jewel beetles

Mexico 1992—Gang of Ten

/ Ted C. MacRae / 3 Comments

As a young collector attracted to woodboring beetles, my interests were split evenly between the families Buprestidae and Cerambycidae. In those early days, I actively sought the counsel of experts in both families, looking for help with identifications. Most were more than gracious with their help, and receiving their letters and return shipments of beetles I had sent for their examination was a highlight of each winter season. There was one man, however, whose letters and parcels I looked forward to receiving more than any other—the late, great Gayle Nelson. More than just a report of identifications, Gayle’s letters were also rich with advice, suggestions and encouragement—he became my first mentor. I coauthored my first published paper on Buprestidae with Gayle (Nelson & MacRae 1990), and when I moved to California in 1990 I had the chance to meet him in person and accompany him on a collecting trip to the great southern Californian deserts. Talk about learning from the master! In the meantime I had also struck up correspondence with long-time buprestophiles Rick Westcott and Chuck Bellamy. I guess between the three of them they saw some potential in me, as shortly after my move to California they invited me to join the upcoming World Buprestid Workers Gathering—a 2-week collecting trip in southern Mexico scheduled for July 1992. While not all of the world’s buprestid workers were able to make this trip, a majority of the heaviest hitters from the U.S. and Europe were there. The photo below is the only one I’m aware of in which all ten participants are present, and while I felt like a midget amongst giants at the time, I’ve enjoyed more or less regular correspondence with most of the participants of that trip over the many years that have since passed.

Huahuapan de Leon, Oaxaca, Mexico - July 1992 (L to R): Ted MacRae, Rick Westcott, Hans Mühle, Chuck Bellamy, Gayle Nelson, Byrd Dozier, Dave Verity, Kim Pullen, Svata Bílý, Mark Volkovitsh (photographer unknown).

Huahuapan de Leon, Oaxaca, Mexico—July 1992 (left to right): Ted MacRae, Rick Westcott, Hans Mühle, Chuck Bellamy, Gayle Nelson, Byrd Dozier, Dave Verity, Kim Pullen, Svata Bílý, Mark Volkovitsh.

That trip remains one of the best insect collecting trips I’ve ever experienced (although there are many others now that also bear that distinction). Gayle, Dave Verity and I started in the state of Guerrero and worked our way down into Oaxaca, where we met up with the others and collected together as one large group before Chuck, Rick and I split off and returned for more collecting in Guerrero. I don’t remember how many species I collected—somewhere in the neighborhood of 60 or so, but I’ll never forget finding the first specimens of what would eventually be described as Oaxacanthaxia nigroaenea Nelson & MacRae 1994. We found it at the type locality (near Tehuantepec) of what was then the only known species in the genus, O. viridis Bellamy 1990, that represented an apparently relictual line of buprestids with affinities to certain Old World genera. While that was the only new species that I described from the trip, several described by others are based at least in part on material that I collected. Another highlight of the trip was the “big, dead tree” in Cañón del Zopilote, Guerrero (literally, a big, dead tree), the high branches of which yielded several specimens of Polycesta cortezii Thomson 1878 and one Jelinekia barri (Nelson 1975). Sadly, I wasn’t much of a journal-keeper in those days, so most of the memories that remain from that trip are just snippets in time. Nevertheless, whenever I look at specimens collected on that trip I am usually able to recall the circumstances of its collection, and I recently had the chance to go through much of this material in detail again, as many of the specimens collected represented newly documented state occurrences and adult host plants. These records can now be found in a newly published paper by me and Chuck in which two new species of Actenodes collected during subsequent trips are described (MacRae & Bellamy 2013).

REFERENCES:

MacRae, T. C. & C. L. Bellamy. 2013. Two new species of Actenodes Dejean (Coleoptera: Buprestidae) from southern Mexico, with distributional and biological notes on Buprestidae from Mexico and Central America. The Pan-Pacific Entomologist 89(2):102–119.

Nelson, G. H. & T. C. MacRae. 1990. Additional notes on the biology and distribution of Buprestidae (Coleoptera) in North America, III. The Coleopterists Bulletin 44(3):349–354.

Nelson, G. H. & T. C. MacRae. 1994. Oaxacanthaxia nigroaenea Nelson and MacRae, a new species from Mexico (Coleoptera: Buprestidae). The Coleopterists Bulletin 48(2):149–152.

