Seminar on Oklahoma’s Glass Mountains

Earlier this week I gave a seminar to the Entomology Group of the Webster Groves Nature Study Society. Founded in 1920 and known locally as “WGNSS”, the organization seeks “to stimulate interest in nature study on the part of adults and children, to cooperate with other organizations in nature study, and to encourage amateur research in the natural science.” I’ve been an active member in the society’s Entomology Group since the early 1980s, and for almost five years now I have also served as editor for the society’s newsletter, Nature Notes (see this archive of recent issues). Occasionally they invite me to talk—sometimes to just the Entomology Group and other times to the Society as a whole—about my entomological exploits. This time I chose to focus on my several visits to the Glass Mountains in northwestern Oklahoma over the past few years, which readers of this blog may remember has been the source of an inordinate number of new state records and other significant finds for the beetles I study. The presentation provided an overview of the insects I’ve encountered during these visits, and for those who might be interested a PDF version of the presentation is posted here. 

Natural History of Oklahoma’s Glass Mountains…

Copyright © Ted C. MacRae 2014

What was that insect?

Yesterday I posted an identification challenge of a different sort. The main subject in the photo was a jewel beetle (family Buprestidae), but there was also another insect in the photo—a small parasitic wasp sitting on the branch below the beetle. Some of you saw it—Charley Eiseman was the first and correctly guessed it was a member of the family Encyrtidae, earning 5 pts, and Wikispecies editor gets 5 pts for further identifying it as a member of the genus Metaphycus. Honestly, I took several shots of the beetle and never saw the wasp until I examined the photograph during processing. I’m not certain, but I think the small object next to the wasp could be a scale insect (family Coccidae), which are known hosts of Metaphycus spp.

Of course, there is still the jewel beetle, and it wouldn’t be fair for me to award points for the wasp but not the beetle. Heath gets 5 pts for first identifying the beetle in the genus Agrilus; however, nobody was able to identify the species as A. granulatus—commonly associated with cottonwood and poplar (Populus spp.) across North America. Since Charley was the only person to mention both the beetle and the wasp, I’m going to give him a tie-breaking bonus point and declare him the challenge winner.

Populations of A. granulatus have been assigned to several subspecies—the beetle shown here (photographed June 2013 at Beaver Dunes, Oklahoma) represents the nominate form—restricted to the U.S. east of the Rocky Mountains, where it breeds in native eastern cottonwoods (P. deltoides) and introduced Lombardy poplars (P. nigra var. ‘Italica’). Agrilus granulatus is often confused in collections with A. quadriguttatus, but that species is associated with willow (Salix spp.) and can be further distinguished by the less dense pubescence of the lower face not obscuring the surface; the pronotum with the lateral margins evenly rounded and not strongly sinuate at the base, the median channel less distinct, and the lateral depressions scarcely pubescent; and the elytra more gradually narrowed posteriorly with the tips more acutely rounded and more coarsely serrulate and the pubescent spots less distinct (Fisher 1928).

Here are a few more photographs of the jewel beetle (without the wasp):

Agrilus granulatus granulatus on Populus deltoides | Beaver Dunes, Oklahoma

Agrilus granulatus granulatus on Populus deltoides | Beaver Dunes, Oklahoma

Agrilus granulatus granulatus on Populus deltoides | Beaver Dunes, Oklahoma

Agrilus granulatus granulatus on Populus deltoides | Beaver Dunes, Oklahoma

Agrilus granulatus granulatus on Populus deltoides | Beaver Dunes, Oklahoma

Agrilus granulatus granulatus on Populus deltoides | Beaver Dunes, Oklahoma

REFERENCE:

Fisher, W. S.  1928. A revision of the North American species of buprestid beetles belonging to the genus Agrilus.  U. S. National Museum 145, 347 pp.

