Tennessee

The lesser of two jewels

/ Ted C. MacRae / 1 Comment
Chrysobothris dentipes on exposed root of Pinus virginiana | South Cumberland State Park, Tennessee

Chrysobothris dentipes on exposed root of Pinus virginiana | South Cumberland State Park, Tennessee

A couple of months ago I wrote a post about Chrysobothris orono, a magnificent jewel beetle that I had the opportunity to see earlier in the year. Fellow buprestophile Joshua Basham and his colleague Nadeer Youssef had managed to find this very uncommonly encountered species breeding in exposed roots of Virginia pine (Pinus virginiana) on the edges of high bluff tops in South Cumberland State Park, Tennessee. I traveled to the site with them this past May and was rewarded with one specimen of the species, two Buprestis species that I’d not collected before (B. striata and B. salisburyensis), several photographs of each, and numerous memories. Chrysobothris orono was not, however, the only species in the genus seen that day. We also encountered numerous individuals of another species, Chrysobothris dentipes, on the same Virginia pines that were hosting C. orono, B. striata, and B. salisburyensis. Like C. orono, nearly all of the individuals seen were not on the trunks and branches of the pines, but on dead, exposed roots of the pines.

Presumed Chrysobothris dentipes adult emergence hole in exposed root of Virginia pine.

Presumed Chrysobothris dentipes adult emergence hole in exposed root of Virginia pine. Note pile of frass on the ground below the hole, suggesting that the adult emerged shortly before this photo was taken.

Unlike C. orono, however, which has only been recorded from a handful of states/provinces along the eastern seaboard and around the Great Lakes (and, now, Tennessee—MacRae & Basham 2013), C. dentipes is one of the widest ranging species in the genus, occurring throughout much of the U.S. & Canada and even the West Indies and northern Mexico (Fisher 1942). Throughout this expansive range, C. dentipes larvae develop in dead pine wood, although they have been reared also from tamarack (Larix laricina) and balsam fir (Abies balsamea) (Fisher 1942, Dearborn & Donahue 1993). I remember my excitement at collecting this species for the first time back in the 1980s in Missouri on log piles and slash from logging operations in the shortleaf pine (Pinus echinata) forests of southern Missouri. Eventually I realized how common and widespread a species it is, as it was the one species I could almost always count on seeing whenever I examined recently dead pines wherever I went.

The flattened body, dull coppery color, and partly yellow antennal segments make this a distinctive eastern U.S. species.

The flattened body and partly yellow antennal segments make this a distinctive species in the field.

The specific epithet (“denti-” meaning tooth, and “pes” meaning foot) apparently refers to the large spine on the front femora, although many species of Chrysobothris exhibit this character. This was one of the earliest described species in the genus, so perhaps other species with spined femora hadn’t been seen yet, or maybe the name refers to the toothed outer margin of the femoral spine rather than the spine itself. In any case, the species is rather distinctive and easy to identify in the field by its moderately large size, somewhat flattened body, and overall matte appearance. The clincher are the antennae, which may not be easy to see in the field but, unlike any but a few other very dissimilar species, have the outer segments partly brownish-yellow in color. Like most Chrysobothris species, adults are very “zippy” and alert in the field, the males running rapidly in short bursts when searching logs for females and both sexes quick to take flight when approached. While the adults in these photos are fairly conspicuous on the wood on which they are sitting, their coloration and surface sculpturing actually serve a cryptic function and make them very difficult to spot on rough pine bark where they are normally encountered.

REFERENCES:

Dearborn, R. G. & C. P. Donahue. 1993. An annotated list of insects collected and recorded by the Maine Forest Service, order Coleoptera, beetles. Maine Forest Service, Department of Conservation, Insect and Disease Division No. 32, 102 pp.

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.

MacRae, T. C. & J. P. Basham. 2013. Distributional, biological, and nomenclatural notes on Buprestidae (Coleoptera) occurring in the U.S. and Canada. The Pan-Pacific Entomologist 89(3):125–142 [pdf].

© Ted C. MacRae 2014

The Buprestis tree

/ Ted C. MacRae / 6 Comments

After collecting Chrysobothris seminole at the type locality in Georgia and Chrysobothris orono the following day at South Cumberland State Park in Tennessee, I thought my trip last May with fellow buprestophiles Josh Basham and Nadeer Youseff was a complete success. I had collected two species of jewel beetles (family Buprestidae) that I had never collected before—not an easy thing for me to do in the eastern U.S. now after three decades of collecting, but little did I know that I would go on to collect three additional such species that same day. We had only seen two C. orono individuals after a fair bit of searching on the exposed roots of the Virginia pines (Pinus virginiana) growing along the blufftops, but I’ve learned to be tenacious and not give up too quickly when searching for rare species.

