North America’s most…

One of North America’s rarer longhorned beetles

/ Ted C. MacRae / 5 Comments

Here are dorsal and lateral views of the only specimen I’ve ever collected of Neoclytus approximatus—one of North America’s most uncommonly encountered longhorned beetles. I collected it on dead Pinus echinata in southeastern Missouri (Carter Co.) way back on June 7, 1987 (just over 34 years ago!), but I believe that is only an incidental record and not a larval host for the species considering that the species has been recorded from primarily the U.S. Great Plains (North Dakota south to Texas, east to Iowa and Missouri, and west to Colorado)—a region mostly devoid of native pines.

Neoclytus approximatus (dorsal view).

What it does breed in remains a mystery. I’ve seen a number of specimens collected in the city of St. Louis, Missouri in the 1930s with U.S.D.A. eugenol-baited Japanese beetle trap, although my own efforts with Japanese beetle traps in St. Louis during the 1980s turned up no specimens. Another Missouri specimen bore a label saying “Monarda” (a genus of flowering plants called “bee balms”)—perhaps referring to the flower of the plant (MacRae 1994). This latter record may suggest the species breeds in herbaceous plants rather than woody plants—which some longhorned beetles are known to do, and its apparent distribution across the Great Plains makes this idea even more tenable.

Neoclytus approximatus (lateral view).

Van Pelt (2007) provides the only other clue to host for the species, citing it “on shrubs” in Big Bend National Park. Until somebody figures out the host for this species, it is liable to remain one of the most elusive species of North American Cerambycidae.

Literature Cited

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

Van Pelt, A. F. (ed.). 2007. Inventory of insects of Big Bend National Park, Texas. Report to Big Bend National Park, 204 pp.

© Ted C. MacRae 2021

North America’s most “extreme” jewel beetle

/ Ted C. MacRae / 16 Comments

When Chuck Bellamy passed away two years ago, he left behind a remarkable legacy of study on the family Buprestidae (jewel beetles) that includes not only his insect collection—surely one of the best in the world in terms of representation of genera and species in the family—but also his extensive library of primary literature. Both of these assets, built over a period of decades, are now housed in the California State Collection of Arthropods at the CDFA Plant Pest Diagnostics Laboratory in Sacramento, California. Chuck, however, was not just a jewel beetle collector and taxonomist—he was also a skilled photographer, focusing (pun intended) largely, though not exclusively, on his beloved jewel beetles. Digital cameras were still far in the future when Chuck began photographing these beetles, and as a result the bulk of his photographic legacy exists in the form of 35mm slides. I was the fortunate recipient of his slide collection, numbering in the thousands, and have been slowly scanning his slides into digital format with the goal to eventually make them available to the larger community of buprestid workers. Some of his best photos were published in a memorial issue of The Coleopterists Bulletin (2014, volume 68, number 1), and I featured a few additional photos in this post shortly before the publication of that issue. There remain slides, however, of many additional species, a large number of which surely represent the only field photographs of live adults. As I convert his slides to digital format, I hope to share some of the more interesting here.

For the first of these featured species, I can think of no better one than Lepismadora algodones. This tiny little jewel beetle is the only representative of the genus, which was not even known until 1986 when it was discovered by Mimi & Rob Velten in the Algodones Sand Hills of southeastern California. The species and genus were described the following year (Velten & Bellamy 1987), making Lepismadora the most recently discovered new genus of jewel beetle in the U.S. The recentness of its discovery is remarkable, since southern California in general and the Algodones Sand Dunes in particular were thought to have been relatively well collected at the time of the beetle’s discovery. Also remarkable is the distant relationship of this monotypic genus to any other North American species; its closest known relative being the genus Eudiadora—known only from Argentina (Bellamy 1991).

Lepismadora algodones

Lepismadora algodones Velten, in Velten & Bellamy, 1987 (Coleoptera: Buprestidae)

Even more remarkable, however, are its highly localized distribution and extreme habitat. The entire type series (one male holotype and 159 paratypes) and all individuals collected since its description have been found only in a single old canal on the west side of the Algodones dunes. Summer temperatures in the dunes routinely reach in excess of 110°F and are even higher in the depressed canal where the beetles are found. Astoundingly, the adults are active only during the hottest hours of the day (ca. 10 a.m. to 2 p.m.), during which time they can be found on the flowers and foliage of fanleaf crinklemat, Tiquilia plicata (Boraginaceae). The reason for the beetle’s highly restricted distribution is a mystery, as the plant on which the beetles are found is rather widespread across the southwestern U.S. and northwestern Mexico. A final mystery is the still unknown larval host plant—it could be T. plicata, but it could just as likely be something completely different.

