North America’s most recognizable longhorned beetle

One of the more impressive insects that we found during our visit to Sand Hills State Park in south-central Kansas last June was Plectrodera scalator, the cottonwood borer. Large and robust (in fact, the only larger species in the family are the prionid root borers and their kin), their striking checkered pattern of white pubescence on a glossy black body makes them perhaps the most recognizable of all North American longhorned beetles (Linsley & Chemsak 1984). The very robust body of this individual, along with the relatively shorter antennae (only about as long as the body) identify it as a female—males are generally smaller and less robust with the body slightly tapering and the antennae distinctly longer than the body.

Plectrodera scalator

Plectrodera scalator (Fabricius, 1792) | Sand Hills State Park, Kansas

The white coloration on the body of these beetles is not a cuticular pigment (which is rather rare in beetles and is most often associated with species found in white sand habitats, e.g., certain tiger beetles), but instead a result of dense mats of microscopic white setae. The patterns formed by these mats are apparently as unique to each individual as fingerprints are to humans (Yanega 1996), making these beetles at once immediately recognizable as a species yet distinctive as individuals.

Plectrodera scalator

Adults of this species are found most often on cottonwood.

These are said to be common beetles in their range across the eastern two-thirds of the country, especially so in the Great Plains where their favored host, cottonwood (Populus deltoides), is especially abundant. Despite this, I have encountered this species only a handful of times in more than 3o years of searching. I know they’re out there, even in my home state of Missouri where I recorded 154 specimens collected in the state and deposited in various collections (MacRae 1994). It was not until around 2000 that I even saw my first ones (on a cottonwood tree in a homeowner’s yard just across the Mississippi River in Illinois), and in fact this one was actually found by Mary Liz Jameson, who had accompanied us to the field that day. It makes me wonder if their coloration, so strikingly conspicuous when isolated against a clean, blue sky background, might actually afford some type of cryptic protection against the normal backdrop of foliage and branches on which they are normally found—a phenomenon that I call “conspicuous crypsis” and which I have noted for other longhorned beetles (e.g., Acanthocinus nodosus). Perhaps, with this species at least, I have not yet set my search image to notice them.

Plectrodera scalator

Large, robust size and a distinctive checkered pattern of black and white makes these beetles among the most recognizable longhorned beetles in North America.


Linsley, E. G. and J. A. Chemsak. 1984. The Cerambycidae of North America, Part VII, No. 1: Taxonomy and classification of the subfamily Lamiinae, tribes Parmenini through Acanthoderini. University of California Publications in Entomology 102:xi + 1–258. [preview]

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]

Yanega, D. 1996. Field Guide to Northeastern Longhorned Beetles (Coleoptera: Cerambycidae). Illinois Natural History Survey Manual 6, x + 174 pp. [preview]

Crypsis? Mimicry? Crypsimicry?

Continuing with the previous post’s theme on crypsis, here is an interesting insect that I photographed in north-central Oklahoma in late June 2014. I was checking standing and fallen trunks of large, dead eastern cottonwood (Populus deltoides) trees in Woods Co. near the Cimarron River, where just a few days earlier I had found a jewel beetle (family Buprestidae) that had eluded me for more than 30 years—Buprestis confluens. I had found only a single individual and returned to the spot in the hopes of finding more. As I searched the trunk of one particularly large, fallen tree—its trunk still covered with bark, I noticed movement but couldn’t make out right away what I was seeing. A closer look revealed the movement to be from a wasp-like insect, its antennae curiously quivering in a manner that reminded me of an ensign wasp (family Evaniidae). More careful looking, however, revealed the insect to be not a wasp, but a longhorned beetle (family Cerambycidae), which I then recognized to be the species Physocnemum brevilineum.

Physocnemum brevilineum

Physocnemum brevilineum (Say, 1824) on fallen cottonwood (Populus deltoides) | Woods Co., Oklahoma

This beetle is commonly referred to as the elm bark borer, a reference to the larval habit of mining within the bark of living elm trees, but as far as I can tell this beetle is anything but common. Like the Buprestis confluens that I had found a few days earlier, this was a species known to me only by pinned museum specimens (I’m always amazed when a woodboring beetle species is apparently common enough to warrant a common name and is said to reach pest status in some cases, yet eludes my net for decades!). At any rate, my impression based on these pinned specimens and published images was that the species is another of the many longhorned beetles that seem to mimic ants (Cyrtinus, CyrtophorusEudercesMolorchus, and Tilloclytus being among the others). Like many of these other mimics, the species is dark with small amounts of red and bears polished, ivory-colored ridges at mid-elytra to give the illusion of a narrow waist. After seeing a living individual, however, and especially its behavior—in particular the very wasp-like manner in which it moved its antennae, I’m not so sure that ant mimicry alone explains the appearance and behavior of the species.

Physocnemum brevilineum

A lateral view reveals the beetle, but is it trying to mimic an ant, or a wasp, or both?