Virginia pine (Pinus viriginiana) on bluff tops | South Cumberland State Park

Virginia pine (Pinus viriginiana) on bluff tops | South Cumberland State Park, Tennessee.

During my searches, I gave a lot of attention to one particular tree at the far end of the bluff—though it was alive and not showing any outward signs of distress, there was just something about it that made me think, “that’s a buprestid tree.” I don’t know if it was the sparsely limbed crown, the relatively smooth trunk with one side fully exposed to the sun, or just its lonely position at the edge of the bluff away from other trees (regretfully, I did not photograph the tree). At any rate, I checked it over every time I wandered down to that end of the bluff. During one of my inspections, I mentioned to Josh that I thought this tree looked good for buprestids, and as I did my eyes suddenly noticed a large individual in the genus Buprestis sitting on the trunk right in front of me. I grabbed it and yelled out to Josh what I’d found—I recognized it as a member of the subgenus Cypriacis but wasn’t sure about the species. Josh came over to take a look and immediately recognized it as B. strata. He mentioned that this was one of several other species besides C. orono that he and Nadeer have found before at this site. I told Josh that this was yet another species I’d never collected before (although I do have a specimen in my collection received in trade). The photos below were taken later that evening in the safety of the studio with the beetle on a piece of Virginia pine bark. This species is recognizable as a member of the subgenus Cypriacis by the elytra with alternate intervals depressed and heavily punctate, giving the beetle a strongly ribbed appearance—there are a few other species in this subgenus in northern and western North America.

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

This find fueled another hour or so of continued searching of the pines, now not only for C. orono, but also for B. striata. As we continued to search, I queried Josh about the other species he had collected here. One that he mentioned that got my attention was Buprestis salisburyensis. I mentioned that not only had I never collected that species either, but that I’d never even seen it. Eventually I asked him what it looked like, and he went on to describe what sounded to me like an incredibly beautiful species—brilliant, metallic blue-green with bright red around the edges of the elytra. As he described the species, I began walking back towards the tree, and immediately I saw one sitting on the rock at the base of the tree. I yelled out, “There’s one!”, crept up slowly, and clamped my net over it (all of which was probably unnecessary—most Buprestis species are rather clumsy and easy to capture, unlike the comparatively zippy Chrysobothris). The photos shown here, like those of B. striata, were also taken later that evening indoors—even though I had found the beetle sitting on the rocks at the base of the tree I thought it would look more natural on Virginia pine bark. I also photographed the beetle on a needle clump, as this and other members of the subgenus Stereosa (recognizable by the large punctures of the elytra) have been beaten from needles of young. healthy pines (Helfer 1941). This makes perfect sense to me, given their coloration which could actually serve a cryptic function.

Buprestis (Stereosa) salisburyensis | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis | South Cumberland State Park, Tennessee.

I mentioned a third species that I collected for the first time that day—after finishing at South Cumberland State Park, Josh took me to a spot where he had collected North America’s only coraebine buprestid, Eupristocerus cogitans. This species breeds in alder, and there was a sickly clump of alder trees next to a small lake. I looked at the tree, stuck my beating sheet under a branch and gave it a whack—there sat two individuals! I moved the sheet under another branch, gave it a whack, and there sat two more individuals! In my excitement of having collected this species for the first time (and my zeal to get even more), I completely forgot about making sure the vial I placed them in was not charged with ethyl acetate so that I could take photos later on. When I finally realized my mistake it was too late—the specimens were dead. I suppose I could have placed one on a branch and photographed it anyway, but with live individuals of Chrysobothris orono, Buprestis striata, and B. salisburyensis already in queue for photographs I opted to hope for a second chance someday.

REFERENCE:

Helfer, J. R. 1941. A revision of the genus Buprestis of North America north of Mexico (Coleoptera, Buprestidae). Entomologica Americana 21(3):123–199.

© Ted C. MacRae 2014

Chrysobothris orono in Tennessee

/ Ted C. MacRae / 10 Comments
Virginia pine on bluff tops | South Cumberland State Park, Tennessee

Virginia pine on bluff tops | South Cumberland State Park, Tennessee

Some years ago, I sent a list of 47 species of Buprestidae for which I had records of occurrence in Tennessee to Joshua Basham, who had recently become interested in the family and wanted to develop a checklist for the state. One of the species on that list—Chrysobothris orono Frost, 1920—caught Josh’s attention, not only because it is a beautiful and very uncommonly encountered species, but also because of the dubious nature of the lone Tennessee record for the species. Knull (1930) recorded a specimen in his collection from ‘‘Fresno Co., Tennessee’’ without further information. However, there is no such county in the state (or any other state in the country outside of California), and Josh was also unaware of any town by that or a similar name in the state.