Copyright © Ted C. MacRae 2013

The perfectly polyphagous Chrysobothris purpureovittata

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Chrysobothris purpureovittata on Celtis sp. | Gloss Mountains State Park, Woodward Co., Oklahoma

Chrysobothris purpureovittata Horn 1886 | Gloss Mountains State Park, Woodward Co., Oklahoma

Many species of jewels beetles in North America are known for having some degree of host specificity. This is especially true of species in the genus Chrysobothris, whose members are often restricted to a particular family, genus, or even species of host plant. There are some, however, that are not so fastidious in their choice of host plant, and perhaps the best example of such is the species Chrysobothris purpureovittata. This pretty and not uncommonly collected species has been associated with well over two dozen species of deciduous trees representing 21 genera in eleven plant families.

Chrysobothris purpureovittata

Interestingly, the extent of this species’ polyphagy has not been fully appreciated until recently. At the time of Fisher’s (1942) revision of North American species, the only recorded larval hosts were elm (Ulmus sp.) and plum (Prunus sp.). Numerous adult hosts—i.e., plants on which adults had been collected only—were recorded in subsequent years, first by Vogt (1949) in south Texas and later by Nelson et al. (1982) from other locations. However, it was not until my Missouri jewel beetle survey (MacRae 1991) and subsequent “notes papers” by me and colleagues (MacRae & Nelson 2003, MacRae 2006, Wellso & Jackman 2006) that the true diversity of larval hosts became known. A majority of the larval host records are from the Ulmaceae, including several species of hackberry (Celtis tenuifolia, C. laevigata, C. ehrenbergia, C. reticulata) and cedar elm (Ulmus crassifolia), suggesting that despite its polyphagous nature there is some preference for members of this plant family. On my recent early June trip to northwestern Oklahoma, I encountered this species at several localities as abundantly as I can ever recall, with nearly all of them beaten from hackberry.

Chrysobothris purpureovittata

Chrysobothris purpureovittata is distributed primarily in the central and south-central U.S., with records from Indiana west to Kansas and south to Mississippi and northern Mexico. A population at the western edge of its distribution (Cloudcroft, Otero Co., New Mexico) associated with mountain mahogany (Cercocarpus montanus) was recently described as a separate subspecies (C. purpureovittata cercocarpi) by Westcott & Nelson (2000)—it is distinguished from nominotypical populations by the entirely red pronotum and uniformly dark elytra.

Chrysobothris purpureovittata

REFERENCES:

Fisher, W. S. 1942. A revision of North American species of buprestid beetles belonging to the tribe Chrysobothrini. U. S. Department of Agriculture, Miscellaneous Publication 470, 1–275.

MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri.  Insecta Mundi 5(2):101–126.

MacRae, T. C. 2006. Distributional and biological notes on North American Buprestidae (Coleoptera), with comments on variation in Anthaxia (Haplanthaxia) viridicornis (Say) and A. (H.) viridfrons Gory. The Pan-Pacific Entomologist 82(2):166–199.

MacRae, T. C. and G. H. Nelson. 2003. Distributional and biological notes on Buprestidae (Coleoptera) in North and Central America and the West Indies, with validation of one species. The Coleopterists Bulletin 57(1):57–70.

Nelson, G. H., D. S. Verity & R. L. Westcott. 1982. Additional notes on the biology and distribution of Buprestidae (Coleoptera) of North America. The Coleopterists Bulletin 35(2) [1981]:129–152.

Vogt, G. H. 1949. A biologically annotated list of the Buprestidae of the Lower Rio Grande Valley, Texas. Annals of the Entomological Society of America 42(2):192–202.

Wellso, S. G. & J. A. Jackman. 2006. A new species of Anthaxia (Haplanthaxia) Reitter (Coleoptera: Buprestidae) and new North American buprestid distributional and host records. The Pan-Pacific Entomologist 82(2):262–268.

Westcott, R. L. & G. H. Nelson. 2000. Descriptions of two new species of Acmaeodera Eschscholtz, and two new subspecies of Agrilus Curtis and Chrysobothris Eschscholtz (Coleoptera: Buprestidae) in North America, with detailed notes on others. The Coleopterists Bulletin 54(3):300–312.