Algodones Dunes

Old canal on the west side of Algodones Sand Hills, type locality of Lepismadora algodones.

I moved to California a few years after the species was described and, of course, soon set out to find it for myself. I had driven to southern California from my home in Sacramento to meet the late Gayle Nelson (another important mentor of mine), who told me where to find the beetle and what the host plant looked like but also warned me about the extreme heat I would encounter. His advice was to hike the canal until I had half a bottle of water, then turn around and hike back. Mindful of his advice, I arrived at the dunes the next day around mid-morning, filled my water bottle and hydrated myself as much as I could, and climbed down into the canal. The heat was overpowering—more so down in the canal and far beyond anything I had ever experienced to that point, and after quickly recognizing the host plants I began tapping their tiny, prostrate branches over my beating sheet and looking for the beetles. I went as far as I could down the canal, perhaps 200 yards, before I had to turn around, but I had not yet seen any beetles and was starting to lose hope. I continued to tap host plants on the way back, though by then not really expecting to see anything. About halfway back I saw something laying on the ground a short distance ahead. As I approached I saw it was a small plastic vial with a white cap, and when I picked it up I saw inside a dried out T. plicata twig and a dead adult beetle—unmistakably L. algodones! While excited to have found the species, it was at the same time a bit unsatisfying for the specimen to be one that somebody else had collected before me and then lost (for all I know, it could have been Chuck Bellamy, considering that the beetle was apparently intended to be kept alive, possibly for photography!). I slipped the vial into my pocket, started tapping branches again, and found three additional adults in the immediate vicinity of where I had found the vial (and doing much to soothe my dissatisfaction with the first specimen). Those would be the only specimens that I would find that day, though I would succeed in finding another individual on a subsequent visit two years later.

REFERENCES:

Bellamy, C. L. 1991. A revision of the genus Eudiadora Obenberger (Coleoptera: Buprestidae). Proceedings of the Entomological Society of Washington 93(2):409-419 [Biodiversity Heritage Library].

Velten, R. K. & C. L. Bellamy. 1987. A new genus and species of Coroebini Bedel from southern California with a discussion of its relationships in the tribe (Coleoptera, Buprestidae). The Coleopterists Bulletin 41(1):185–192 [pdf].

© Ted C. MacRae 2015

Multiple Megarhyssa males

/ Ted C. MacRae / 9 Comments

Today while hiking at Hilda Young Conservation Area (north-central Jefferson County, Missouri), I encountered a declining sugar maple (Acer saccharum) with lots of woodboring insect holes in the trunk. As I approached I noticed numerous giant ichneumon wasps in the genus Megarhyssa flying about the trunk and resting on its surface. Giant ichneumons belong to the family Ichneumonidae and are, as the name suggests, the largest members of the family in North America. Interestingly, all of the wasps that I initially saw were males. I have never seen male giant ichneumon wasps before, and certainly not in such numbers, so this was quite exciting. We have two species of giant ichneumons here in Missouri—M. atrata and M. macrurus, the females of which I have seen only rarely, but I couldn’t immediately decide which of these two species the males represented. I looked up higher on the trunk, and there I saw a female M. macrurus in the act of oviposition, so I decided that the males must also represent this species. However, one of the males was smaller and differently colored than the others, having more brown than black on the body and the wings clear with a well developed spot on the costal margin. The other males were noticeably larger and had more black than brown on the body and the wings smoky with only a narrow spot on the costal margin. After a little bit of digging, I know believe that the smaller male is also M. macrurus—the same species as the ovipositing female, while the larger males all represent the larger species M. atrata.