Chrysobothris orono Frost, 1920 | South Cumberland State Park, Tennessee

Chrysobothris orono Frost, 1920 | South Cumberland State Park, Tennessee

A few years later, in 2012, Josh and colleague Nadeer Youssef succeeded in finding C. orono in Tennessee at South Cumberland State Park—just one hour east of their facility in McMinnville! They collected nearly two dozen specimens from late May to late July during that and the following year, all associated with exposed roots of Virginia pine (Pinus virginiana) growing on the edges of high bluff tops. This was a significant find because it confirmed the occurrence of the species in the state, which heretofore had only been recorded from a handful of states/provinces along the eastern seaboard and around the Great Lakes. Moreover, they found a carcass of an individual that died while emerging from its host, confirming Virginia pine as a larval host. Until then, red pine (P. resinosa) was the only confirmed larval host for the species (Wilson 1969) [Paiero et al. (2012) did also record the species as reared from jack pine, P. banksiana; however, I am unaware of the source of that record]. Both the confirmed state and larval host records were documented in our recent joint paper (MacRae & Basham 2013).

Rarely collected, this species has been reared from several species of pine.

Rarely collected, this species has been reared from several species of pine.

I was especially interested in news of this species being collected in Tennessee, as it was a species I myself had never encountered (having in my collection only a single specimen received in trade). Josh and I had been looking for an opportunity to get out into the field together, so in late May this year I met up with him and Nadeer in McMinnville to look first for Chrysobothris seminole at the type locality in Georgia and then C. orono at South Cumberland State Park in Tennessee. We were a little concerned about the timing of the trip, considering this year’s late spring and that our visit would be on the early side of the dates of occurrence recorded at the site. Nevertheless, Lady Luck shone down upon us, and within minutes of arriving at the site we saw the first beetle. Josh saw it just as it flew from an exposed root and watched it land on a nearby rock. I had hoped to get in situ field photographs of the species, but protocol for the first encounter with any rare, flighty species is to collect the specimen live as a studio backup in the event that I am unsuccessful with field photographs. Josh graciously allowed me to collect and keep this first specimen, and Nadeer saw another individual which he netted in flight shortly afterwards.

Chrysobothris orono was only one of several very cool buprestid species collected on this day...

Chrysobothris orono was only one of several very cool buprestid species collected on this day…

Alas, these would be the only individuals we would see, so I would have to be content with the photos shown here that were taken later that night on a Virginia pine root with an emergence hole.¹ In addition to C. dentipes (see subtext below), we also encountered two other very nice species of Buprestidae at the site. However, discussion and photos of these will be saved for a future post…

¹ It is possible that the emergence hole is that of Chrysobothris dentipes (Germar, 1824), which we also found associated with exposed pine roots at this locality. However, the size of the hole does seem to match the slightly larger C. orono.

The author catches his first ever Chrysobothris orono (photo by Joshua Basham).

The author catching Chrysobothris orono (photo by Joshua Basham).

REFERENCES:

Knull, J. N. 1934. Notes on Coleoptera, No. 4. Entomological News 45(10):207–212 [BioStor].

MacRae, T. C. & J. P. Basham. 2013. Distributional, biological, and nomenclatural notes on Buprestidae (Coleoptera) occurring in the U.S. and Canada. The Pan-Pacific Entomologist 89(3):125–142 [pdf].

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. Canadian Food Inspection Agency. 411 pp. [pdf].

Wilson, L. F. 1969. Life history, habits and damage of Chrysobothris orono (Col., Buprestidae) on red pine in Michigan. The Canadian Entomologist 101(3):291–298 [abstract].

© Ted C. MacRae 2014

Great Smoky Mountains National Park

/ Ted C. MacRae / 5 Comments

Is there any question why these are called the Smoky Mountains?

Last week I attended the Entomological Society of America (ESA) meetings in Knoxville, Tennessee. It was my first ESA attendance in more than ten years, so I took full advantage of the opportunity by speaking at the insect macrophotography symposium, presenting a poster on my soybean insect research, and enjoying face-to-face conversations with an extraordinary number of colleagues—some of whom I had not seen since my last ESA meeting and many more for which this was my first opportunity to meet them in person. I admit to having grown a little complacent in recent years about the importance of regular personal contact in cultivating these relationships—my attendance at this year’s ESA reminded me of that fact, and I’ve renewed my commitment to make ESA attendance a priority in the coming years.

