Month: January 2013

Diffusion versus post-processing, or perhaps something even better?

/ Ted C. MacRae / 10 Comments

One of the comments on my post Diffuser comparisons for 100mm macro lens was by Stephen Barlow, one of the original “concave diffuser” advocates, who claimed that the “dead” appearance of Photo #4 was an artifact of post-processing and not really a problem with the diffusion method itself. Heeding this comment, I reprocessed Photo #4 to see if this was really all that was needed to give it a “livelier” look by rather aggressively bumping up the brightness and contrast by 30% each (to correct for underexposure), then reducing the saturation by 10% (to correct for the effect on color caused by increased brightness and contrast), adjusted levels to a set point of 240 to add some more “high end,” and reduced highlights and shadows just a bit (10% each). Following is the original and then the reprocessed version of Photo #4:

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Original post-processing

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Additional post-processing.

There is no question that this additional reprocessing has greatly improved the photo. However, after I did this I got to thinking—why not try combining the two diffusers that gave the best results? Recall that the diffusion method in Photo #5 (SoftBoxes on flexible arm extenders) easily “won the vote” over Photo #4 (open concave diffuser) by a 2:1 margin (35 to 17). This may have been at least partly a result of the less than flattering post-processing of the original version of #4, but still the overall lighting effect on Photo #5 caused by the diffusion method used was quite dramatic. The only downside of the #5 method was the persistence of hot spots (albeit muted) from the flash heads and a dark background with lots of shadowing caused by light drop off (since the flash heads were mounted on the lens rather than extenders). Double diffusers are nothing new, the idea being that the first diffuser spreads the light out more before it hits the second diffuser than does a bare flash head, allowing even further diffusion of the light the reaches the subject (and background) for truly even lighting. I reasoned that using SoftBoxes on flexible arm extenders plus the concave diffuser would not only accomplish double diffusion but also allow controlled placement of the flash heads close to the specimen to maximize apparent light size and minimize light drop off. To test this I re-shot the same beetle with the same camera settings, and here is the result:

Flash heads mounted on flexible arms, diffused by SoftBoxes + open concave diffuser

Flash heads mounted on flexible arms, diffused by SoftBoxes + open concave diffuser

My personal opinion is that this photo combines the best of both methods. While loss of light can be a problem with double diffusion, my use of extenders to place the flash heads close to the subject minimizes, or perhaps even completely negates this problem. Additionally, while subtle hot spots are still apparent, they are not nearly as apparent as in Photo #5 (SoftBox diffusers on extenders w/o concave diffuser—refresh your memory here) due to the additional diffusion, which also dramatically reduces shadowing as a result of better light throw. The hot spots are also more subtle than in #4 because of the larger apparent light size (a combination of closer flash head placement and the SoftBoxes), and is it just me or are the colors more vibrant and life-like in this photo compared to #4 (even reprocessed)? The flat colors were my biggest criticism of Photo #4, and even heavy-handed reprocessing, while helpful, didn’t completely bring it “back to life.” In contrast, the double-diffused photo required only typical post-processing to achieve a more than acceptable result—I have to believe that, all other things being equal, a photo that requires less post-processing is better than one that requires more.

Of course, using a setup like this in the studio is one thing—using it in the field is another. Both the extenders and the oversized concave diffuser are likely to make things a little clumsier in the field, and the two combined may be more clumsiness than I care to deal with. Nevertheless, the results from my test shots are certainly promising enough to give it an honest effort. Have I finally found a viable solution to diffusion in long-lens, full-flash macrophotography? We’ll find out this summer!

