to the burrow). This unusual morphology gives these beetles not only an amusing, shuffling gait but also a rather comical method for turning themselves upright (as seen in this video narrated by Federico). There are other dung beetles that pull, rather than push, larval provisions (e.g., Sisyphus spp., which stand on highly elongate hind legs and walk backwards while pulling the dungball), but eucraniines seem to be the only ones that actually lift provisions off the ground to carry them. In the case of E. beleni, this involves carrying pieces of dung with the forelegs held out in front of the head while walking forward on the middle and hind legs (Ocampo 2010). I didn’t get to see that behavior with E. beleni, but I did see it with one of another of the eucraniines we found that day (see below). In the E. beleni photo below, note the brushy middle and hind tarsi—an adaptation for walking on loose sand.

Eucranium belenae

Eucranium belenae Ocampo, 2010 walks on its middle/hind legs while holding its forelegs aloft.

Eucranium belenae burrow

Eucranium belenae burrow plugged with a piece of dung.

The second species in the group that we encountered was Anomiopsoides cavifrons (Burmeister, 1861). This species is much smaller than E. beleni (about the size of a large Onthophagus), and unlike E. beleni—and, in fact, most other dung beetles—the larvae of A. cavifrons develop on plant matter rather than dung. Both males and females provision the larval burrows with pieces of plant debris that they pick up with their front legs and carry back to the burrow while walking on their other four legs. This rather amusing video shows a male bringing a piece of debris back to his burrow, then exiting to find and retrieve another piece of debris to bring back to the burrow. The molar region of their mandibles is heavily sclerotized for masticating the plant fibers in preparation for the larvae. There are a couple of other species in the tribe that opportunistically include plant matter in their diet, but A. cavifons seems to be the only one known to utilize dry plant matter in desert habitats almost exclusively (Ocampo 2005). Anomiopsoides cavifrons was far more abundant in the dunes than E. beleni, and by early to mid-afternoon they were encountered with such regularity that I stopped even looking at them.

Anomiopsoides cavifrons male at burrow

Anomiopsoides cavifrons (Burmeister, 1861) male at burrow entrance.

We also were fortunate to see a few individuals of the third species known from these dunes, Anomiopsoides fedemariai Ocampo, 2007. This species is intermediate in size between the extremes represented by E. beleni and A. cavifrons and utilizes pellets of the plains viscacha (Lagostomus maximus), a species of rodent in the family Chinchillidae, for food (Ocampo 2007).

REFERENCE:

Ocampo, F. C. 2005. Revision of the southern South American endemic genus Anomiopsoides Blackwelder, 1944 (Coleoptera: Scarabaeidae: Scarabaeinae: Eucraniini) and description of its food relocation behavior. Journal of Natural History 39(27):2537–2557 [pdf via DigitalCommons].

Ocampo, F. C. 2007. The Argentinean dung beetle genus Anomiopsoides (Scarabaeidae: Scarabaeinae: Eucraniini): description of a new species, and new synonymies for A. heteroclytaRevista Sociedad Entomología Argentina 66(3–4):159–168 [pdf via SciELO Argentina].

Ocampo, F. C. 2010. A revision of the Argentinean endemic genus Eucranium Brullé (Coleoptera: Scarabaeidae: Scarabaeinae) with description of one new species and new synonymies. Journal of Insect Science 10:205, available online: insectscience.org/10.205 [pdf via DigitalCommons].

© Ted C. MacRae 2016

Posted in Buprestidae, Coleoptera, Fabaceae, Scarabaeidae | Tagged , , , , , , , , | 2 Comments

2015 Texas Collecting Trip iReport—Fall Tiger Beetles

This is the fourth in a series of “Collecting Trip iReports”—so named because I’ve illustrated them exclusively with iPhone photographs. As I’ve mentioned in previous articles in this series (2013 Oklahoma2013 Great Basin, and 2014 Great Plains), I tend to favor my iPhone camera for general photography—i.e., habitats, landscapes, miscellaneous subjects, etc.—during collecting trips and save my full-sized dSLR camera only for those subjects that I want high-quality macro photographs of. iPhones are not only small, handy, and quick but also capable (within reason) of quite good photographs (see this post for tips on making the most of the iPhone camera’s capabilities). This keeps the amount of time that I need to spend taking photos at a minimum, thus allowing more time for the trip’s intended purpose—collecting! Those photos form the basis of this overall trip synopsis, while photos taken with the ‘real’ camera will be featured in future posts on individual subjects.