Megarhyssa macrurus (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

Megarhyssa macrurus (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

Megarhyssa atrata (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

Megarhyssa atrata (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

As I watched the males that had landed on the trunk of the tree, I observed both the M. macrurus male and one of the M. atrata males to bend their abdomen forward beneath their body rub the tip of the abdomen against the bark, a behavior called “tergal stroking”, and at times inserted the tip of the abdomen into cracks in the bark in an almost prehensile-looking manner. These behaviors belong to a suite of behaviors exhibited by male Megarhyssa aggregations. Previously thought to be function in early insemination of as-yet-unemerged females, the precise function of these behaviors remains unknown but seems somehow related to enabling sex discrimination of emerging wasps and/or increasing the rate at which virgin females are encountered (Matthews et al. 1979).

All species of Megarhyssa parasitize the woodboring larvae of Pigeon horntails (Tremex columba) (order Hymenoptera, family Siricidae), which the females reach by inserting their long, thin ovipositor deep into the wood where the horntail larvae live. Multiple species of giant ichneumons occurring in the same area at the same time and utilizing the same resource seems to violate a basic ecological concept; the competitive exclusion principle, which states that two species competing for the same resource cannot coexist at constant population values because one species will always eventually outcompete the other. In the case of Megarhyssa, it seems that size differences between the species allow them to share a common resource (horntail larvae), as females of the larger M. atrata have longer ovipositors than the smaller M. macrurus, thus allowing them to penetrate deeper into the wood to parasitize horntail larvae that M. macrurus females cannot reach. By the same token, M. macrurus females tend to parasitize horntail larvae tunnel at shallower depths and that tend not to be utilized by M. atrata females.

REFERENCE:

Matthews, R. W., J. R. Matthews & O. Crankshaw. 1979. Aggregation in male parasitic wasps of the genus Megarhyssa: I. Sexual discrimination, tergal stroking behavior, and description of associated anal structures behavior. The Florida Entomologist 62(1):3–8 [pdf].

© Ted C. MacRae 2015

What’s black and white and red all over?

/ Ted C. MacRae / 19 Comments

Last September, labmate and fellow insect collecting enthusiast Stephen Penn and I visited the dolomite glades of the White River Hills in extreme southwestern Missouri. Our main quarry was tiger beetles, specifically a disjunct population of the large and impressive Prairie Tiger Beetle (Cicindelidia obsoleta vulturina) that lives only on the glades in this area and adjacent Arkansas. I was hoping to find additional localities for the beetles in the more western parts of the region where it’s precise distribution in Missouri is less well known. First, however, I wanted to make sure the beetle was out, so we started at the westernmost of its known locations—Chute Ridge Glade at Roaring River State Park. As we picked our way through dry-mesic woodland bordering the more open glades, a large, dead chinquapin oak (Quercus muehlenbergii) with sloughing bark caught my eye. One never knows what might be encountered under bark, regardless of the season, and as I pulled away the very first slab of bark I was rewarded with the sight of what must be North America’s most beautiful assassin bug, Microtomus purcis.

Microtomus purcis

Microtomus purcis (Drury, 1782) | Barry Co., Missouri

Sometimes called the “bark assassin bug”, this species is not quite as large as the better known “wheel bug” (Arilus cristatus) but makes up this by its spectacular coloration—black with the base of the wings prominently marked creamy-white and parts of the abdomen and hind legs bright red. One would think such a conspicuously  marked assassin bug with a bite powerfully painful enough to back up its apparent warning coloration could brazenly venture out during the day with little to fear. To the contrary, this species seems best known for its habit of hiding under bark during the day and venturing out only at night, during which time it is sometimes attracted to lights (Slater & Baranowski 1978, Eaton & Kaufman 2007). A majority of BugGuide photos of the species also mention finding them under bark or apparently attracted to lights.¹

¹ I was especially amused by this particular photo for which the contributor states, “While holding it, the bug pierced my finger nail with its proboscis. The pain was searing and I have a small blood stain under the nail.” I’ll admit it—I, too, learned firsthand how painful the bite of an assassin bug can be when I picked one up, in my case Melanolestes picipes, with plans to include it in my Entomology 101 collection.