Copyright © Ted C. MacRae 2013

The Texas Prick

/ Ted C. MacRae / 47 Comments

Recently my friend Kent Fothergill launched a series of posts ranting about discussing the difficulties associated with common names. The inaugural post featured the insect I show here, Dectes texanus, a member of the family Cerambycidae (longhorned beetles) that has gained attention in recent years as an occasional pest of soybeans, especially in the upper Mississippi Delta (Tindall et al. 2010). As is usual, when an otherwise obscure little insect suddenly begins costing somebody money people feel compelled to give it a common name. Rather than the uninspired “soybean stem borer” or ironically Latin-ish “Dectes stem borer” monikers that seem to have taken hold for this species, Kent jokingly suggested that if people were serious about common names, this insect should actually be called the “Texas prick” as a direct translation of the scientific name.¹

¹ Actually, I couldn’t find any reference to the word “Dectes” as a Latin word or “prick” as its English translation. Rather, my copy of Brown (1956) lists dectes as a Greek word meaning “biter.” I think this must be what LeConte (1852) had in mind when he first coined the genus name, since he mentions among the characters that define the genus several features of the mandibles. If that is the case, then to be accurate the alternate common name for this beetle should be the “Texas biter.” However, that name causes nothing like the snicker that “Texas prick” elicits, and since common names are bound by no rules whatsoever, I choose levity over accuracy and stick with Kent’s proposed name.

Dectes texanus (dectes stem borer) | Washington Co., Mississippi

Dectes texanus | Washington Co., Mississippi

Being the pedantic, anal retentive, taxonomist-type that I am, it may surprise you to learn that I actually don’t have a problem with common names. To be honest, however, I will admit that this is a fairly recent change-of-mind for me—for many years I was a die-hard “scientific-names-only” type of guy. I not only thought common names were useless (for all the reasons listed by everybody who opposes them), but I even refused to learn them—my geek passive aggression, I guess. In the years since I started this blog, however, I’ve not only grown less oppositional in my stance, but have actually learned to embrace common names for what they are—comfortable names that don’t intimidate the taxonomically disinclined. Labels is all they are, and if one common name can refer to several species or several common names refer to one species, it’s not the end of the world. Common names aren’t meant to replace scientific names—how could they? Scientific names fulfill a special set of needs for a select group of people (i.e., to reflect phylogeny), and despite its flaws the Linnaean system of nomenclature that has been in use for the past several hundred years has served this purpose better than any other system devised. The reason for this is because genus and species names also provide a convenient and relatively easily memorizable system of labels that allow scientists to actually talk about organisms in a way that makes sense. This is an advantage that the Linnaean system has over any numerical phylogenetic system, no matter how much more precisely the latter can indicate phylogeny. For scientists, scientific names, in effect, serve a dual purpose. Non-taxonomists, however, don’t need dual purpose names—they just want easy-to-say and easy-to-remember labels, and if common names engage more people in a discussion about nature and its inhabitants then I’m all for it.

a.k.a. ''The Texas Prick''

Accepted common name: Dectes stem borer; BitB common name: ”Texas Prick”

This is not to say that I will ever give up scientific names. I love scientific names, and it is my goal in life to know as many of them as possible—even synonyms (I know, sick!). I also think that scientific names are not as scary as some people believe. Boa constrictor, for example (yes, that is both its common and scientific name), or gorilla (Gorilla gorilla)… or Dectes stem borer! To help bridge the gap, I have taken to mentioning, as a matter of practice, both the scientific name and—when one exists—the common name for the insects and other organisms featured on this blog. This applies not only at the species level, but families and other higher taxa also (e.g., “jewel beetles, family Buprestidae”). It is my way of talking science in a way that welcomes the interested lay person. Considering the increasingly anti-science din in our country by creationists, climate change denialists, knee-jerk GM critics, etc., I think the more we can get scientists and non-scientists comfortable talking to each other the better off we will be.

The insect featured in this post was found and photographed in a field of cultivated soybeans in northeastern Mississippi. It’s identification as Dectes texanus (other than its association with soybean) is based on the face being only slightly protruding and the relatively large lower lobe of the eye. There is one other species in the genus, D. sayi, also broadly distributed in the U.S. but distinguished from D. texanus by its distinctly more protruding face and small lower eye lobe (giving the impression of “tall cheeks”). This species, too, is known to bore in the stems of soybean but is much happier doing so in common ragweed (Ambrosia artemisiifolia) (Piper 1978). The species name—sayi—was given to honor the 19th century entomologist Thomas Say, regarded by many as the ‘Father of American entomology.’ This species also has been called “soybean stem borer” by some, which doesn’t do much to alleviate concerns about common names referring to multiple species. I am reluctant, however, for reasons of respect, to use the common name for D. sayi that results if one uses the same rationale used by Kent in coining his common name for D. texanus…

REFERENCES:

Brown, R. W. 1956. Composition of Scientific Words. Smithsonian Institution Press, Washington, D.C., 882 pp.