Copyright © Ted C. MacRae 2013

The ever-increasing diversity of Oklahoma beetles

/ Ted C. MacRae / 8 Comments

My idea to return to Oklahoma’s Gloss Mountains this spring actually began taking shape during last year’s fall visit to the area, when I found a single Chrysobothris octocola adult on a dead mesquite (Prosopis glandulosa) branch. While common across the southwestern U.S. in association with this plant, its occurrence in the Gloss Mountains represented a northeastern range extension and new state record for Oklahoma! On that same trip I also collected an interesting beetle in the family Rhipiphoridae representing the species Toposcopus wrightii—also not previously recorded in the literature from Oklahoma. Combined with finding Acmaeodera macra here the previous year, it was becoming clear to me that area held good potential for other more typically southwestern species of wood boring beetles. Although I had by then visited the area several times, most of these visits were more focused on tiger beetles rather than wood boring beetles. If I could find such interesting species of wood boring beetles when I wasn’t focused on them, imagine what I might find if I timed a visit in late spring when such species should be at their peak of adult activity.

Chrysobothris quadrilineata | Gloss Mountains State Park, Major Co., Oklahoma

Chrysobothris quadrilineata | Gloss Mountains State Park, Major Co., Oklahoma (new state record).

Of course, success came quickly during this early June visit. I immediately found C. octocola common on the mesquite and would collect a nice series of voucher specimens before the day was over, and the second species I encountered, also on mesquite, was the longhorned beetle Plionoma suturalis—another new state record! I spent a bit of time working the mesquite, and when I had collected a sufficient series of both species, I turned my attention to the eastern red-cedars (Juniperus virginiana) in the area. Actually, I had had my eye on the red-cedars since last fall, when I noticed that nearly every tree had dead branches mixed in amongst the living branches. Closer examination revealed the workings of jewel beetle larvae in all of these dead branches, and a few larvae typical of the genus Chrysobothris were cut from one of the branches. A common species in the Great Plains associated with Juniperus is C. ignicollis, but these larvae looked rather big to represent that species, so I bundled up some dead branches and brought them back home for rearing but forgot to check on them before I left on this trip. At any rate, I walked up to one of the red-cedars, placed my beating sheet under a dead branch, gave the branch a whack with the handle of my net, and onto the sheet fell a rather robust Chrysobothris that I didn’t immediately recognize. I knew it wasn’t C. ignicollis, a much smaller species that I have collected on numerous occasions, so I thought maybe it could be C. texana, another western Juniperus-associate that I’ve collected less commonly. Still, the robust body and broad, distinct elytral and pronotal ridges had me second guessing that identification (especially after I found some individuals that looked more like what I remembered C. texana looking like). Over the next two days I beat hundreds (literally!) of dead juniper branches, finding many C. ignicollis but every now and then getting also one of these big, robust individuals.

Chrysobothris quadrilineata

Adults were beaten from dead branches on live Juniperus virginiana (new adult host).

After returning home, I checked my heavily annotated copy of Fisher (1942) and quickly determined the robust specimens as representing C. quadrilineata—a rather uncommon species and one that I’d never collected before. Described by LeConte in 1860 from New Mexico and recorded early in the 20th century from Arizona, Nevada and California, it has in more recent years been found to occupy a rather wide distribution across the western U.S., including Texas (Barr & Westcott 1976), Colorado, Oregon, South Dakota (Nelson et al. 1982), and Utah (Nelson 1987). Notice one state that is not in that list—Oklahoma! That’s right, another new state record! I later found photographs of this species on BugGuide taken in the very same area a year earlier (7 June 2012).

Chrysobothris quadrilineata

Adults also emerged from dead J. virginiana branches collected Sept. 2012 (first reported larval host).

When I returned home, I also checked the rearing cans and found several adults had emerged from the branches I collected last September. The only host associations that have been recorded for this species are adults collected on Juniperus californica (Linsley & Ross 1940) and J. pachyphloea [= J. deppeana] (Barr & Westcott 1976). Thus, J. virginiana not only represents a new host record for the species but is also the first known larval host. Considering how broadly distributed across the western U.S. this species is, it seems likely that it utilizes a number of Juniperus spp. throughout its range.

REFERENCES:

Barr, W. F. & R. L. Westcott. 1976. Taxonomic, biological and distributional notes of North American Chrysobothris, with description of a new species from California (Coleoptera: Buprestidae).  The Pan-Pacific Entomologist 52(2):138–153.