Sunset on the glade

Sunset on the glade | Pilot Knob Conservation Area, Stone Co., Missouri

I, in fact, have only seen this species once before—also in Missouri and again under bark, although that time was during the winter, thus causing me to think this was its overwintering habit. I placed the individual in a glass vial and brought it indoors to “revive” it, but to my disappointment when I checked on it a few days later it was dead. Froeschner (1944) reported this species (under its older name, Hammacerus purcis) was “not uncommon” in Missouri, though apparently confined to the Ozark Highlands south of the Missouri River. Adult records in Missouri extended from September to March, with small nymphs being found during November and December, but BugGuide records include summer months as well. If I want to see this species more than twice in 30 years, I supposed I am going to have to spend more time peeling bark, or checking lights.

REFERENCES:

Eaton, E. R. & K. Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Harcourt, New York, 391 pp. [Amazon preview].

Froeschner, R. C. 1944. Contribution to a synopsis of the Hemiptera of Missouri, Pt. III. Lygaeidae, Pyrrhocoridae, Piesmidae, Tingidae, Enicocephalidae, Phymatidae, Ploiariidae, Reduviidae, Nabidae. The American Midland Naturalist 31(3):638–683 [JSTOR preview].

Slater, J. A. & R. M. Baranowski. 1978. How to Know the True Bugs. The Pictured Key Nature Series, William C. Brown Company Publishers, Dubuque, Iowa, x + 256 pp. [Amazon description].

© Ted C. MacRae 2015

North America’s Most Beautiful Agrilus Jewel Beetle

/ Ted C. MacRae / 6 Comments

For the past few years I’ve spent the summers traveling once a month or so from my home near St. Louis to research plots in western Tennessee. I enjoy these trips immensely—not only are my research and the colleagues that I spend time with fun, but I also get to keep an eye on the progression of the season in one of Missouri’s most interesting (and threatened) natural communities: the southeastern lowlands. Spring sees the emergence of an unusual population of the Festive Tiger Beetle (Cicindela scutellaris) in the area’s critically imperiled sand prairies; summer harks the appearance of the diminutive and almost-impossible-to-see Ant-like Tiger Beetle (Cylindera cursitans) in the ribbons of wet bottomland forest that line the Mississippi River; autumn is graced by the sight of stunningly beautiful amorpha borers (Megacyllene decora) in wet areas hosting mixed stands of false indigo (Amorpha fruticosa) and goldenrod (Solidago spp.); and all season long a variety of seldom-seen insects (e.g., longhorned beetles that look like stag beetles) are attracted to ultraviolet lights set up in the area’s increasingly scarce natural habitats.

Hairy mallow (Hibiscus lasiocarpus), host for Agrilus concinnus

Hairy mallow (Hibiscus lasiocarpus), host for Agrilus concinnus

Another phenological event that I look forward to in the southeastern lowlands is the blooming period of hairy mallow (Hibiscus lasiocarpus). Starting in July and reaching its peak in early to mid-August, the enormous white (and sometimes pink) flowers explode across the landscape at a time when precious few other flowers can be found, conspicuously flagging any ground where water tends to stand. It is not the flowers themselves, however, that pique my interest, but rather a beautiful (and, until recently, rare) jewel beetle (family Buprestidae)—Agrilus concinnus—that becomes active on the plants while they are in flower. In fact, of the nearly 200 species belonging to the genus in North America, I consider A. concinnus to be perhaps the most beautiful!

Agrilus concinnus | Stoddard Co., Missouri

Agrilus concinnus | Stoddard Co., Missouri

I first saw this species in Missouri’s southeastern lowlands nearly 30 years ago. At that time, I didn’t know that the mating pair that I had found on low vegetation represented a species considered to be one of the rarest of the genus in North America (having been recorded only from Florida, Georgia, Illinois, and Texas and not yet known from Missouri) and whose host plant and biology were completely unknown. Over the course of several years following this first find, fellow buprestophile Gayle Nelson (now deceased) and I were able to document the occurrence of this species also in Kansas (MacRae & Nelson 2003) and confirm its association with plants in the genus Hibiscus (MacRae 2006). We also determined that adults of this species exhibited an unusually late seasonal occurrence, peaking in late July and early August, compared to the spring adult activity period of most other eastern North American species in the genus. As a result of these efforts, one of North America’s rarest and least known jewel beetles was no longer regarded as either. A more detailed summary of my experiences with this beetle can be found in a newsletter article that I wrote a while back (MacRae 2004).

Hibiscus lasiocarpus

Plants in peak bloom signals the adult activity period of the beetle.