LeConte, J. L. 1852. An attempt to classify the longicorn Coleoptera of the part of America north of Mexico. Journal of the Academy of Natural Sciences Philadelphia (series 2) 2(1):99–112.

Piper, G. L. 1978. Biology and immature stages of Dectes sayi Dillon and Dillon (Coleoptera: Cerambycidae). The Coleopterists Bulletin 32(4):299–306.

Tindall K. V., S. Stewart, F. Musser, G. Lorenz, W. Bailey, J. House, R. Henry, D. Hastings, M. Wallace & K. Fothergill. 2010. Distribution of the long-horned beetle, Dectes texanus, in soybeans of Missouri, Western Tennessee, Mississippi, and Arkansas. Journal of Insect Science 10:178 available online: insectscience.org/10.178.

Copyright © Ted C. MacRae 2013

How to collect larvae of Amblycheila cylindriformis

/ Ted C. MacRae / 19 Comments
Amblycheila cylindriformis larval burrow | Major Co., Oklahoma

Amblycheila cylindriformis larval burrow | Major Co., Oklahoma

Step 1. Go to your favorite grassland habitat in the western half of the Great Plains anywhere from Texas north to South Dakota and look for barren soil amongst the vegetation. Clay banks near streams or in ravines and even vertical clay bluff faces are also good (although I have not myself observed the latter). “My” spot is in the Glass Mountains of northwestern Oklahoma, where talus slopes in mixed-grass prairie beneath flat-topped mesas and the ravines that cut through them provide just enough slope for this species’ liking.

Burrow diameter of ~8mm identifies this as a 3rd instar larva.

Burrow diameter of ~8mm identifies this as a 3rd instar larva.

Step 2. Look for large, almost perfectly round burrow entrances that go straight down from the surface. By large, I mean approximately 6–8 mm in diameter—as large a burrow as any tiger beetle in North America will make. Many other insects create burrows, but tiger beetle burrows are generally recognizable by their almost perfectly circular shape and clean, beveled edge. Look closely, and the burrow will be seen to actually be slightly D-shaped to match the shape of the tiger beetle larva’s head—the large, sickle-shaped, upward-facing jaws resting against the flat part of the D. In the case of this species, they tend to be found in clusters of several burrows in close proximity to each other. The burrow in these photos was found at the upper edge of a drainage ravine on the upper part of the talus slopes (see diagram in this post).

Dig around the burrow, carefully excavating along the grass stem, until the larva is reached.

Dig around the burrow, carefully excavating along the grass stem, until the larva is reached.

Step 3. Try this first—chew the end of a long, narrow grass stem (frayed and sticky will be easier for the larva to grab hold of) and stick it down the burrow until it hits bottom, tap lightly a few times to entice a bite, then yank (and I mean yank!) the stem out. With luck, the larva will come flying out of the burrow and land somewhere on the ground in front of you. (By the way, if you have never done this, you are missing one of the greatest treats that insect collecting has to offer. If you have done it, you owe it to yourself to show this to somebody else who has not ever seen it—their shocked reaction at the sight of the flying larva is beyond priceless!) Larvae are not always in the mood to bite, however, so if the so-called “fishing” technique does not work then you will have to dig. Stick the grass stem back down the burrow and begin excavating around the burrow, carefully prying away the soil adjacent to the burrow to prevent it from falling into and obscuring the burrow. Keep excavating as you follow the grass stem down until, at least, you reach the larva. In the photo above you can see in the lower right-center area the burrow with the grass stem protruding from it and the larva placed on a clump of soil in front of the shovel (for sense of scale). It seems I had an easy time of it with this larva, as literature sources report larval burrows extending down to depths of a meter or more.