Fisher, W. S. 1942. A revision of North American species of buprestid beetles belonging to the tribe Chrysobothrini. U. S. Department of Agriculture, Miscellaneous Publication 470, 1–275.

Linsley, E. G. & E. S. Ross. 1940. Records of some Coleoptera from the San Jacinto Mountains, California.  The Pan-Pacific Entomologist 16(2):75–76.

Nelson, G. H. 1987. Additional notes on the biology and distribution of Buprestidae (Coleoptera) in North America, II.   The Coleopterists Bulletin 41(1):57–65.

Nelson, G. H., D. S. Verity & R. L. Westcott. 1982. Additional notes on the biology and distribution of Buprestidae (Coleoptera) of North America.  The Coleopterists Bulletin 35(2) [1981]:129–152.

Copyright © Ted C. MacRae 2013

Agrilus fuscipennis on Persimmon

/ Ted C. MacRae / 10 Comments

Agrilus fuscipennis

Agrilus fuscipennis may not be the largest or the prettiest member of the genus occurring in Missouri (that honor is reserved for Agrilus concinnus, or “hibiscus jewel beetle”—MacRae 2004). Nevertheless,  it comes pretty darned close! Add to that the fact that it is among our most seldom encountered jewel beetles, and you can understand how excited I was to see this species on my sheet after beating a small persimmon (Diospyros virginiana) tree last weekend at Hercules Glades Wilderness in the White River Hills of extreme southwestern Missouri. In fact, I have only collected this species three times previously—all single specimens beaten from persimmon, and all back in the 1980s!

Agrilus fuscipennis

Jewel beetles are unquestionably popular among insect collectors, due no doubt in large part to their vivid, metallic colors. I think the family, however, would be even more popular were it not for the genus Agrilus. Fully one in five species of jewel beetles belongs to this genus, which at nearly 3,000 described species and counting (Bellamy 2008) is perhaps the largest genus in the entire animal kingdom. As might be expected, such hyperdiversity has resulted in taxonomic quagmire, with species limits difficult to define and many hardly distinguishable except by examination of male genitalia (MacRae 2003). Additionally, in contrast to the rest of the family which is generally recognized as containing some of the most spectacularly beautiful beetles in the world, the most species of Agrilus are small, usually less than 8 mm in length and often as small as only 4–5 mm, and also lack the vivid colors (at least, to the naked eye) for which the rest of the family is so noted.

Agrilus fuscipennis

Agrilus fuscipennis is one of several species that buck this general Agrilus theme. While not forming a discrete taxonomic group within the genus, they are all unified by the following characteristics: 1) relatively large for the genus (A. fuscipennis measures 12–14 mm length), 2) vivid red pronotum and black elytra, and 3) mine the lower trunks, crown and main roots of living rather than dead host plants. For A. fuscipennis the larval host is persimmon, and other similar species include A. vittaticollis on serviceberry (Amelanchier) and A. concinnus on wild hibiscus (Hibiscus). These other species also are not very commonly encountered, at least in my experience, perhaps partly because they are not as easily reared from their hosts as species that develop as larvae in dead wood (the latter can be easily reared by retrieving infested wood from the field and placing in containers to trap emerging adults).

Agrilus fuscipennis

In the interest of full disclosure, these photos were taken in the studio after returning home. Although the persimmon branch is real, the “blue sky” is actually just a colored index card. I prefer to photograph insects in the field, especially with insects such as tiger beetles where it is desirable to include elements of the insect’s natural habitat in the photograph. However, I don’t have a problem with studio photography if field photographs prove too difficult or time-consuming or present too high a risk of escape by a prize specimen. My normal protocol for the latter is to place the first individual in a vial and continue to search for another that I will then try to photograph in the field. If that doesn’t work then I still have the first individual as a backup for studio photographs. In the case of this beetle, I found it on the very first clump of persimmon that I beat but never saw another despite beating persimmon for the rest of the afternoon (just like the three I found separately back in the 80s)! I have plans to photograph A. concinnus later this summer on its Hibiscus host plant in southeastern Missouri—hopefully I will succeed in getting true field photographs of that species.

Agrilus fuscipennis

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.

MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri.  Insecta Mundi 5(2):101–126.