Copyright © Ted C. MacRae 2014

Pop! goes the beetle

Alaus oculatus (eyed elater) | Beaver Dunes State Park, Oklahoma

Alaus oculatus (eyed elater) | Beaver Dunes State Park, Oklahoma

Last June while collecting beetles from cottonwood trees at Beaver Dunes State Park, Oklahoma, I came across one of my favorite beetles—Alaus oculatus, or eyed elater (family Elateridae, or click beetles). Large by click beetle standards, the most striking feature of eyed elaters is, of course, their false eye spots, which are not eyes at all but patches of pubescence—black surrounded by a narrow ring of white—intended to look like eyes and located prominently on the prothorax rather than the head. A handful of related species are also found in various parts of the U.S., all of which exhibit variations on this same eye spot theme. Undoubtedly these spots serve to frighten would-be predators, much like the false eye spots on the thorax of many lepidopteran caterpillars. The true eyes, of course, are much smaller and are located on the head in front of the “false eyes.” In contrast to the prominently visible eye spots, pubescence on the rest of the body seems to function in cryptic coloration. The mottled patterning blends in with the bark of trees where these beetles usually hang out for effective concealment.

Look into my eye(spot)s!

Look into my eye(spot)s!

If either of those first two lines of defense don’t work, the beetles exhibit “thanatosis” by lying still with legs and antennae appressed to the body to fool the would-be predator into thinking that they are already dead.

A ventral look at the clicking mechanism between the pro- and mesosterna.

Adults exhibit “thanatosis” (play dead)  when disturbed.

Their most remarkable defensive behavior, however, is their ability to snap or “click” their bodies with enough force to free themselves from the grasp of a novice predator (or careless entomologist). The click is produced by a large prosternal spine and mesosternal notch on the beetle’s underside. To click, the beetle arches back its head and pronotum to retract the spine from the notch cavity, the tip of which is then pressed against the edge of the notch. Muscles within the thorax contract, storing elastic energy, and as the flexible hinge between the pro- and mesothoraces moves, the spine slides until its tip passes over the edge of the notch, releasing the elastic energy stored in the thoracic musculature and snapping the spine back into the notch cavity with enough force to produce an audible click.

A large spine on the prosternum fits into a groove on the mesosternum.

A large spine on the prosternum fits into a groove on the mesosternum.

This clicking ability also comes in handy if the beetle frees itself from the grasp of a predator and lands on its back. While the beetle’s legs are too short to right itself, its click is capable of launching the beetle high into the air. By tumbling while in the air, the beetle has a 50% chance of landing on its feet (thus, several attempts may be required). When jumping from a hard surface, the beetle is actually capable of launching itself to a height that is several times its body length and can tumble several times while in the air. This raises an interesting question, since theoretically an elevation of only one body length and half of a body revolution are all that is needed for an upside-down beetle to right itself. The power of the click, thus, grossly exceeds the minimal requirement for righting, yet the beetles seem incapable of moderating the force of the click. Furthermore, the 50% probability of landing suggests that they are also incapable of controlling the orientation of their body during the jump and landing. Did the clicking mechanism initially evolve to combat the grasp of predators and was then co-opted for use in jumping, or was the ability to jump the selective pressure that drove its evolution?

Locked and loaded—the mechanism is primed for the click.

Locked and loaded—the mechanism is primed for the click.

Ribak & Weihs (2011) used biomechanical analyses with Lanelater judaicus to support the idea that the click evolved primarily as a mechanism for vertical jumping. They reason that the excessive vertical distance of the jumps ensures sufficient height when jumping from soft substrates such as foliage or loose soil. A followup study evaluating the effect of natural substrates (Ribak et al. 2012) found that jump height was dramatically reduced (by ~75%) when the beetles jumped from leaves that covered approximately half of the study site and that the reduction in jump height was directly correlated with the amount of work absorbed by the substrate. This provides further evidence that the beetles do not moderate their jumping force and instead simply aim to jump “as high as possible” and rely on random chance for landing back on their feet.

After clicking, the spine returns to its resting position out of the groove.

After clicking, the spine returns to its resting position within the groove.

REFERENCE:

Ribak, G., S. Reingold & D. Weihs. 2012. The effect of natural substrates on jump height in click-beetles. Functional Ecology 26(2):493–499 [abstract].

Ribak, G. & D. Weihs. 2011. Jumping without using legs: The jump of the click-beetles (Elateridae) is morphologically constrained. PLoS ONE 6(6):e20871. doi:10.1371/journal.pone.0020871 [full text].