Amblycheila cylindriformis 3rd instar larva.

Amblycheila cylindriformis 3rd instar larva.

Step 4. Behold the beast! There is nothing more that can be said—these larvae are ginormous! This particular larva measured a full 62 mm from the tips of its mandibles to the tip of its abdomen—that’s 2½ inches! No other tiger beetle larva in North America reaches this size, except perhaps the related A. hoversoni (South Texas Giant Tiger Beetle).

The distinctly smaller 2nd pair of eyes confirm this is not Tetracha or Cicindela (sensu lato)...

The distinctly smaller 2nd pair of eyes confirm this is not Tetracha or Cicindela (sensu lato)…

Step 5. If size alone isn’t enough, you can confirm that the larvae does indeed belong to the genus Amblycheila by looking at its eyes—their are two pairs, and the 1st pair (closest to the mandibles) are distinctly larger than the 2nd pair. This isn’t clearly visible in the photo above because I doused the larva with water to remove the mud and dirt that encrusted it upon removal from its burrow.

...and the well-separated hooks on the 5th abdominal segment confirm it is Amblycheila.

…and the distinctly separated hooks on the 5th abdominal segment confirm it is Amblycheila.

Step 6. Another way to distinguish larvae of the genus Amblycheila is by looking at the hooks on the hump of the 5th abdominal segment, best done with a hand lens (or, even better, with an MP-E65 lens!). All tiger beetle larvae have several pairs of large hooks that the larva uses to brace itself against the wall of its burrow when capturing prey to prevent the struggling prey from pulling the tiger beetle larva out of its burrow. Larvae in the genus Omus, restricted to the Pacific region of North America, have three pairs of hooks (referred to as the outer, middle, and inner hooks), while all other North American tiger beetle genera have two (having lost the outer pair). In Amblycheila and Tetracha the hooks are simple and thornlike, while larvae of all other North American genera have much longer middle hooks that are curved and sickle-shaped (e.g., Cylindera celeripes in this post). Amblycheila larvae can be distinguished from Tetracha larvae by the middle and inner hooks on each side being distinctly separated rather than touching at the base (e.g., Tetracha floridana in this post). There is also a cluster of short, stout hairs around the base of each hook in Amblycheila that is missing in Tetracha (e.g., Tetracha virginica in this post).

The numerous stout setae are also characteristic of the genus.

The numerous stout setae are also characteristic of the genus.

Step 7. Lastly, don’t forget to look at the hump in lateral profile—it is as alien a structure as any in the insect world. In the case of Amblycheila larvae, the bed of hairs posterior to the hooks is comprised of much shorter, stouter, and more densely placed hairs than larvae of Tetracha.

Copyright © Ted C. MacRae 2013

You know what bugs me about dung beetles?…

/ Ted C. MacRae / 12 Comments
...Their silly little shit-eating grins!

…Their silly little shit-eating grins!

Okay, I know this isn’t a true dung beetle, but this earth-boring scarab (family Geotrupidae) is close enough that I’ll take the opportunity to use one of my favorite dung beetle jokes.¹ This is one of several individuals that I saw on a late October hike along the North Fork Section of the Ozark Trail in extreme south-central Missouri (just a few miles north of the Arkansas border). I regard these beetles to represent the species Geotrupes splendidus based on the punctured elytral striae, sutural striae ending at the scutellum, bright green coloration, and obvious punctures in the lateral areas of the pronotum. Of the half dozen adults that I saw during the day, all were found singly on animal dung or on the ground nearby.  This was the most abundantly I’ve ever seen this species—up to that point I’d accumulated only a handful of specimens, always on mild days in late fall or early winter in association with animal dung on trails through high quality woodlands. The timing and circumstance is also true for Geotrupes blackburnii, the only other species in the genus that I have collected in Missouri—albeit much more commonly and abundantly than G. splendidus and easily distinguished from that species by its slightly smaller size, nearly impunctate pronotum and all black coloration.