Of course, those were the days before I began photographing insects, so despite the abundance with which I have seen this species in past years, I still lacked photographs of it. I first made an effort to photograph adults two years ago while on one of my research plot trips, but 2012 was characterized by a severe drought in the central U.S.—precious few potential host plants were found at the locality where I first collected these beetles, and those that were present were severely stunted and in poor shape due to the drought. Conditions were much more favorable last year (2013), but again no beetles were seen during an early August visit. This past season was again favorable for growth of the host plants, and though my visit during early August again looked like it was not going to pay off, I eventually scared up an adult and watched it as it flew to another plant. I would see four adults on the day—not a lot, but enough to make sure that I got photographs showing how spectacularly beautiful they are!

Agrilus concinnus

Adults perch, mate, and feed on the upper leaf surfaces.

REFERENCES:

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 [pdf].

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 [pdf].

MacRae, T. C. & 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 [pdf].

© Ted C. MacRae 2014

North America’s largest scarab beetle

/ Ted C. MacRae / 28 Comments

Dynastes tityus male - USA: Missouri, Jefferson Co., DeSoto

As one of North America’s largest, most written about, and most photographed beetles, Dynastes tityus (eastern Hercules beetle) hardly needs an introduction.  I photographed this male specimen from my collection back in December while testing my DIY diffuser for the MT-24EX twin flash and 100mm macro lens.  It’s a good test subject for such – its glossy exoskeleton may be beauty to the eye but is the bane of flash photographers, and its nearly 60mm of length demand a huge subject-to-lens distance that gives even the largest lens-mounted flash a small apparent size.  Nevertheless, the diffuser did a pretty good job of creating even illumination and preventing harsh specular highlights, giving almost the effect of an indirect strobe in a white box.

Dense setae adorn the underside of the thoracic horn of the male.

I hadn’t really noticed until I took the photos the dense adornment of setae (hairs) on the underside of the thoracic horn.  While setae in insects most often perform a tactile function, the density and placement on the horns of the males of these beetles makes me wonder if they might serve more of a display function.

Despite the overwhelming popularity of this beetle amongst hobbyist breeders and its widespread occurrence across the eastern United States (and the internet), it is not one that I have encountered with much frequency myself.  I suspect this is due to the position of Missouri near its western limit of distribution – likely a function of the species’ preference for moist treehole cavities with rotting wood in which the larvae can develop.  This particular specimen was given to me many years ago by a nursery grower in Jefferson Co. during my first job out of graduate school – before I’d ever found one myself, but since then I’ve encountered perhaps half a dozen or so at blacklights in mesic forests across the eastern Ozark Highlands.  Most recently (last summer) I found a female sitting on my driveway, apparently attracted to the mercury vapor lamp above the garage that I leave on occasionally during the months of June and July just for such purpose.

Copyright © Ted C. MacRae 2011

North America’s largest stag beetle

/ Ted C. MacRae / 30 Comments

 

Here is the full-sized photo that provided the image for yesterday’s Super Crop Challenge #3.  The insect in the photo is, of course, a fine example of a male Lucanus elaphus – the giant stag beetle (family Lucanidae).  This striking insect is easily among North America’s most distinctive and recognizable species by virtue of the enormously super-sized mandibles sported by the males.  Its fearsome appearance belies the true nature of this harmless beetle, which spends its days feeding on sap that flows from wounds on the trunks and roots of trees.  Males use their massive mandibles in combat with other males, not for “biting,” but rather as tools to pry and lift their adversaries before dropping them to the ground.  Some marvelous photos of this behavior in a related European species can be seen at Stag Beetles Lucanus cervus Mating Behaviour.