Copyright © Ted C. MacRae 2014

Hairy milkweed beetle

Across the Great Plains of North America, sand dune fields dot the landscape along rivers flowing east out of the Rocky Mountains. Formed by repeated periods of drought and the action of prevailing south/southwest winds on alluvium exposed by uplifting over the past several million years, many of these dunes boast unique assemblages of plants and animals adapted to their harsh, xeric conditions. Some are no longer active, while others remain active to this day. Among the latter is Beaver Dunes in the panhandle of northwestern Oklahoma.

Beaver Dunes, Oklahoma

Beaver Dunes State Park, Beaver Co., Oklahoma

As I explored the more vegetated areas around the perimeter of the dunes, I spotted the characteristically hairy, fleshy, opposite leaves of Ascelpias arenaria. Known also as “sand milkweed,” this plant is associated with sand dunes and other dry sandy soil sites throughout the central and southern Great Plains. I always give milkweeds a second look whenever I encounter them due to the association with them by longhorned beetles in the genus Tetraopes. It wasn’t long before I spotted the black antennae and red head of one of these beetles peering over one of the upper leaves from the other side.

Tetraopes pilosus on Asclepias arenaria

Tetraopes pilosus on Asclepias arenaria | Beaver Dunes State Park, Oklahoma

This was no ordinary Tetraopes, however. Its large size, dense covering of white pubescence, and association with sand milkweed told me immediately that this must be T. pilosus (the specific epithet meaning “hairy”). Like its host, this particular milkweed beetle is restricted to Quaternary sandhills in the central and southern Great Plains (Chemsak 1963), and also like its host the dense clothing of white pubescence is presumably an adaptation to prevent moisture loss and overheating in their xeric dune habitats (Farrell & Mitter 1998).

Tetraopes pilosus

Species of Tetraopes have the eyes completely divided by the antennal insertions—thus, “four eyes.”

Tetraopes is a highly specialized lineage distributed from Guatemala to Canada that feed as both larvae and adults exclusively on milkweed (Chemsak 1963). Larval feeding occurs in and around the roots of living plants, a habit exhibited by only a few other genera of Cerambycidae but unique in the subfamily Lamiinae (Linsley 1961). Milkweed plants are protected from most vertebrate and invertebrate herbivores by paralytic toxins, commonly termed cardiac glycosides or cardenolides. However, a few insects, Tetraopes being the most common and diverse, have not only evolved cardenolide insensitivity but also the ability to sequester these toxins for their own defense. Virtually all insects that feed on milkweed and their relatives have evolved aposematic coloration to advertise their unpalatability, and the bright red and black color schemes exhibited by milkweed beetles are no exception.

Species of the genus Tetraopes are characterized by the completely divided eyes.

Adult beetles, like the leaves of their hosts, are clothed in white pubescence.

As  noted by Mittler & Farrel (1998), variation in coloration among the different species of Tetraopes may be correlated with host chemistry. Milkweed species vary in toxicity, with more basal species expressing simpler cardenolides of lower toxicity and derived species possessing more complex and toxic analogs. Most species of Tetraopes are associated with a single species of milkweed, and it has been noted that adults of those affiliated with less toxic milkweeds on average are smaller, have less of their body surface brightly colored, and are quicker to take flight (Chemsak 1963, Farrell & Mitter 1998). Thus, there seems to be a direct correlation between the amount of protection afforded by their host plant and the degree to which the adults advertise their unpalatability and exhibit escape behaviors. Asclepias arenaria and related species are the most derived in the genus and contain the highest concentrations of cardenolides. In fact, they seem to be fed upon only by Tetraopes and monarchs while being generally free from other more oligophagous insect herbivores such as ctenuchine arctiid moths and chrysomelid beetles that feed on less derived species of milkweed (Farrell & Mitter 1998). Accordingly, T. pilosus is among the largest species in the genus and has the majority of its body surface red. Also, consistent with it being more highly protected than others in the genus, I noted virtually no attempted escape behavior as I photographed this lone adult.

Asclepias arenaria

Asclepias arenaria (sand milkweed) growing at the base of a dune.