Last year during late September and early October I travelled to eastern and central Texas. This trip was all about fall tiger beetles, in particular certain subspecies of the Festive Tiger Beetle (Cicindela scutellaris) and Big Sand Tiger Beetle (Cicindela formosa) found in that area that I had not yet seen. I enjoy all collecting trips, but fall tiger beetle trips are among the most enjoyable of all—cooler temperature, a changing landscape, and charismatic subjects that are both fun and challenging to find and photograph. This trip was no different, with spectacular weather during the entire week and, for the most part, great success in finding the species/subspecies that I was after. At this point I’d like to acknowledge the help of several people—David Hermann (Ft. Worth, Texas), David Brzoska (Naples, Florida), and Steve Spomer (Lincoln, Nebraska), who generously provided information on species and localities. My success at finding these beetles was due in large part to the information they provided.


Day 1 – Cobb Hollow

My car

Little question about what I am doing out here.

After driving 700 miles from my home near St. Louis, I arrived at the first stop of trip—Cobb Hollow in north-central Texas. This small creek lined with deep, dry sand is close to Forestburg (Montegue County)—the type locality of Cicindela scutellaris flavoviridis, a beautiful, all-green subspecies with the elytra suffused golden-yellow.  The habitat looked very promising from the start, and it wasn’t long before I found the first tiger beetle of the trip—a gorgeous, red nominate Big Sand Tiger Beetle (Cicindela formosa formosa). Not long after that I found the first Cicindela scutellaris flavoviridis, and over the next few hours I would find a total of nine individuals. Despite the extensive habitat along the creek the beetles were quite localized, occurring primarily in two dry sand areas within a mile west of the bridge. This spot is actually near the northern limit of the subspecies’ distribution, and several of the individuals showed varying influence from nominate scutellaris with the elytra tending to be more red than yellow-green. There was a diversity of other tiger beetles here as well—C. formosa formosa was the only one that was common, but I did find also a few individuals each of Tetracha carolina, Cicindelidia punctulata, Cicindela splendida, and C. repanda. A very cool place.

Cobb Hollow from bridge

View of Cobb Hollow east from the bridge

Sand bar along creek

Dry sand deposits line the creek.

Robber fly with bumble bee prey

I watched this robber fly snag a bumble bee in mid-flight.

Ted MacRae at Cobb Hollow

Looking down onto the creek from the bridge.


Day 2 – Stalking the Limestone Tiger Beetle

Today was all about looking for the Limestone Tiger Beetle, Cicindelidia politula. I have collected this species previously at several sites in Erath and Somervell Counties, Texas (west of Ft. Worth) and featured photographs from that trip. However, since I would be passing through the area on my way south I decided to spend a day looking for it again and, hopefully, collecting a few more specimens. Cicindelidia politula is related to the much more common and widespread Punctured Tiger Beetle, C. punctulata, but is shiny blue-black with the elytral markings absent or limited to the apices and the abdomen red. I visited several localities—two new ones for me in Erath County and another I had visited previously in Somervell County, with habitats that ranged from rocky clay to white limestone exposures along roadsides and even limestone gravel.

I found a fair number of individuals at the first site (1.7 mi SW Bluff Dale, Jct US-377 & FM-1188), which had a finely ground limestone substrate. Most of the individuals were flushed from the base of clumps of bunch grass and captured when they landed in more exposed situations.

Limestone habitat for Cicindelidia politula

Cicindelidia politula habitat—1.7 mi SW of Bluff Dale.