I collected this specimen many years ago at an ultraviolet light (“blacklight”) that I had setup in the pine/oak forests at Pinewoods Lake, Carter Co., in the southeastern Ozarks – one of my favorite 1980’s beetle collecting spots.  This was in my early days of studying beetles, during which time I was actively collecting material as part of my statewide surveys for the families Buprestidae (MacRae 1991) and Cerambycidae (MacRae 1994).  Lucanus elaphus is not a commonly encountered species, especially in the western reaches of its distribution here in Missouri, and I’ll never forget my rabid excitement when I encountered this fine major male at my blacklight sheet.  For many years afterward it remained the only individual that I had ever encountered, until a few years ago when I came across a group of two males and one female feeding on a sap flow in a wet bottomland forest along the Mississippi River in the lowlands of southeastern Missouri.  I encountered another male the following year at a nearby location “rafting” on debris in floodwaters from the nearby river, and two weeks later at that same site I picked up several males and females in a fermenting bait trap.¹  Like most “uncommon” species with broad distribution across the eastern U.S., I suspect that its apparent rarity is an artifact due to habits that make it infrequently encountered rather than being truely scarce.

¹ I have used fermenting bait traps to collect a wide variety of beetles, but especially longhorned beetles.  My recipe is based on that described by Champlain and Knull (1932) – bring 12 oz. dark molasses and 12 oz. beer up to 1 gal. with water, mix well and add a packet of dry baker’s yeast to get the fermentation started.  Hang a 1/2-gallon milk jug with big holes cut in the sides in a tree along the edge of a woods and add ~1 quart of fresh liquid.  It generally takes 2-3 days for the liquid to really start fermenting and become attractive, and it will remain so for about another week or so.  Check traps every 2-3 days by pouring the liquid through a kitchen strainer into another container – reuse or replace as necesssary. Place the collected specimens in vials of water to wash off the molasses residues, and either pin immediately afterward or transfer to 70% ethanol for longer term storage.  Some of the more desireable species I’ve collected in this manner, besides L. elaphus, are Plinthocoelium suaveolens, Purpuricenus axillaris, P. humeralis, P. paraxillaris, Stenocorus cylindricollis, S. shaumii, Sarosesthes fulminans, Stenelytrana emarginata [= Leptura emarginata], and S. gigas [= Leptura gigas].


Congratulations to Ben Coulter and Janet Creamer, both of whom correctly identified the species and most of the mouthparts.  Each earned 14 pts and, thus, tied for the win, while JasonC. earned 5 pts. to take the final podium spot.  The pointed structure is the labrum (its shape distinguishing it from other North American species of the genus), and it is flanked on each side by the fuzzy yellow galeae (derived from the maxillae) and the labial palps.  Nobody correctly named the galeae, which seem to be greatly elongated and hairy in stag beetles as a function of their sap feeding behavior.  A portion of the left maxillary palpus can also be seen in the corner of the photograph, but nobody scored those points either.  Brady Richards just missed the podium, but his witty reference to Gene Shalit (if not immediately picked up on by me) earns him an honorable mention.

With points being formally awarded now beginning with the previous competition (ID Challenge #1), I’ll start keeping an overall leaders board, and with wins in both competitions Ben takes a commanding lead in the overalls with 23 pts, followed by Janet Creamer at 14 pts and TGIQ at 8 pts.  I guess I should start thinking of some sort of tangible prize for winners periodically – suggestions welcome.  Stay tuned for another issue of Super Crop Challenge or ID Challenge in the near future.

REFERENCES:

Champlain, A. B. and J. N. Knull.  1932. Fermenting bait traps for trapping Elateridae and Cerambycidae (Coleop.).  Entomological News 43(10):253–257.

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

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

Copyright © Ted C. MacRae 2010

North America’s most beautiful tiger beetle

/ Ted C. MacRae / 18 Comments

Cicindela pulchra pulchra (beautiful tiger beetle) - Fall River Co., South Dakota.

Five years ago this month, I got my first glimpse of North America’s most beautiful tiger – Cicindela pulchra.  This is not just my opinion – its name, given to it by Father-of-North-American-entomology Thomas Say, literally translates to “beautiful tiger beetle.”  Like Amblycheila cylindriformis, it was a species that I longed to see in the field ever since receiving a single specimen from tiger beetle guru Ron Huber.  That specimen came from the Gypsum Hills of Barber Co. in south-central Kansas – a known “hot spot” for the species.  For years I stared at that spectacular specimen as it sat in my cabinet, and in September 2004 Chris Brown and I finally made our first attempt to see it in the field for ourselves.  Unfortunately, we arrived ahead of the fall rains that seem to trigger emergence of this species, and C. pulchra would not be among the few species that we saw on that trip.  I don’t handle defeat very well, so the very next fall I resolved to try again – this time waiting until early October and also enlisting the assistance of local entomologist “Beetle Bill” Smith for access to better sites than what are available along the roadsides.  That trip was a tremendous success and was detailed in one of my Nature Notes articles (MacRae 2006), but Chris, unfortunately, was unable to join me on that second attempt.  He couldn’t join me last year, either, for my search of the species in the nearby Cimarron Gypsum Hills of northwestern Oklahoma.  Good thing, however, as a turn of the weather left me just cold and wet (although I do remain convinced that the species will eventually be found on those red clay slopes that have so far produced such prizes as Cylindera celeripes, Dromochorus pruinina, and Amblycheila cylindriformis).