In addition to metabolic insensitivity to cardenolides, adult Tetraopes also exhibit behavioral adaptations to avoid milkweed defenses (Doussard & Eisner 1987). The milky sap of milkweed is thick with latex that quickly dries to a sticky glue that can incapacitate the mouthparts of chewing insects that feed upon the sap-filled tissues. Adult Tetraopes, however, use their mandibles to cut through the leaf midrib about a quarter of the way back from the tip. This allows much of the sticky latex-filled sap to drain from the more distal tissues, on which the beetle then begins feeding at the tip. Leaves with chewed tips and cut midribs are telltale signs of feeding by adult Tetraopes.

REFERENCES:

Chemsak, J. A. 1963. Taxonomy and bionomics of the genus Tetraopes (Coleoptera: Cerambycidae). University of California Publications in Entomology 30(1):1–90, 9 plates.

Doussard, D. E. & T. Eisner. 1987. Vein-cutting behavior: insect counterploy to the latex defense of plants. Science 237:898–901 [abstract].

Farrell, B. D. & C. Mitter. 1998. The timing of insect/plant diversification: might Tetraopes (Coleoptera: Cerambycidae) and Asclepias (Asclepiadaceae) have co-evolved? Biological Journal of the Linnean Society 63: 553–577 [pdf].

Linsley, E.G. 1961. The Cerambycidae of North America. Part 1. Introduction. University of California Publications in Entomology 18:1–97, 35 plates.

Copyright © Ted C. MacRae 2013

Why did it take 30 years to collect these beetles?

Poecilonota cyanipes

Poecilonota cyanipes (eastern poplar jewel beetle) | Beaver Dunes State Park, Oklahoma

This is the best known of the American species of Poecilonota, and the one most commonly collected east of the Rocky Mountain.—Evans (1957)

I’ve been interested in insects since I was a kid, but I didn’t really become a dedicated coleopterist until after I’d finished graduate school and started working as a field entomologist with the Missouri Department of Agriculture. It was a perfect job for a young entomologist with a bent for collecting—being outside all day inspecting nursery stock and driving the back roads checking insect traps. It wasn’t long before I found myself focusing on wood-boring beetles, due initially to their horticultural importance but eventually to their astounding diversity and intrinsic beauty. So began my formal survey of the families Buprestidae and Cerambycidae in Missouri, and I spent the next eight years collecting them in all corners of the state and examining every insect collection, public and private, that I could find that might contain Missouri representatives of these families. In the end, I documented a cool 350 species and subspecies in the two families combined, more than a fifth of which represented new state records (MacRae 1991, 1994).

Poecilonota cyanipes

The specific epithet ‘cyanipes‘ refers to the blue feet

One species, however, that I had expected to find almost completely eluded me. This, despite the quote above by Evans (1957) in his revision of the genus Poecilonota in North America. Although it had been recorded from much of North America east of the Rocky Mountains in association with poplars (Populus spp.) and willows (Salix spp), I never actually encountered P. cyanipes in the field and found just two specimens labeled simply “Mo” in the insect collection at the University of Missouri in Columbia. This puzzled me, as I had beaten countless branches of cottonwood (Populus deltoides) and willow in search of this species and found many of the other known poplar/willow associates. I had even already collected two specimens of its much rarer congener, P. thureura, off of a redbud tree at the entrance to the Entomology Building on campus while still in graduate school!

Poecilonota cyanipes

This species can be recognized by its coppery color and elongate, distinctly reddish elytral apices,

As is often the case, good comes to those who wait, and I’ve finally gotten my chance during the past two seasons to encounter this species in numbers—last year as prey taken from nest sites of the buprestid-specialist crabronid wasp, Cerceris fumipennis, and this past June on cottonwood trees in northwestern Oklahoma at Beaver Dunes State Park. The individual in these photos was the first one I found—beaten from the lower branch of a small, living cottonwood exhibiting significant branch dieback, and over the course of the next two days I managed to beat close to three dozen specimens from the small, stunted cottonwoods that dotted the park. I suspect that the combination of good timing—buprestids of many types were common on a number of woody plant species in the area—and susceptible hosts with abundant branch dieback due to protracted drought conditions over the past few years was the reason I was able to find so many of the beetles. A perfect storm for wood-boring beetles, so to speak!