¹ By the way, I don’t recall the provenance of that joke, other than I saw it as a one-frame cartoon, featuring two entomologists talking to each other, posted on a Department of Entomology door while I was in graduate school—way back in the early 1980s. If you know please tell me!

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Geotrupes splendidus miarophagus | Ozark Co., Missouri—yes, it’s sitting on shit!

An interesting contrast between this species and true dung beetles (scarabs in the subfamily Scarabaeinae and representing such genera as Copris, Phanaeus, Canthon, Onthophagus, etc.) is the fact that while this species can and does utilize dung for both larval development and adult feeding, it is not the preferred food. Rather, adults are more often found feeding on fungus, and leaf litter—tightly packed by the adult at the end of a burrow in the soil, is most often used for larval development (Howden 1055). This does not seem to be a universal feature of the genus, as the common Missouri species, G. blackburnii, does seem to prefer dung for larval development. This is not to say that either species is exclusive in its preference—both seem to be more flexible in food choice than the true dung beetles, but in reality the larval biology of a great many species in this and other genera of the family remain unknown.

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The opinion of scarab expert would be most helpful at this point. This species is broadly distributed across eastern North America, with eastern populations generally brighter green and western populations (e.g., here in Missouri) more often yellow-green with golden or reddish hints but ranging to dark purple. In fact, all but one of the Missouri specimens in my collection are dark purple, the other being green similar to the six beetles I saw on this date. Howden (1955) recognized the western forms as a separate subspecies, G. splendidus miarophagus (originally described as the species G. miarophagus by Thomas Say). These two subspecies are listed as valid in the recent checklist of Nearctic Scarabaeoidea (Smith 2003), and the specimens in my collection from Missouri are labeled as such by scarab expert Bill Warner. Despite this, most other sources I’ve checked—including BugGuide—list G. miarophagus as a synonym of G. splendidus. Color alone—especially when it is as variable as in this species—seems weak justification for subspecific distinction. Howden (1955) mentions a curious case of G. s. miarophagus utilizing fresh grass clippings for larval development; however, it is difficult to imagine this as anything more than just a very recent adaptation. If there are other reasons supporting subspecific distinction besides deference to Henry Howden, I’d be interested in knowing what they are.

REFERENCES:

Howden, H. F. 1955. Biology and taxonomy of North American beetles of the subfamily Geotrupinae with revisions of the genera Bolbocerosoma, Eucanthus, Geotrupes and Peltotrupes (Scarabaeidae). Proceedings of the United States National Museum 104:151–319.

Smith, A. B. T. 2003. Checklist of the Scarabaeoidea of the Nearctic Realm. Version 3. Electronically published, Lincoln, Nebraska. 74 pp.

Copyright © Ted C. MacRae 2013

These are a few of my favorite trees

/ Ted C. MacRae / 6 Comments

Adrian Thysse recently posted a video of a talk by Wayne Maddison titled “Jumping Spider Melodies,” given November 2012 at the Joint Annual Meeting of the Entomological Society of Canada and the Entomological Society of Alberta. It was a fascinating talk that revealed some interesting correlations between the phylogeny and geographical patterns of distribution of jumping spiders—those bright-eyed, bouncy, almost kitten-like darlings of the spider world. One quote from the talk, however, that stood out for me above all others went something like “Scientists have a rational motivation to seek truth and an emotional motivation to seek beauty.” I think this is true especially for biologists and natural historians—who among us that studies that natural world in adulthood didn’t start out with a love of the outdoors as a child? For me it was the woods that ignited my passion, and still today nothing rejuvenates my spirit like the overwhelming beauty and solitude of the forest.

Shortleaf pine (Pinus echinata) | Wayne Co., Missouri

Shortleaf pine (Pinus echinata) | Wayne Co., Missouri

Wintertime especially is when I enjoy my visits to the forest. Far from the cacophony of summer, my mind is free to explore the open canopy, to examine the fabric of the landscape and ponder its history—unhurried, without objective. During the summer, trees are host plants—I see them not for what they are, but for the beetles that might be on them. I identify them, sample them, assess them for where their guests might be. In winter though, without beating sheet in hand, without collecting vials in the pocket, I see trees as works of art—freed from their summer cloaks, living skeletons on a living landscape.