MacRae, T. C. 2004. Beetle bits: Hunting the elusive “hibiscus jewel beetle”. Nature Notes, Journal of the Webster Groves Nature Study Society 76(5):4–5.

Copyright © Ted C. MacRae 2013

Oversized, double-concave diffuser for MT-24EX twin flash

/ Ted C. MacRae / 12 Comments
IMG_2865_enh_1080X720

Megaloxantha bicolor palawanica, photographed with oversized, double-concave diffuser

This jewel beetle is, of course, Megaloxantha bicolor palawanica me beetle on several occasions while testing out different diffuser designs for my Canon MT-24EX twin flash unit. In the most recent one, I had tried combining SoftBoxes with my oversized concave diffuser and was pleased enough with the result that I thought I might try it in the field. Well, let’s just say the extensions for the flash heads and SoftBoxes attached to them was far too clumsy for field use, and I abandoned the idea after just a couple of hours. Back to the drawing board.

Despite the problems with using the SoftBoxes in the field, I still wasn’t ready to give up on the idea of double diffusion, and I had also learned that extending my oversized diffuser out over the subject (leaving it “open”) produced better lighting than curling it back (as I had been doing). Curling the diffuser back only served to turn it into a convex diffuser, which results in more specular highlighting because the center of the diffuser is closer to the subject than the edges. A concave diffuser provides more even lighting because all parts of the diffuser are roughly the same distance from the subject. Just about that time, I saw a DIY diffuser design by Piotr Nascrecki that, in principle, resembled Alex Wild‘s tent diffuser. It was, however, much larger—like mine, and thus amenable for use with a 100mm macro lens (the macro lens I use most commonly). This resemblance to Alex’s diffuser did make me notice one missing feature—double diffusion layers. That’s when I thought, why not do the same with an oversized diffuser rather than fussing with separate diffusers attached to the flash heads? I had some Bogen Imaging filter sheets on hand (#129 Heavy Frost), so I picked up some 1-mm steel wire at the hardware store, found a Bic pen in the drawer that I could cut in half, and built the diffuser as shown in Piotr’s post. I then secured a second filter sheet above the first sheet by taping the two together along their sides, being sure to ‘bow’ the upper sheet above the bottom sheet to achieve the double diffusion effect. Here is the result (please excuse the iPhone shots):

Oversized double diffuser for Canon MT-24EX twin flash.

Canon 50D with MT-24EX twin flash and oversized, double-concave diffuser.

IMG_0939_enh_1080X720

Better view of the double diffusion layers and Piotr’s “Bic pen” attachment system.

I have big hopes that this will finally be the diffuser I’ve been looking for. For as quick a test shot as the jewel beetle photo above was, the lighting is great and the colors are vibrant—both achieved with typical post-processing. My only complaint is the slightly greater “hot spot” intensity in the lower parts of the highlights in the eyes. This is due to the flash heads sitting near the base of the diffuser, and (as Piotr recommends) a second set of Kaiser shoes will allow me to move the flash heads not only more towards the center of the diffuser but also further above it to help spread out the light throw and even out the highlights. I’ll need to play around positioning the flashes to figure out the best positions depending on the size and distance of the subject—sitting up higher as they are puts them more on “top” than in “front” of the subject, so they will need to be directed downward more than I am used to doing. Even more important, however, is field usability, and I really think this diffuser will prove to be convenient and easy to use in the field—no more gawky arms attached to the camera, the diffuser attaching quickly and easily and, just as importantly, coming off easily and storing flat in the backpack, and large enough to do the job while not so oversized that it gets in the way. Piotr says this diffuser also works well with the 65mm macro lens, so I will certainly be testing that out as well.

Copyright © Ted C. MacRae 2013

A jewel of a beetle

/ Ted C. MacRae / 13 Comments

I really wish I had a photomicrography setup like the one that Sam Heads has at the University of Illinois for imaging preserved specimens. Alas, insect taxonomy is “just a hobby” for me, and any specimen photography I wish to do must be done with my field camera equipment. Of course, poverty prompts creativity (not that I consider a Canon 50D with an MP-E 65mm macro lens and MT-24EX twin flash unit a sign of poverty), and after a bit of tinkering and fiddling I’ve figured out a way to setup the specimen and flash units to create images of pinned specimens that I think are more than adequate for publication in taxonomic papers.