The beetle had also been reported along the roadsides at the second location (0.4 mi E Jct FM-2481 on CR-539), but the only individual I saw here was on a very coarse crushed limestone 2-track leading off of the main road.

Limestone habitat for Cicindelidia politula

Cicindelidia politula habitat—0.4 mi E Jct FM-2481 on CR-539.

The species was most numerous at the third site in Somervell County (3.4 mi SE Jct US-67 on CR-2013). I collected ten individuals and saw probably that many more on white limestone exposures along the roadside and along a dirt road cut along the base of the hill to the NE side of the highway. Most of the beetles in the latter area were seen along the scraped dirt road (at left in 2nd photo below), although presumably the beetles also utilized the undisturbed, surrounding habitat.

Limestone habitat for Cicindelidia politula

Cicindelidia politula habitat on white, limestone exposures along the roadside.

Limestone habitat for Cicindelidia politula

Cicindelidia politula habitat on white limestone hillside and scraped dirt road.

Catching the beetles at this last locality was challenging—the adults are fast and flighty, and the rough, rocky habitat made it difficult to clamp the net over the beetle and pounce on top of the rim before they were able to find a gap and escape. With practice I found my catch efficiency increased a little bit if I slowly approached the beetle and then made an assertive swing with the net right when the beetle began to fly—the trick is learning how to tell when they are ready to fly (and “assertive” is the key word!). Tiger Beetle Stalker; however, does not quit!

Tiger beetle stalker!

Tiger Beetle Stalker!


Day 3 (Part 1) – Pedernales Fall State Park

This was another locality where Cicindela scutellaris flavoviridis had been recorded. I came here to find this subspecies even though I had seen it two days previously at Cobb Hollow, because that latter population showed some slight intergradation of characters from nominate C. scutellaris and I wanted to get field photographs of a “pure” population. I was pretty excited when I saw extensive dry sand habitat lining the upper bank area along the Perdenales River; however, I found no tiger beetles of any kind after extensive searching through that habitat. I did note the area seemed dry and reasoned that perhaps timely rains had not yet triggered emergence of C. scutellaris, C. formosa, and other sand-loving fall tiger beetles. I did find a small area of wet sand right along the water’s edge where three species of Cicindelidia could be seen: C. ocellata rectilatera, C. trifasciata ascendens, and C. punctulata. I’ve photographed all of these species before, so I didn’t try to spend any time doing so here. However, combined with the species seen the previous two days, this made a total of ten species seen on the trip so far. Although I didn’t find the beetle I was looking for, I marveled at the beauty of the area, especially the Pedernales River with its hard, conglomerate bedrock and mini shut-ins and spent quite a bit of time here taking photographs.

Perdenales River

The Perdenales River is the centerpiece of the state park.

Schistocerca americana or nitens

Schistocerca americana or S. nitens (ID courtesy of Matt Brust).

Perdenales River

Shut-ins are extensive along the Perdenales River.

Poecilognathus sp.

Bee flies (family Bombyliidae), prob. Poecilognathus sp. (ID courtesy Rob Velten).


Day 3 (Part 2) – Lick Creek Park

Another of the Festive Tiger Beetle subspecies that I wanted to look for was Cicindela scutellaris rugata. I had several localities from which this solid blue-green subspecies has been recorded, and this site was the nearest of those that I planned to visit. The drive from Pedernales State Park was longer than I anticipated, so I didn’t get to this spot until close to 6 p.m. At first I worried that I wouldn’t have enough time to even find suitable habitat, but that was no problem as I quickly found the Post Oak Trail and its perfect open, post oak woodland with deep sand substrate. By all accounts the beetles should have been all over the trail but they weren’t. As with the previous site, the area was quite dry as evidenced by the wilted plants along the trail side, and I also note that the previous record from here was on Oct. 23rd—more than three weeks later. Despite the fact that I didn’t find any tiger beetles, I did see a young timber rattle snake (Crotalus horridus) crossing the trail late in the hike—I took a quick shot with the iPhone (see below) and then broke out the big camera and was able fire off a few shots before it left the trail and headed for cover. (Several people walking the trail came upon us, and they were all—happily—more than willing to oblige my requests to stay away until I was finished.)