Poecilonota cyanipes

The non-angulate pronotal sides distinguish this species from another eastern species, P. ferrea.

As suggested above, larvae of this species are associated exclusively with dead or dying branches of Populus and Salix (both in the family Salicaceae), often in association with galls made previously by other species of wood-boring beetles, e.g., Saperda concolor in poplar (Knull 1920) and Agrilus criddlei in willow (Wellso et al. 1976). In fact, with one exception (P. viridicyanea on Chilopsis linearis) all members of the genus seem to be associated exclusively with plants in these two genera. However, in addition to these plants, Nelson et al. (2008), in their catalogue of the Buprestidae of the U.S. and Canada, also included black locust (Robinia pseudoacacia) in the family Fabaceae as a larval host for P. cyanea. I am convinced that this record represents at best a mere incidental adult association, and there are other examples of such in the catalogue (the final preparation of which was completed after the untimely death of the senior author). This is unfortunate, since erroneous records in such ‘standard’ references tend to be propagated in subsequent literature, which already seems to have happened in the case of black locust as a larval host for P. cyanipes (Paiero et al. 2012).

REFERENCES:

Knull, J. N. 1920. Notes on Buprestidae with description of a new species (Coleop.). Entomological News 31(1):4–12 [BioStor].

MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri. Insecta Mundi5(2):101–126 [pdf].

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].

Nelson, G. H., G. C. Walters, Jr., R. D. Haines, & C. L. Bellamy.  2008.  A Catalogue and Bibliography of the Buprestoidea of American North of Mexico.  Coleopterists Society Special Publication No. 4, The Coleopterists Society, North Potomac, Maryland, 274 pp. [description].

Paiero, S. M., M. D. Jackson, A. Jewiss-Gaines, T. Kimoto, B. D. Gill & S. A. Marshall. 2012. Field Guide to the Jewel Beetles (Coleoptera: Buprestidae) of Northeastern North America. 1st Edition. Canadian Food Inspection Agency, 411 pp. [pdf].

Wellso, S. G., G. V. Manley & J. A. Jackman. 1976. Keys and notes on the Buprestidae (Coleoptera) of Michigan. The Great Lakes Entomologist 9(1):1–22.

Copyright © Ted C. MacRae 2013

Party on a pin oak

In September 2012 while collecting in western Oklahoma (Weatherford) I came across this interesting scene. It had been exceedingly dry in the area, and because of this few insects were out and about in the small city park that I stopped by to check for the presence of tiger beetles. I had nearly completed my circuit of the park when I came upon a moderate-sized pin oak (Quercus palustris) tree and noticed something on the lower trunk:

Six insect species representing five families in four orders share a sap flow.

Six insect species representing five families in four orders share a sap flow on the trunk of a pin oak.

No less than six insect species representing four orders were seen all huddled together at a darkly stained sap flow. This could be the result of slime flux, a bacterial disease that usually affects deciduous hardwoods that are under stress and results in darkly stained weeps on the trunk that are known to be attractive to a variety of insects. At the center sat a green June beetle (Cotinis nitida) and three bumble flower beetles (Euphoria inda)—all in the family Scarabaeidae (subfamily Cetoniinae). Covering the scarab beetles were half a dozen Texas Tawny Emperor (Asterocampa clyton texana) butterflies (family Nymphalidae, or Brushfooted Butterflies), and milling around the perimeter was a velvet ant (Dasymutilla creusa, I believe) in the family Mutillidae, an apparent flesh fly (family Sarcophagidae), and a true ant (family Formicidae). I guess this would be the equivalent to a watering hole in Africa with a lion, a hyena, a baboon, three vervet monkeys and six zebras all crouched shoulder-to-shoulder at its edge.

Euphoria sepulchralis feeds on a sap flow higher up on the trunk.

Euphoria sepulchralis feeds on a sap flow higher up on the trunk.

Further up on the trunk, yet another species of scarab beetle, a dark flower scarab (Euphoria sepulchralis) was found feeding on a smaller sap ooze. Unlike the diverse aggregation of insects on the lower ooze, this guy had managed to keep the ooze all to himself.