Matt Brust (L) and Chris Brown (R). Matt discovered this site for Cicindela pulchra in 2009.

Fortunately, while I was getting skunked in Oklahoma, Matt Brust was discovering new populations of the species further north in the southwestern corner of South Dakota.  These discoveries were prompted by the initial discovery of the species on Pierre Shale exposures at a single site near the Black Hills (Larsen and Willis 2008).  The soft, dark gray soils of the Pierre Shales are in distinct contrast to red clay exposures with which the species has been typically associated further south, and by scouting a broader area for similar exposures Matt was able to find the species at six new sites during late summer 2009 (Brust 2010).  He found them associated not only with the Pierre Shale but also the Mowry Shale formation (and suspects they may eventually be found on Belle Fourche Shale formations as well).  When I learned of these discoveries, I decided I just had to see them for myself.  I had enjoyed my Fall 2008 trip to northwestern Nebraska and southwestern South Dakota, and the thought of seeing these beetles while spending time in the field with Matt once again seemed the perfect basis for another trip to the area.  It didn’t take much convincing for Chris to agree, thus, C. pulchra became goal #1 of the 2010 Fall Tiger Beetle Trip™.

Habitat for Cicindela pulchra in Fall River Co., South Dakota. Adults and larval burrows are found in sparsely vegetated gray shale slopes and open flats beneath.

As we drove to the site that Matt had selected for us to explore, I felt nothing but optimism.  The skies were clear and the temperature was already nearing 70°F.  Matt, however, was hedging his bets – “I hope they’re still out, I’ve never seen them this late!”  Still, I wasn’t worried.  We were two weeks earlier in the season than the 2005 Kansas trip, and the weather was simply spectacular – it just had to be a good tiger beetle day!  My optimism was justified, as within minutes of arriving at the site we saw the first individual.  I collected this one alive as a backup for photographs in the studio should that be the last one we saw, but no such contingencies were necessary – we began seeing individual after individual as we trolled across the barren gray slopes.

Adult male Cicindela pulchra taking in the morning sun.

These beetles are simply a marvel to see in the field.  Brilliant dark red with metallic green, blue, and purple borders on the head, thorax, and elytra, this relatively large tiger beetle (certainly among the largest in the genus) can be confused with no other tiger beetle in North America.  Unlike adults of most other species, which exhibit color patterns resembling the texture and hue of the soil substrate on which they occur, C. pulchra adults are obvious and non-cryptic.  It apparently mimics the large, similarly colored velvet ants of the genus Dasymutilla with which they are sympatric – even exhibiting similar behavior when alarmed such as stridulating (creating vibrations by scraping body parts across one another) and giving off defense chemicals (Pearson 1988).  Adults are powerful fliers that can fly long distances when alarmed (Spomer et al. 2008), but in the still relatively cool morning air Chris and I had relatively (emphasis on relatively!) little trouble getting close enough to attempt those coveted field photographs.  This, however, was a double-edged sword – the same cool temperatures that allowed us to get close enough for photographs also caused to the beetles to assume the most non-photogenic poses as they sprawled torpidly on the ground, sometimes hugging it closely in an attempt to conserve heat until incident radiation from the sun warmed them sufficiently to go about the day’s activities.  Once this did happen, we found getting close enough for photographs nearly impossible.  In the 2+ hours that we chased after them, we took many shots but failed to get that “perfect” shot of a brilliant beetle standing tall and alert.

Adult male Cicindela pulchra hugs the ground during the cool morning hours.