Of course, there is no reason why it must be ant mimicry or wasp mimicry (or crypsis, for that matter). Evolution has no rule stating that only one survival strategy can be employed at a time, and if, as it seems to me, the beetle is utilizing both crypsis and mimicry—the first to avoid detection and, failing that, the second to give the potential predator pause, then there is no reason why the mimicry portion of its defense couldn’t be modeling both ants and wasps as a way to maximize an overall “nasty hymenopteran” appearance.

© Ted C. MacRae 2015

Redux: Now you see me…

Chalcophora virginiensis

Chalcophora virginiensis (Drury, 1770) | vic. Calico Rock, Arkansas

…now you don’t!

Chalcophora virginiensis

Chalcophora virginiensis (Drury, 1770) | vic. Calico Rock, Arkansas

Chalcophora virginiensis (Drury, 1770) is the largest jewel beetle (family Buprestidae) in eastern North America. This beetle is also known as the “sculptured pine borer”, and its easy to see why—its hyper-sculptured, shiny metallic body glitters like a jewel in the sunlight! This feature is typical of many species in the family and, in fact, is the source of the family’s other common name—metallic wood boring beetles.

Such dramatic sculpturing and coloration makes cabinets of jewel beetle specimens among the most beautiful in any museum, and for those who have only seen these beetles as pinned specimens in cabinets it can be hard to imagine what purpose such appearance serves. In its native habitat, however, on native host plants, the reason becomes clear. Rather than conspicuous and easily seen, such coloration actually helps the beetle to blend in with its environment and become almost invisible. Measuring well over an inch in length and possessing no other way of defending itself by biting, stinging, or even just tasting bad, these beetles would be a more than healthy snack for almost any avian or reptilian predator, and going about their activities during the day right under the noses of all these visually based predators makes finding mates and oviposition sites an even riskier proposition. For them, the best way to beat a visual predator is to become… invisible! The two photos above show just how dramatic a difference the substrate plays in allowing these beetles to practice their disappearing act. Land on the trunk of a dead or dying pine tree, its aged bark flaked and graying, and the sculpturing and coloration are a perfect match. Land, however, on a healthy tree, its resin-filled bark bright and full of color, and it suddenly becomes a sitting duck. It’s in the beetle’s best interest to be good at telling the difference between thrifty and unhealthy trees, which they do by “smelling” volatile chemicals emitted by trees under stress.

Those interested in more information on this species and its close relatives may wish to consult the recent review of the genus in North America by Maier & Ivie (2014) (see my review of this excellent paper here).


Maier, C. A. & M. A. Ivie. 2013. Reevaluation of Chalcophora angulicollis (LeConte) and Chalcophora virginiensis (Drury) with a review and key to the North American species of Chalcophora Dejean (Coleoptera: Buprestidae). The Coleopterists Bulletin 67(4):457–469 [abstract].

© Ted C. MacRae 2015

Amorpha borer on goldenrod

Megacyllene decora (amorpha borer) | Stoddard Co., Missouri

Megacyllene decora (amorpha borer) | Stoddard Co., Missouri

One of my favorite longhorned beetle species is the amorpha borer, Megacyllene decora. Like its close relative, the locust borer—M. robiniae, this large, beautiful, black and yellow beetle is a classic harbinger of fall by virtue of its late-season adult activity period and affinity to flowers of goldenrod (Solidago) and snakeroot (Eupatorium). Compared to the locust borer, however, it is larger, chunkier, and more boldly marked, and despite the commonness of goldenrod flowers it is far less commonly encountered than the locust borer due to the more restricted habitat preferences of the larval host plant (false indigo—Amorpha fruticosa).

Megacyllene decora
The beetle in these photos is one of two that I found in late September at a site in the lowlands of southeastern Missouri. I’ve not seen the beetle at this site before, but I knew it must occur here because of the stands of false indigo that I noted during an earlier visit to the site. Considering the large number of plants present, two beetles is much less than I would have expected to see (in fact, both beetles were found in a single patch of goldenrod). I have previously featured this species (see A classic fall ‘bycid) from a site about 50 miles east of this one. At that site also only a few beetles were seen despite an abundance of larval host plants (but the adults occurring on snakeroot flowers instead of goldenrod). Only twice have I seen this species in numbers that I would consider plentiful (both times in western Missouri).

Megacyllene decora
Amorpha borers and locust borers are part of a larger complex of black and yellow insects that visit goldenrod flowers in the fall. These include a variety of bees, wasps, and other beetles (e.g., the delta flower scarab, Trigonopeltastes delta—family Scarabaeidae), but perhaps the most abundant is the goldenrod soldier beetle, Chauliognathus pensylvanicus—family Cantharidae (also called the Pennsylvania leatherwing). One can presume that any or all of these species serve as models for the longhorned beetles—bees and wasps are obviously protected from most predators by their ability to sting, and the bodies of soldier beetles are chemically protected by cantharidin, a highly toxic terpenoid that causes blistering and irritation of mucous membranes at low doses and can be fatal at higher doses. As the mimics, amorpha borers and locust borers could be expected to be less abundant than the models. However, considering how difficult-to-see these beetles can be when sitting on goldenrod flowers, their black-and-yellow coloration seems as though it could just as easily serve a cryptic function. It is even possible that mimicry and crypsis both have contributed to evolution of these beetle’s coloration.