Honey locust (Gleditsia triacanthos) | Wayne Co., Missouri

Honey locust (Gleditsia triacanthos)

Different trees are my favorite at different times for different reasons. Blazing hot orange sugar maples (Acer saccharum) at peak fall color, stately white oaks (Quercus alba) with their ash-gray branches, broad-crowned post oaks (Quercus stellata) dotting a remnant savanna, or even gnarled, ancient red-cedars (Juniperus virginiana) clinging tenuously to life on the edge of a dolomite bluff. Most often for me, however, the beauty is in the bark. The deeply fissured, reddish plates of shortleaf pine (Pinus echninata), the terrifyingly thorned trunks of honey locust (Gleditsia triacanthos), the shaggy, peeling strips of shagbark hickory (Carya ovata). Even in their winter nakedness, the bark of these trees gives them year-round personality that is lacking in lesser-barked trees.

Shagbark hickory (Carya ovata) | Wayne Co., Missouri

Shagbark hickory (Carya ovata)

Honey locust (Gleditsia triacanthos) - thornless individual | Wayne Co., Missouri

Honey locust (Gleditsia triacanthos) – thornless individual

The tree in this post were photographed during November 2012 while hiking the Wappapello Section of the Ozark Trail in the Ozark Highlands of southeastern Missouri (Wayne Co.). 

Copyright © Ted C. MacRae 2013

His name is Ralph!

/ Ted C. MacRae / 15 Comments
E

Eastern hognose snake (Heterodon platirhinos) | Wayne Co., Missouri

Until the past few years, I could probably count on my two hands the number of snakes I’d seen in the field. This despite nearly weekly outings throughout each season going back to young adulthood. I’m sure this has something to do with my search image (beetles), my primary method of looking for them (whacking tree branches with my net handle over a beating sheet), and what I wasn’t also doing at the time (looking for snakes or anything else that wasn’t a beetle). One is unlikely to see these mostly shy, secretive animals when thrashing and whacking through the bush, and even if no ruckus is made to make them scamper they can still hide in plain sight due to their wonderfully cryptic coloration. It wasn’t until I started carrying a camera and began looking for other natural history subjects rather than just focusing on collecting as many beetles as possible that I began to see snakes. And since then I’ve seen a lot of them, including a terrifyingly aggressive timber rattler, a juvenile Osage copperhead, an uncooperative dusty hognosed snake, a death-feigning western hognosed snake, a cute little western pygmy rattlesnake, a rough green snake, a juvenile timber rattler, an adult Osage copperhead, and a yellow-bellied racer. The last three were all seen at what has become for me my favorite “snake spot”—a gorgeous preserve in the southeastern Missouri Ozarks. I’m not sure what makes this place so ideal—perhaps the massive outcroppings of jumbled rhyolite alongside the clear, spring-fed, gravel-bottomed river provide ample habitat and food for a variety of species. Regardless, I have visited the preserve each April  (for my annual season-opening birthday bug collecting trip) for the past three years and never failed to see at least one snake.¹

¹ To be clear, I am not a snake collector. That said, I do not have a problem with keeping snakes in captivity, at least in principle, but I am disturbed by the frequency with which snakes and other reptiles are irresponsibly collected at levels that are unsustainable and even “poached” from protected areas. For me personally, it is enjoyment enough to see, be able to identify, and observe these gorgeous animals in their native habitats, leaving with nothing more than a digital record and my vivid memories of that brief encounter.

Eastern Hognose Snake (Heterodon platirhinos) | Wayne Co., Missouri

When threatened, hognose snakes flatten their head and neck, puff up their body, and hiss loudly.