Sand woodlant habitat for Cicindela scutellaris rugosa

Post oak woodland with dry sand substrate seems to be perfect for Cicindela scutellaris rugata.

Wilted American beautyberry (Callicarpa americana)

Wilted American beautyberry (Callicarpa americana).

Timber rattlesnake (Crotolus horridus)

A youngish (prob. ~32″ in length) timber rattlesnake (Crotolus horridus) was a treat to see.


Day 4 – East Texas cemeteries

Cemeteries are often great places to look for tiger beetles because they tend to be located on parcels of land with low agricultural value that were donated by landowners to local churches. Older cemeteries especially tend not to be highly maintained and, thus, offer excellent habitat for tiger beetles. My goals for this day were Cicindela scutellaris rugata and the gorgeous Cicindela formosa pigmentosignata. I had records of both from a couple of cemeteries in eastern Texas (Sand Flat Pioneer Cemetery in Henderson and Morris Chapel Cemetery in Van Zandt Counties) and found good numbers of both along sandy 2-tracks and sparsely to moderately vegetated sand exposures in and around the cemetery grounds. I don’t have any iPhone photographs to share of either of these species, but I did spent a lot of time with the big camera and got a number of photos of each that I am quite pleased with—I’ll share those in future posts. The cemeteries themselves were haunting and poignant, with some headstones dating back to the late 1800s.

Sandy 2-track habitat for Cicindela scutellaris rugata & C. formosa pigmentosignata

Sandy 2-track habitat for Cicindela scutellaris rugata & C. formosa pigmentosignata at Sand Flat Pioneer Cemetery, Henderson County, Texas.

 

Ant mound

Pogonomyrmex sp. poss. barbatus tend their nest entrance (ID courtesy of Ben Coulter).

Sand Flat Pioneer Cemetery

Oldest section of Sand Flat Pioneer Cemetery.

Died Nov 10, 1874

Fallen, but not forgotten—yet (died Nov 10, 1874).

Oldest headstones (late 1800s)

Oldest headstones (late 1800s) at rest under the shade of huge, red-cedar trees.

Oldest person (106 yrs old)

The oldest person died at 106 years of age (born in 1804).

At Morris Chapel Cemetery I found C. formosa pigmentosignata and C. scutellaris rugata on sparsely vegetated deep dry sand 2-track north of the cemetery. I did also manage to get field photos of the former before it got too hot and they became too active. There were also a few of the latter in the open sandy ground just outside the northwestern edge of the cemetery. As with Sand Flat Pioneer Cemetery, I spent a bit of time in the cemetery proper to look at the headstones—the oldest headstone also being the most poignant; a one and a half-year old boy who died in 1881.

Sandy 2-track habitat for Cicindela scutellaris rugata & C. formosa pigmentosignata

Sandy 2-track habitat near Morris Chapel Cemetery.

Morris Chapel Cemetery

A large, spreading post oak shades pioneers at rest.

Died 1881 (age 1½ yrs)

A poignant headstone (died 1881 at 1½ years of age).

After finishing up at Morris Chapel Cemetery I returned to Sand Flat Cemetery to see if I could get more field photographs before the beetles bedded down for the night. The sun was still up when I arrived a little before 6 p.m., but the shadows were long and no beetles were seen. Not one to waste an opportunity, I broke out the big camera anyway and started photographing a large species of bee fly (family Bombyliidae) that was perching on the ground and on the tips of plains snakecotton (Froelichia floridana).

Undet. bee fly

Bee fly (family Bombyliidae), poss. Poecilanthrax lucifer? (ID courtesy Alex Harman).