Here is one I did recently of the jewel beetle Actenodes calcaratus (family Buprestidae). This species is broadly distributed from the southwestern U.S. through Mexico and into Central America, where it breeds in dead branches of a variety of mostly fabaceous trees such as Acacia and Prosopis. During several trips to southern Mexico in recent years, Chuck Bellamy and I collected two new species of Actenodes that look very similar to A. calcaratus but differ in several important characters, primarily surface sculpture, the form and male coloration of the face, and male genitalia. A manuscript describing these two species and containing this and similar images of the new species was recently submitted for publication. Though not quite as razor-sharp as images created through focus-stacking processes, it still shows good detail and even lighting. What do you think?¹

¹ For those who find the pin head distracting, I am not a proponent of cloning out pin heads, debris, or other imperfections on images of preserved specimens in taxonomic papers. Other enhancements such as levels, sharpness, contrast, etc. are fine since these are all influenced greatly by lighting, but otherwise I believe the specimen needs to be presented exactly as it appears. A possible alternative is to remove the pin for imaging, but this presents a risk of damage to the specimen that is of questionable benefit in the case of non-type specimens—and downright irresponsible for primary types. Another alternative is to thoroughly clean and image the specimen prior to mounting, but this is rarely feasible as in most cases it is only after the specimen is mounted and studied further that its status as a new species is realized.

Actenodes calcaratus | MEXICO: Guerrero, Hwy 95, 5 km S Milpillas, 7.vii.1992, "big dead tree", G. H. Nelson [FSCA]. Male plesiotype.

Actenodes calcaratus | MEXICO: Guerrero, Hwy 95, 5 km S Milpillas, 7.vii.1992, “big dead tree”, G. H. Nelson [FSCA]. Male plesiotype.

Copyright © Ted C. MacRae 2013

Backyard gems

/ Ted C. MacRae / 12 Comments

I’ve been fortunate to have the chance to travel far and wide in my searches for insects—from the Gypsum Hills of the Great Plains and Sky Islands of the desert southwest to the subtropical riparian woodlands of the Lower Rio Grande Valley, tropical thorn forests of southern Mexico and veld of southern Africa. No matter how far I travel, however, I’m always happy to return to the Missouri Ozarks. It is here where I cut my entomological teeth so many years ago, and though I’ve now scrabbled around these ancient hills for more than three decades it continues to satisfy my thirst for natural history. Though not nearly as expansive as the Great Plains, there are nevertheless innumerable nooks and crannies nestled in the Ozarks, and I find myself constantly torn between looking for new spots (it would take several lifetimes to find them all) and going back to old favorites. Living in the northeastern “foothills” in the outskirts of St. Louis provides an ideal vantage for exploration; however, sometimes I am truly amazed at the natural history gems that can be found within a stone’s throw from my house. Some examples I’ve featured previously include Shaw Nature Reserve, home to a hotspot of the one-spotted tiger beetle, Castlewood State Park, where I found a gorgeously reddish population of the eastern big sand tiger beetle, and Victoria Glades Natural Area, site of the very first new species (and perhaps also the most beautiful) that I ever collected.

Englemann Woods Natural Area | Franklin Co., Missouri

Today I found another such area—Englemann Woods Natural Area, and at only 5 miles from my doorstep it is the closest natural gem that I have yet encountered. One of the last old-growth forests in the state, its deep loess deposits on dolomite bedrock overlooking the Missouri River valley support rich, mesic forests on the moister north and east facing slopes and dry-mesic forests on the drier west-facing slopes dissected by rich, wet-mesic forests with their hundreds-of-years-old trees. A remarkable forest of white oak, ash, basswood and maple in an area dominated by monotonous second-growth oak/hickory forests.

Englemann Woods Natural Area

Steep north-facing slopes border the Missouri River valley.

It is not, however, the 200-year-old trees that will bring me back to this spot, but rather the understory on the north and east-facing slopes. Here occur some of the richest stands of eastern hornbean (Ostrya virginiana) that I have ever seen. This diminutive forest understory inhabitant is not particularly rare in Missouri, but as it prefers rather moist upland situations it is not commonly encountered in the dry-mesic forests that dominate much of the Ozarks. Stands of this tree, a member of the birch family (Betulaceae) are easy to spot in winter due to their habit of holding onto their dried canopy of tawny-brown leaves (see photo below).

Englemann Woods Natural Area

Rich stands of eastern hornbeam (Ostrya virginiana) dominate the north- and east-slope understory.