On my most recent visit, I was hoping to once again see one of the timber rattlers that inhabit these rocky hillsides. I tip-toed up and down the rocky slopes as quietly as I could, but no such luck. On the way back, however, I spotted this colorful eastern hognose snake (Heterodon platirhinos) lying just off the path. Despite its brilliant coloration and vivid markings, it was remarkably well camouflaged and I almost walked right past it. Of course, hognose snakes are well-known for their various threat and defensive displays. I’ve experienced some of these in my previous sightings with other species (death-feigning, mouth bleeding, and foul-smelling emissions), but to my delight I got to experience their most classic behaviors—flattening of the head and neck, puffing of the body, and loud hissing. The snake repeatedly performed these behaviors as I photographed it, and because I persisted the snake apparently concluded that these tactics weren’t working. What happened next was something I was completely unprepared for.

”Sir, what’s your name?”

As the snake began trying to crawl away, it opened its mouth widely…

”Uh, his name is…”

…and out came it’s last meal (obviously a frog, but with the head and front legs already digested, too difficult to identify any further)!

”RRRAAAALLPH!”

p.s. If you didn’t get the joke, watch this clip from the classic Cheech and Chong movie, Up in Smoke.

Copyright © Ted C. MacRae 2013

An elegant living fossil…

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In the insect world, hyperdiversity is the norm. More than a million species are known, and perhaps several million more await discovery. Beetles alone represent nearly a quarter of the earth’s described biota, with one genus (Agrilus in the family Buprestidae) bursting at the seams with more than 3,000 described species (Bellamy 2008). Biodiversity gone wild! While birders routinely field identify (and list) a majority of the birds they see to species, most insect enthusiasts are happy if they can simply identify their subjects to family—in most cases still leaving several hundred to several thousand possibilities for species identification. Even trained entomologists usually can identify only a tiny fraction of the insects they see and remain just as clueless about the vast majority of insects they encounter that don’t represent one of their limited number of study groups.

Pelecinus polyturator female | Wayne Co., Missouri

Pelecinus polyturator female | Wayne Co., Missouri

 Of course, that doesn’t mean field identification is impossible for all insects—certain groups such as butterflies, dragonflies, and tiger beetles lend themselves to field identification due to their relatively large size, bright colors, and distinctive markings. Many would also include the aculeate hymenopterans (i.e., “stinging” wasps and bees) among those groups for these same reasons. However, the vast majority of hymenopterans belong to a multitude of families characterized by tiny, parasitic species that seem (to this coleopterist’s eyes) to differ only in bafflingly minute details of wing venation and tibial spurs. (Honestly, I couldn’t tell you the difference between Tanaostigmatidae and Tetracampidae if my life depended on it!) Nevertheless, there are a small handful of parasitic hymenopterans in North America that are instantly recognizable due to their giant size (2 or more inches in length)—namely, Megarhyssa spp. (giant ichneumons) and the species shown in this post, Pelecinus polyturator (American pelecinid). Pelecinus polyturator is the only North American member of the family Pelecinidae, which itself contains only two additional species that are restricted to Mexico and Central/South America. It wasn’t always this way—fossils assignable to the family and representing 43 species in a dozen genera have been found as far back as the early Cretaceous (121–124 mya) across North America, Europe, and Asia (Grimaldi & Engel 2005). Surely this represents just the tip of the iceberg of Mesozoic and early Cenozoic pelecinid diversity, making today’s three species the last representatives of a once great lineage—”living fossils”¹ some might say.

¹ To ward off any scolding I might get from evolutionary purists, I get it; there is no such thing as a living fossil (except the T. rex skeleton in the movie “Night at the Museum”). I know that all species alive today have the same amount of evolutionary history behind them and are, if not from more immediate ancestors, highly derived compared to earlier life forms. I will admit that the term has become a bit overused as pseudoscientific shorthand for branding an organism as ‘primitive’ (another term which tends to raise hackles); however, I don’t see the problem with its use as informal reference to relatively ancient groups, usually more diverse in the past and now represented by only a few species. Innocuous shorthand is all it is.