Day 5 (Part 1) – Cowtown Bowman Archery Club

With both specimens and good field photos of Cicindela scutellaris rugata and C. formosa pigmentosignata in hand, I returned my attention to C. scutellaris flavoviridis. Again, I did already have specimens in hand from Cobb Hollow, but most of them showed some degree of intergradation with nominate C. scutellaris and I was hoping to see some “pure” individuals. Failing to find it at the more southerly locations (Pedernales State Park and Lick Creek Park), I had one more location in Tarrant County where the subspecies had been recorded—a sand borrow pit near the entrance of Cowtown Bowman Archery Club. Once again I searched the area thoroughly for a couple of hours during mid-morning but did not see the subspecies or any other tiger beetles. Conditions were overcast and cool (72°F), but I do not think this explains the absence of adults. Rather, I think I was on the early side of the season and they just hadn’t started emerging at this site.

While I was at the site I found several tiger beetle larval burrows in a moderately vegetated area near the deeper sand deposits that were occupied by Tetracha carolina, so I used the “stab” or “ambush” method to collect several 3rd instars for an attempt at rearing. For those of you who are not familiar with this technique, a knife is set at a 45° angle with the tip in the soil about 1″ from the edge of the burrow. Then you wait, sometimes for quite a while, until the larva reappears at the top of the burrow and STAB the knife assertively into the soil to block the larva from retreating. The larvae are extremely wary with excellent vision and will usually drop back down immediately when they see you, so you have to be ready and act quickly. Once the retreat is blocked, a simple twist of the knife to expose the larva is all that is needed. I prepared larval habitats by placing native soil with as intact a top layer as possible in plastic critter carriers, made a starter hole for each larva with a pencil, dropped each larva into one of the holes, and then pushed the soil to seal the burrow entrance. This prevents the larvae from crawling right back out of the starter burrow, which can result in them encountering and fighting each other. The larvae will eventually reopen the burrow entrance, but after being sealed inside for a while they usually accept the burrow and further modify it to suit their needs.

 

Sandy grassland habitat for Tetracha prob. carolina

Sandy grassland habitat for Tetracha carolina.

Larval burrows (lower left) can be recognized by their clean, almost perfectly round, beveled edge. The presence of fresh soil diggings cast to one side (upper right) indicates the burrow is occupied by an active larva.

Tetracha prob. carolina larval burrow

Tetracha carolina larval burrow with cast soil diggings.

Using the “stab” or “ambush” method to collect larvae. One must have patience to successfully use this method.

"Stab 'n; grab" method to collect tiger beetle larvae (Tetracha prob. carolina)

Using the “stab” or “ambush” method to collect tiger beetle larvae.


Day 5 (Part 2) – Cobb Hollow (epilogue)

Although I had found Cicindela scutellaris flavoviridis at this site on the first day of the trip, I had not taken any field photographs in hopes of finding a more “pure” population at one of the more southerly locations. That did not happen, so I returned to Cobb Hollow on this last day in the field to get field photographs from the population there. Temperatures were a bit cooler (mid-70s) and cloud cover was variable, actually sprinkling when I arrived mid-afternoon but eventually clearing. This seemed to have no detrimental effect on adult presence, and it may have actually helped as I was able to photograph the very first individual that I found to my heart’s content. I collected that individual and the next three that I saw by hand and found two more over the next hour—all on the same deep, dry sand bars west of the bridge where I had seen them previously. Curiously, Cicindela formosa was strangely absent from these same areas where they had been so numerous a few days earlier.

Habitat for Cicindela formosa formosa and C. scutellaris flavoviridis

Deep, dry sand deposit where most of C. scutellaris flavoviridis were seen.

On the east side of the bridge I collected two more Tetracha carolina in the same moderately vegetated sandy clay spot as last time, then went on to the furthest dry sand bar where I found and photographed (but did not collect) a single C. formosa (only one shot before it took off). I also found a female green lynx spider (Peucetia viridans) sitting on her egg mass and got some nice macro photos as well as this iPhone shot (talk about a face only a mother could love!).

???????????????????????????????????????????????????????????????????

Female green lynx spider (Peucetia viridans) atop her egg mass.