Cicindela pulchra is a “spring/fall” species – i.e., sexually immature adults emerge during fall to feed, then return to their burrows to overwinter before emerging again in spring to mate and lay eggs.   Pearson et al. (2006) state the fall period lasts from July to September; however, as I observed in Kansas in 2005 adults can remain active well into October as long as suitable weather prevails.  Larvae hatch shortly after eggs are laid in the spring, but larval burrows can be seen during the entire season since they require 2-3 to complete development.  It was actually the presence of the large larval burrows (see photo below) that alerted Matt to the occurrence of the species at this site.  Several other tiger beetle species are also found here, e.g. C. purpurea (cow path tiger beetle) and C. tranquebarica (oblique-lined tiger beetle); however, these species – and hence their larval burrows – are considerably smaller than C. pulchra.  The only other species of Cicindela in North America that matches C. pulchra in size is C. obsoleta (large grassland tiger beetle), a southwestern species that is not known to range as far north as Nebraska and South Dakota, and the slightly smaller C. formosa (big sand tiger beetle) larval burrow has a distinctive “pitfall trap” with the burrow opening situated horizontally above it (it is also restricted to dry sand rather than clay habitats).  We saw several C. pulchra larval burrows during our visit but no active larvae, and none of my attempts to “fish” them out of their relatively shallow burrows met with success.  I could have tried digging them out, but that is a time-intensive activity, and I decided instead to bring a few live adults back in a terrarium of native soil and see if I could rear the species from egg.

Despite the presence of at least two other tiger beetle species at the site, this can only be that of a 3rd-instar Cicindela pulchra due to its large size.

I had tried persistently during the last hour we were there to get a good field photograph of an active adult beetle standing tall and alert, but the following is the closest I was able to achieve.  Leaving the site without that “perfect” shot was difficult – as Matt put it, we had “pulchra fever”!  Still, there were other tiger beetles – e.g. C. nebraskana (prairie long-lipped tiger beetle) and C. decemnotata (badlands tiger beetle) – that we wanted to find in the limited time we had to explore the region, so I prepared a terrarium for the live adults I was bringing back with me and chalked up our first big success of the trip as we headed towards the shortgrass prairie sitting atop the nearby Nebraska Pine Ridge.

I chased this adult female for some time trying to get a closer photograph, but warming temperatures made this impossible.

In addition to attempting to rear the species,  bringing live adults back with me also gave me more opportunity to photograph them.  In addition to the native crumbly shale soil that I used to fill the terrarium, I placed in it one of the nicely colored, presumably volcanic, rocks that littered the slopes on which the beetles occurred.  The dark color of the rock makes a nice backdrop to really show off the extraordinary colors of this species – especially the bright white labrum and mandibles of the particularly impressive male in the following photograph.  The beetles are all now sound asleep for the winter in a 10°C incubator.  Hopefully, when I move the terrarium back into warm temperatures next spring they will re-emerge, mate, and lay eggs (hmm, photographs of a mating pair would be really nice!).

The all-white labrum and mandibles of this male Cicindela pulchra are displayed nicely in this terrarium photograph.

Photo Details:
Insects: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/16), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers.
Habitat: Canon 50D w/ 17-85mm wide-angle lens (ISO 100, 1/160 sec, f/11), natural light.
Matt and Chris: Canon 50D w/ 17-85mm wide-angle lens (ISO 100, 1/250 sec, f/11), natural light.
All photos w/ typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Brust, M. L.  2010. New distribution records for Cicindela pulchra pulchra Say in South Dakota and notes on habitat use and natural history.  Cicindela 42:1–10.

Larsen, K. J. and H. L. Willis.  2008. Range extension into South Dakota for Cicindela pulchra (Coleoptera: Carabidae).  The Coleopterists Bulletin 62(4):480.

MacRae, T. C. 2006. Beetle bits: The “beautiful tiger beetle”. Nature Notes, Journal of the Webster Groves Nature Study Society 78(4):9–12.

Pearson, D. L.  1988. Biology of tiger beetles.  Annual Review of Entomology 33:123–147.

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.

Spomer, S. M., M. L. Brust, D. C. Backlund and S. Weins.  2008. Tiger Beetles of South Dakota & Nebraska.University of Nebraska, Department of Entomology, Lincoln, 60 pp.

Copyright © Ted C. MacRae 2010