Why am I so interested in this plant? It is the primary host of the jewel beetle species Agrilus champlaini. Unlike most other members of the genus, this species breeds in living trees rather than dead wood, their larvae creating characteristic swellings (galls, if you will) on the twigs and stems as they spiral around under the bark feeding on the cambium tissues before entering the wood to pupate and emerge as adults in spring. This species is known in Missouri from just two specimens, both collected by me way back in the 1980s as they emerged from galls that I had collected during the winter at two locations much further away from St. Louis. The presence of this rich stand of hornbeam just 5 miles from my home gives me the opportunity to not only search the area more thoroughly to look for the presence of galls from which I might rear additional specimens, but also to look for adults on their hosts during spring and (possibly, hopefully) succeed in photographing them alive.

Englemann Woods Natural Area

Inside the “hornbeam forest.”

Another “draw” for me is the restoration work that has begun on some of the west-facing slopes in the areas. Pre-settlement Missouri was a far less wooded place than it is today, as evidenced by the richly descriptive writings penned by Henry Schoolcraft during his horseback journey through the Ozarks in the early 1800’s. At the interface between the great deciduous forests to the east and the expansive grasslands to the west, the forests of Missouri were historically a shifting mosaic of savanna and woodland mediated by fire. Relatively drier west-facing slopes were more prone to the occurrence of these fires, resulting in open woodlands with more diverse herbaceous and shrub layers. At the far extreme these habitats are most properly called “xeric dolomite/limestone prairie” but nearly universally referred to by Missourians as “glades”—islands of prairie in a sea of forest! I have sampled glades extensively in Missouri over the years, and they are perhaps my favorite of all Missouri habitats. However, it is not future glades or savannas that have me excited about Englemann Woods but rather the availability of freshly dead wood for jewel beetles and longhorned beetles resulting from the selective logging that has taken place as a first step towards restoration of such habitats on these west-slopes. The downed trees on these slopes and subsequent mortality of some still standing trees that is likely to result from the sudden exposure of their shade adapted trunks to full sun are likely to serve as a sink for these beetles for several years to come. I will want to use all the tools at my disposal for sampling them while I have this opportunity—beating, attraction to ultraviolet lights, and fermenting bait traps being the primary ones. It looks like I’d better stock up on molasses and cheap beer!

Englemann Woods Natural Area

Restoration efforts on the west-facing slopes begins with selective logging.

Eastern red-cedar (Juniperus virginiana) is native to Missouri, but in our time it has become a major, invasive pest tree. The suppression of fire that came with settlement also freed this tree from a major constraining influence on its establishment in various habitats around the state, primarily dolomite/limestone glades. Nowadays most former glade habitats, unless actively managed to prevent it, have become choked with stands of this tree, resulting in shading out of the sun-loving plants that historically occurred much more commonly in the state. Untold dollars are spent each year by landscape managers on mechanical removal and controlled burns to remove red-cedar and prevent its reestablishment in these habitats. There is one habitat in Missouri, however, in which eastern red-cedar has reigned supreme for centuries or possibly millenia—dolomite/limestone bluff faces.

Juniperus virginiana

Craggly, old Eastern red-cedars (Juniperus virginiana) cling tenaciously to the towering dolomite bluffs.

With little more than a crack in the rock to serve as a toehold, red-cedars thrive where no other tree can, growing slowly, their gnarled trunks contorted and branches twisted by exposure to sun and wind and chronic lack of moisture. Some of the oldest trees in Missouri are red-cedars living on bluffs, with the oldest example reported coming from Missouri at an incredible 750–800 years old. There is something awe-inspiring about seeing a living organism that existed in my home state before there were roads and cars and guns. These ancient trees are now an easy drive from my house (though a rather strenuous 300-ft bushwhacking ascent to reach the bluff tops)—they seem ironically vulnerable now after having endured for so long against the forces of nature. For me, they will serve as a spiritual draw—a reason to return to this place again regardless of what success I might have at finding insects in the coming months.

Juniperus virginiana

This tree may pre-date Eurpoean settlement.

Aplectrum hyemale

Adam-and-Eve orchid (Aplectrum hyemale).

Copyright © Ted C. MacRae 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:

IMG_2095_enh_1080x720

Original post-processing

IMG_2095_enh2_1080x720

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