I hope you’ve enjoyed this collecting trip iReport. Stay tuned for true macro photographs of the tiger beetles and other insects/arthropods that I photographed on this trip in more subject-specific posts. You are also welcome to leave feedback in the comments below.

Ted MacRae w/ field collecting equipment & camera

© Ted C. MacRae 2016

Posted in Acrididae, Arachnida, Araneae, Asilidae, Bombyliidae, Cicindelidae, Coleoptera, Diptera, Formicidae, Hymenoptera, Orthoptera, Reptilia, Vertebrata | Tagged , | 9 Comments

Super duper June bugs

Last June, after spending the day collecting insects at Sand Hills State Park in south-central Kansas with Mary Liz Jameson, Jeff Huether and I setup our blacklights at the edge of the dunes. We were hoping to attract males of the genus Prionus, following a hunch that maybe the dunes—a popular historical collecting site—would prove to be the habitat for the enigmatic Prionus simplex (known only from the type specimen labeled simply “Ks.”). We knew it was a long shot, made even longer by a bright moon and the unseasonably cool temperatures that settled over the dunes as the sun dipped below the horizon, and in the end no Prionus would be seen. We did see, however, some other interesting insects, one of the more interesting being males of Hammond’s lined June beetle—Polyphylla hammondi. Almost immediately after sunset a number of these large, chunky-bodied beetles resembling super-sized versions of their far more diverse and commonly encountered relatives in the genus Phyllophaga (May beetles) began arriving at the lights—each one noisily announcing its visit by its loud, buzzing, flight and bumbling thud onto the ground nearby.

Polyphylla hammondi

Polyphylla hammondi | Sand Dunes State Park, Kansas

I’ve encountered beetles in the genus Polyphylla only occasionally over the  years, almost always at night as a result of their attraction to lights. The genus is most diverse in the southwestern U.S., and many species are found only in specific sand dune habitats (Young 1988, LaRue 1998). Their large size, relatively more restricted distributions, and less common occurrence make them interesting enough, but what made this encounter particularly interesting for me was the way the beetles—all males—held their fan-like antennae splayed out. Male Polyphylla have greatly enlarged antennae that they use to detect sex pheromones emitted by the female (Lilly and Shorthouse 1971). Many female Polyphylla are flightless, especially those restricted to sand habitats, and are rarely collected, and for some species they still remain unknown. In fact, the best way to find females is to listen for the sound of the males hitting the ground or vegetation once they have located a female (Skelley 2009).

Polyphylla hammondi

Male with antennae splayed to detect female pheromone.

It was clear to me that these males were actively searching for females. The greatly elongated antennomeres provide lots of surface area for sensory pores to detect female pheromones at low concentrations. I’d not seen this before and didn’t know how long it would last—many beetles have narrow windows of activity for mating that can be affected or restricted further by environmental cues such as temperature. I figured I’d better get some photographs on the spot while I could, and this was a smart decision as it wasn’t too long after I took these photos that the males stopped coming to the lights and those that were already there became inactive and no longer held their antennae so impressively splayed.

Polyphylla hammondi

Males cease activity after sunset.

In a recent paper describing a new western species of the genus, La Rue (1998) provided detailed notes on behavior that probably pertain to other sand dune inhabiting species as well. Males were observed to begin flying in late afternoon, making rapid, irregular flights several meters above the sand surface. However, as dusk approached, their flights became less erratic and more purposeful as they flew rapidly upwind and then returned in a slow zig-zag flight (indicative of osmoclinotaxic orientation). Mating occurred after they located a female sitting on the sand and alighted within a few centimeters of her. Several males were attracted to each female, further supporting the use of pheromones by the female to attract males. Males were also attracted abundantly to lights after dusk and ceased activity shortly to several hours after sunset, presumably because females cease releasing pheromone to attract them and burrow back into the sand.

REFERENCES:

LaRue, D. A. 1998. Notes on Polyphylla Harris with a description of a new species (Coleoptera: Scarabaeidae: Melolonthinae). Insecta Mundi 12(1–2):23–37 [pdf].