Of course, no meeting should be all work and no play, and for me the chance to sample the local natural or cultural history is an added benefit of meeting attendance. This year’s destination for such was a no-brainer—located less than an hour’s drive from Knoxville, Great Smoky Mountains National Park is the largest federally protected area east of the Mississippi River. Straddling some of the highest peaks of one of the world’s oldest mountain ranges, the park has been designated an International Biosphere Reserve by the United Nations due to its rich biota.

One afternoon is not nearly enough time to even scratch the surface of the park’s 800 square miles, but it’s enough to get a taste of the diverse habitats they encompass and whet the appetite for further exploration. Highly recommended for those short on time is Clingman’s Dome—the park’s highest point at 6,643 ft. An observation tower allows spectacular vistas (provided the day has good visibility) of the surrounding mountains and the evergreen forests that cloak them. Unfortunately, the view has been marred in recent years by the accidental introduction of an exotic woolly adelgid (a relative of aphids) from Europe and its subsequent establishment on the forest’s Frazier firs. Dead trunks rise from the forest like tombstones—ghostly reminders of what has been lost. The starkness of the high elevation forest contrasts with the lush mixed hemlock forest that dominates the park’s lower elevations, and the 2.4-mile Alum Creek Trail provides an intimate experience with this rich forest and its thick understory of native rhododendron. I hope the following slide show imparts some essence of the experience, and larger versions of each photo can be seen by clicking on the thumbnails in the gallery that follows.

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Copyright © Ted C. MacRae 2012

Life at 8X—Bandedwinged Whitefly

/ Ted C. MacRae / 10 Comments

Trialeurodes abutiloneus (bandedwinged whitefly) | Obion Co., Tennessee

The world of minute insects can seem strange and even bizarre when compared to our relatively giant perspective. To the unaided human eye, this bandedwinged whitefly (Trialeurodes abutiloneus), measuring only 1 mm in length, looks like nothing more than a fleck of dandruff. Through a Canon MP-E 65mm 1–5X macro lens with 68 mm of extension tube (resulting in 8X magnification), however, we see an almost moth-like insect with a decidedly adorable “face” negotiating the “trichome forest” of a soybean leaf under-side.

A more conventional 2X view of a whitefly infestation on the underside of a leaf

Whiteflies (order Hemiptera, family Aleyrodidae) are tiny insects (more related to aphids than true flies) that colonize a variety of host plants, often building to extraordinary numbers and densities while sucking juices from the leaves. The bandwinged whiteflies in these photos were seen in a soybean field in northwestern Tennessee this summer and can be easily identified as this species due to the transverse, zig-zag bands on the forewings (Malumphy et al. 2010). In the photo above numerous eggs can also be seen distributed over the leaf surface—a sign that this population is about to explode given the numbers of eggs present.

Zooming in to 8X allows the zig-zag wing pattern to be seen easily.

Whiteflies are an occasional pest of soybean in the U.S., but yield reduction has been documented only in the southeastern U.S. by another species, Bemisia tabaci (sweet potato whitefly). Whiteflies are also occasionally seen on soybeans in the Midwest by B. tabaci or yet another species, Trialeurodes vaporarium (greenhouse whitefly); however, yield impacts in this area are rare. Trialeurodes abutiloneus is occasionally reported from soybean, but this species is actually more commonly encountered on sweet potato and malvaceous crops such as cotton and hibiscus (Clower et al. 1973). There was a lot of cotton growing in the area of this soybean field, so perhaps this infestation was a result of spillover from that crop.

Piercing/sucking mouthparts are inserted into the leaf for feeding.

“Adorable” and “cute” are not words that I’ve ever associated with whiteflies, but these ultra-closeup photographs give them a personality that I’ve not seen before. For an even more astounding view of the face of a greenhouse whitefly, see this incredible 16X photograph by Huub de Waard. Taken with the same lens as these—though I suspect with a 2X converter rather than extension tubes, it shows an amazing level of sharpness compared to the admittedly soft photos in this post. The larger aperture used (f/6.3) may also be a better choice than the small f/13 aperture I used in an attempt to preserve as much depth of field as possible but with which diffraction is likely significantly greater. Stay tuned as I do some more testing…

A cute couple!

REFERENCE:

Clower, D. F. & C. M. Watve. 1973. The bandedwinged whitefly as a pest of cotton, pp. 90–91. Proceedings of Beltwide Cotton Production and Research Conference, 11–12 January, Phoenix, Arizona. Cotton Council of America, Memphis, TN.

Malumphy, C., A. MacLeod & D. Eyre. 2010. Banded-winged whitefly Trialeurodes abutiloneus. Plant Pest Factsheet, The Food and Environment Research Agency (Fera), 4 pp.

Copyright © Ted C. MacRae 2012