Cotinus nitidus | Weatherford, Oklahoma

Cotinis nitida | Weatherford, Oklahoma

Green June beetles, especially, are known for their feeding on sap oozes. The beetles are actually attracted to the odors caused by fermentation of the sap rather than the sap itself. It has been reported that the presence of alcohol in fermenting sap can affect the behaviour of insects that feed upon it, causing them to act “stupid and lethargic.” I did not see any such behavior, but I did notice that the insects were not at all skittish and loath to leave the sap.

Copyright © Ted C. MacRae 2013

Q: How do you photograph cactus beetles?

A: Very carefully!

This past June I went out to one of my favorite spots in northwestern Oklahoma—Alabaster Caverns State Park in Woodward Co. The park, of course, is best known for its alabaster gypsum cavern—one of the largest such in the world—and the large population of bats that occupies it. Truth be told, in my several visits to the park during the past few years I have never been inside the cavern. The draw for me is—no surprise—it’s beetles. On my first visit in 2009 I found what is now known to be one of the largest extant populations of the rare Cylindera celeripes (swift tiger beetle), previously considered by some to be a potential candidate for listing on the federal endangered species list, and last year I found the northernmost locality of the interesting, fall-active jewel beetle Acmaeodera macra. This most recent visit was the earliest in the season yet, and as I walked the trails atop the mesa overlying the cavern I noticed numerous clumps of prickly pear cactus (Opuntia phaecantha) dotting the landscape.

Opuntia phaecantha | Alabaster State Park, Woodward Co., Oklahoma

Opuntia phaecantha | Alabaster Caverns State Park, Woodward Co., Oklahoma

Whenever I see prickly pear cactus anywhere west of Missouri I immediately think of cactus beetles—longhorned beetles in the genus Moneilema. A half-dozen species of these relatively large, bulky, clumsy, flightless, jet-black beetles live in the U.S., with another dozen or so extending the genus down into Mexico and Baja California, and all are associated exclusively with cactus, primarily species of the genus Opuntia. It wasn’t long before I found one, and deliberate searching among the cactus clumps produced a nice series of beetles representing what I later determined as M. armatum. The resemblance between Moneilema spp. and darkling beetles of the genus Eleodes is remarkable, not only in their appearance but also in their shared defensive habit of raising the abdomen when disturbed. The genus has been related taxonomically to the Old World genus Dorcadion, but Linsley & Chemsak (1984) regard the loss of wings and other morphological modifications to represent convergence resulting from the environmental constraints imposed by root-feeding, subterranean habits in arid environments and other situations where flightlessness is advantageous.

Moneilema armatum adult.

Moneilema armatum adult in situ on Opuntia phaecantha pad.

I have encountered Moneilema beetles a number of times out west, including this species in Texas where it is most common, but since I have only been photographing insects for the past few years this was my first  chance to capture cactus beetle images as well as specimens. The above shot, taken with my iPhone, was straightforward enough, but I wanted some real photographs of the beetle—i.e., true close-up photos taken with a dedicated macro lens. I quickly learned that this would be highly problematic—those cactus spines are long and stiff and vicious, and these beetles are no dummies! Clearly their ability to adapt to such a terrifyingly well-defended plant has had a lot to do with the evolution of their slow, clumsy, flightless, you-don’t-scare-me demeanor. Normally when I photograph insects I do a little pruning or rearranging of nearby vegetation to get a clear, unobstructed view of the subject, and sometimes this also involves “pushing” my way into the vegetation to get the most desirable angle on the subject for the sake of composition. Not so here! In my first attempt, all I could think to do was locate a beetle sitting in repose and try to position myself in some way so that the beetle was within the viewfinder and the cactus’ spines were not impaled within my arms! The photo below shows the only shot out of several that I even considered halfway acceptable, but clearly the spines obstructing the view of the beetle were not going to be to my liking.

First attempt - looking down into plant where beetle was first sitting.

First attempt – looking down into plant where beetle was first sitting.