Lilly, C. E. & J. D. Shorthouse. 1971. Responses of males of the 10-lined June beetle, Polyphylla decemlineata (Coleoptera: Scarabaeidae), to female sex pheromone. The Canadian Entomologist 103:1757–1761 [abstract].

Skelley, P. E. 2009. A new species of Polyphylla Harris from peninsular Florida (Coleoptera: Scarabaeidae: Melolonthinae) with a key to species of the pubescens species group. Insecta Mundi 0085:1–14 [pdf].

Young, R. M. 1988. A monograph of the genus Polyphylla Harris in America north of Mexico (Coleoptera: Scarabaeidae: Melolonthinae). Bulletin of the University of Nebraska State Museum 11(2):vi+115 pp. [BioQuip preview].

© Ted C. MacRae 2016

Posted in Coleoptera, Scarabaeidae | Tagged , , , , , , , | 9 Comments

North America’s most recognizable longhorned beetle

One of the more impressive insects that we found during our visit to Sand Hills State Park in south-central Kansas last June was Plectrodera scalator, the cottonwood borer. Large and robust (in fact, the only larger species in the family are the prionid root borers and their kin), their striking checkered pattern of white pubescence on a glossy black body makes them perhaps the most recognizable of all North American longhorned beetles (Linsley & Chemsak 1984). The very robust body of this individual, along with the relatively shorter antennae (only about as long as the body) identify it as a female—males are generally smaller and less robust with the body slightly tapering and the antennae distinctly longer than the body.

Plectrodera scalator

Plectrodera scalator (Fabricius, 1792) | Sand Hills State Park, Kansas

The white coloration on the body of these beetles is not a cuticular pigment (which is rather rare in beetles and is most often associated with species found in white sand habitats, e.g., certain tiger beetles), but instead a result of dense mats of microscopic white setae. The patterns formed by these mats are apparently as unique to each individual as fingerprints are to humans (Yanega 1996), making these beetles at once immediately recognizable as a species yet distinctive as individuals.

Plectrodera scalator

Adults of this species are found most often on cottonwood.

These are said to be common beetles in their range across the eastern two-thirds of the country, especially so in the Great Plains where their favored host, cottonwood (Populus deltoides), is especially abundant. Despite this, I have encountered this species only a handful of times in more than 3o years of searching. I know they’re out there, even in my home state of Missouri where I recorded 154 specimens collected in the state and deposited in various collections (MacRae 1994). It was not until around 2000 that I even saw my first ones (on a cottonwood tree in a homeowner’s yard just across the Mississippi River in Illinois), and in fact this one was actually found by Mary Liz Jameson, who had accompanied us to the field that day. It makes me wonder if their coloration, so strikingly conspicuous when isolated against a clean, blue sky background, might actually afford some type of cryptic protection against the normal backdrop of foliage and branches on which they are normally found—a phenomenon that I call “conspicuous crypsis” and which I have noted for other longhorned beetles (e.g., Acanthocinus nodosus). Perhaps, with this species at least, I have not yet set my search image to notice them.

Plectrodera scalator

Large, robust size and a distinctive checkered pattern of black and white makes these beetles among the most recognizable longhorned beetles in North America.

REFERENCES:

Linsley, E. G. and J. A. Chemsak. 1984. The Cerambycidae of North America, Part VII, No. 1: Taxonomy and classification of the subfamily Lamiinae, tribes Parmenini through Acanthoderini. University of California Publications in Entomology 102:xi + 1–258. [preview]

MacRae, T. C. 1994. Annotated checklist of the longhorned beetles (Coleoptera: Cerambycidae and Disteniidae) known to occur in Missouri. Insecta Mundi 7(4) (1993):223–252. [pdf]

Yanega, D. 1996. Field Guide to Northeastern Longhorned Beetles (Coleoptera: Cerambycidae). Illinois Natural History Survey Manual 6, x + 174 pp. [preview]

Posted in Cerambycidae, Coleoptera | Tagged , , , , , , , | 18 Comments