This elegant female, recognizable by her extraordinarily narrowly elongate abdomen (males have a somewhat shorter abdomen that is widened at the end), was seen back in July 2011 as she flew to a blacklight and landed on nearby foliage in a mesic bottomland forest in southeastern Missouri’s Ozark Highlands. I have seen females on occasion over the years but have not yet seen a male, which are increasingly rare in more northern latitudes of the species distribution. I missed the focus a bit on this photo (and also the other half-dozen or so shots that I took)—photographing an active subject at night on elevated foliage without a tripod is difficult to say the least! Nevertheless, after post-processing it’s a decent photograph. If you are wondering why it took me so long to post it, that’s because only recently have I gained the confidence to “clean up” poorly exposed photos where the subject and/or substrate on which they are resting is so distractingly littered with debris as this:

Yuk!!!

Yuk!!!

Compare the original photo here to the final photo above it—how many post-processing tools can you detect the use of? 🙂

REFERENCES:

Bellamy, C. L. 2008. World catalogue and bibliography of the jewel beetles (Coleoptera: Buprestoidea), Volume 4: Agrilinae: Agrilina through Trachyini. Pensoft Series Faunistica 79:1–722.

Grimaldi, D. and M. S. Engel. 2005. Evolution of the Insects.Cambridge University Press, New York, xv + 755 pp.

Copyright © Ted C. MacRae 2013

Cicindela 44(3–4) is issued

/ Ted C. MacRae / Leave a comment

Cicindela_44(3-4)

The latest issue of the journal Cicindela arrived in my mailbox yesterday, and it’s safe to say that I’ve got the issue “covered.” The issue features three papers, one of which documents my recent encounter with Cicindelidia ocellata rectilatera (Reticulated Tiger Beetle) in Arkansas (MacRae 2012), the first confirmed occurrence of the subspecies in that state and a northeastern extension of its known range. (This paper is an expansion of my post Just repanda… er, wait a minute…) Normally restricted to (though abundant in) Texas and New Mexico (Pearson et al. 2006), the only previous records of this subspecies east of Texas are at two localities near the eastern side of the Sabine River dividing Texas and Louisiana (Graves & Pearson 1973). More recently, however, the subspecies was also recorded just north of Texas in southwestern Oklahoma Schmidt 2004). Whether these recent extensions to its known range reflect an expanding distribution or are merely artifacts of sampling is unknown; however, one of the Arkansas localities has been visited frequently by tiger beetle enthusiasts over the years, as it is a known locality for the very attractive Cicindela formosa pigmentosignata (Reddish-green Sand Tiger Beetle), lending some support to the range expansion hypothesis.

In addition to the paper, one of the photographs that I took of C. ocellata rectilatera in Arkansas graces the cover of the issue.

Two other papers are also contained in the issue, one documenting an additional occurrence of Opisthencentrus dentipennis in Brazil by Ron Huber (2012), and another by Kristi Ellingsen featuring photographs and habitat description for the first tiger beetle to be found in Tasmania, Australia (Ellingsen 2012). A truly international journal!

Lastly, please consider subscribing to Cicindela. Subscription rates are only $10 in the U.S. and $13 outside of the U.S., amounts that even the most casually interested can justify! Also, if you have a more serious interest in tiger beetles, I hope you’ll consider submitting a manuscript for consideration. Subscription information and editorial policy can be found inside the front cover of a recent issue or at this post.

REFERENCES:

Ellingsen, K. 2012. Discovery of the first tiger beetle found on the island of Tasmania, Australia. Cicindela 44(3–4):55–57.

Graves, R. C. & D. L. Pearson. 1973. The tiger beetles of Arkansas, Louisiana, and Mississippi (Coleoptera: Cicindelidae). Transactions of the American Entomological Society 99(2):157–203.

Huber, R. L. 2012. Another locality record for Opisthencentrus dentipennis (Germar) in Brazil. Cicindela 44(3–4):55–57.

MacRae, T. C. 2012. Occurrence of Cicindelidia ocellata rectilatera (Chaudoir) (Coleoptera: Cicindelidae) in Arkansas. Cicindela 44(3–4):49–54.

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.

Schmidt, J. P. 2004. Tiger beetles of Fort Sill, Comanche County, Oklahoma, with a new state record for Cicindela ocellata rectilatera Chaudoir. Cicindela 36:1–16.

Copyright © Ted C. MacRae 2013