What to do? The beetle was behaving fairly well (i.e., it was not bolting for cover upon my approach), so I pulled out a pair of long forceps (that I carry with me for just such cases) and used them to gently prod the beetle into a more exposed position. The beetle crawled up onto one of the unopened cactus flower buds and perched momentarily, and I thought I had my winner photograph. I crouched down again, was able to get a little bit closer to the beetle than before, and fired a few shots. Looking at them in the preview window, however, left me still dissatisfied—the beetle was no longer obstructed, but the background was still jumbled, messy and dark, making it difficult for the dark-colored beetle to stand out. I would need to think of something else.

Second attempt - looking down on beetle after coaxing it up.

Second attempt – looking down on beetle after coaxing it up.

I actually take a lot of my photos with the insects sitting on plant parts that have been detached from the plant. This allows me to hold the plant in front of whatever background I choose and micro-adjust the position of the insect in the viewfinder for the best composition. This is “easier” (a relative term) with a shorter lens (think MP-E 65-mm) because the lens-to-subject distance matches almost perfectly the distance between my wrist and my fingers, allowing me to rest the camera lens on my wrist while holding the plant part with my fingers to “fix” the lens-to-subject distance. These beetles, however, are much too big for the MP-E 65-mm, so I had to use my longer 100-mm macro lens. The longer lens-to-subject distance does not allow resting the lens on my wrist, so I must come up with other ways of bracing myself and the subject to minimize movement. Detaching the pad on which the beetle was resting (and if you’ve never tried to detach an Opuntia cactus pad from its parent plant while trying not to disturb a beetle sitting on it, I can tell you it is not an easy thing), I also discovered that the pad was quite heavy and that holding it with the same forceps that I had used to prod the beetle (because of its vicious spines) was yet another unanticipated difficulty. I decided the best way to deal with it would be to get down on one knee in front of the plant, rest my arm on my other knee with the cactus pad extending out in front of me, and photograph the beetle with the plant as close in the background as possible to achieve a lighted and colored background that would help the beetle stand out. Following are examples of those attempts.

Third attempt - holding detaching pad with forceps for better view.

Third attempt – holding detaching pad with forceps for better view.

Detached allows even better close-ups.

Detached allows even better close-ups.

Better for sure, especially the latter, closer one. Still, I wasn’t satisfied—the backgrounds still just had too much clutter that detracted from the beetle and complicated the lighting. I decided to go for broke—why not go for the blue sky background, the cleanest, most natural and aesthetically pleasing background possible! This actually was my first thought when I saw the beetles, but I could never find one on a high enough plant that was growing in a situation where I was able to crouch low enough to get the angle with the sky in the background. By this time my arm was quite weak from holding the heavy cactus pad and squeezing the forceps firmly, and as I contemplated how I could possibly hold the pad up towards the sky and take the shots without being able to rest the camera on my arm I had an idea. Why not rest my arm on the camera? Specifically on top of the flash master unit atop the camera. I adjusted the camera settings for blue sky background, positioned the cactus pad in the forceps so that the pad (and beetle) were hanging down from the forceps but still in an upright position, pointed the camera to the brightest part of the sky (a few degrees from the sun), and then held the cactus pad out in front of the camera with my arm resting on the flash master unit. It worked! My arm still got tired quickly and needed frequent breaks, and I had to do a number of takes to get the exposure settings and composition I was looking for, but the photo below represents my closest approach to what I envisioned when I first knelt down to photograph these beetles. A clear view of the beetle, on its host plant, with lots of nice value contrast between beetle, plant and background.

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

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

Once I had the technique figured out, I was able to get some really close-ups shots as well, still, however, with enough blue sky in the background to make it clean and pretty…

Zooming in with sky background gives a nice, clean close-up.

Zooming in with sky background gives a nice, clean close-up.

…as well as playing with some unusual compositions that one can afford to try only after they are confident they have gotten the required shots. I am particularly fond of the following photo, in which the beetle appears to be “peeking” from behind its well-defended hiding place on its host plant.

Having a little fun with the close-ups - he's peaking!

Having a little fun with the close-ups – he’s peaking!

If you have any experiences photographing these or other such “well-defended” insects (without resorting to the white box!) I would love to hear about them.

REFERENCE:

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 102:1–258 [preview].

Copyright © Ted C. MacRae 2013