Ted C. MacRae 2014

The lesser of two jewels

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.


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 AgrilusU. 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

His name is Ralph!


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

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

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

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

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

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

”Sir, what’s your name?”

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

”Uh, his name is…”

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


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

Copyright © Ted C. MacRae 2013

Best of BitB 2012

Welcome to the 5th Annual “Best of BitB”, where I pick my favorite photographs from the past year. 2012 was one of the most intensive travel years I’ve ever had—I spent 8 weeks in Argentina from February through April, made separate trips to Puerto Rico and Arkansas in May (bracketing a personal week in California), traveled almost weekly to Illinois and Tennessee from June to September (interrupted by a personal week in Florida in July), toured the southeastern U.S. (Arkansas, Louisiana, Mississippi and Georgia—great food!) in early September, chased tiger beetles in Oklahoma, Texas and Arkansas in late September, went back to Argentina for a week in October, and capped off the travel year by attending the Entomological Society of America Annual Meetings in Knoxville, Tennessee (for the first time in more than 10 years!)—whew! While many would cringe at such a travel load, I am among the lucky few who actually get paid for doing something that is also my hobby—entomology! This gives me ample opportunity to further hone my photography skills (nine of the 13 photos I’ve selected below were actually taken while I was on business travel), resulting in two key accomplishments this year—my first ever photography talk at the ESA’s insect photography symposium and my first commercial sales (look for the BitB commercial site to go online in 2013).

Enough blather! Here are my favorite BitB photographs from 2012. Click the link in the text below the photo to see the original post. I would greatly appreciate knowing if you have a favorite (and why)—your feedback will be enormously helpful to me as I continue to learn and develop as a photographer.  For those interested, here are my previous year picks for 2008, 2009, 2010 and 2011. And, as always, thank you for your readership!

Spintherophyta (?) sp. in flower of Abutilon pauciflorum | Buenos Aires, Argentina

From  (posted 2 Feb). One of my 2012 learnings was that sometimes a photograph that is not so close is more effective than one that is as close as possible. In one of my earlier attempts at “not-so-close” macrophotgraphy, the soft colors of the flower compliment the brash shininess of the tiny leaf beetle that has been feeding on its pollen. Pink lines lead the eye directly to the subject and create a pleasing composition, and pollen grains stuck to the beetle—a distraction in some situations—add to the miniature natural history story of the photo.

Apiomerus flavipennis with stink bug prey and kleptoparasitic flies | Chaco Province, Argentina

From  (posted 11 Mar). I selected this photo solely for the complex natural history story drama it shows—stink bug (Piezodorus guildenii) feeding on soybean becomes prey of an assassin bug (Apiomerus flavipennis), with volatiles from the chemicals it emitted in a vain attempt to defend itself serving as cues to kleptoparasitic flies (families Milichiidae and Chloropidae) that benefit from the assassin bug’s labors.

Planthopper nymph | Buenos Aires Province, Argentina

From  (posted 26 Mar). Another learning that I began putting into practice in 2012 was the use of low perspective for compositional impact. The cryptic coloration of this planthopper nymph (family Fulgoridae) made it almost invisible on the branch on which it was sitting when viewed from a normal “top-down” human perspective. Getting “down under” it, however, brought the nymph to life and emphasized its unusual form.

Megabaris quadriguttatus | Corrientes Province, Argentina

From  (posted 12 Apr). I spent much of 2012 working on the “blue sky background” technique, with these weevils from northern Argentina representing one of my better attempts. Macrophotography of insects with a blue sky background involves setting exposure, ISO, and aperture to achieve two separate exposures—full flash illumination of the subject for maximum depth-of-field, and ambient light from the sky to create a clean, uncluttered, natural-looking background. In this shot I managed to achieve an almost ideal shade of blue to compliment the wild black, white and red colors of the beetles. (My one criticism of the photo is having clipped one of the beetle’s feet.)

Bombylius sp. cf. mexicanus | Scott Co., Missouri

From  (posted 16 May). This photo is unusual if nothing else. Focus, lighting, depth-of-field, and composition are all better than can be hoped for in a single shot, but the subject—perfectly alive—is in a most unusual position. Read the original post to find out how this happened.

Perisphaerus sp. (a pill roach) | Vietnam (captive individual)

From  (posted 27 May). White-box photography is an excellent technique for clean, uncluttered photographs of insects, but it also isolates them from their natural surroundings and limits their natural history appeal. The best white-box photos are those that highlight a key feature or behavior of the subject—in this case a pill roach’s comically conglobulating defensive posture.

Micronaspis floridana (Florida intertidal firefly) larva | Pinellas Co., Florida

From  (posted 31 July). Here is another photo whose back story played a big part in its selection. This firefly larva not only represents a rare Florida-endemic species but was also first seen by my then 12-year old nephew, who willingly accompanied me through a dark, spooky salt marsh in the middle of a humid Florida night to see what he could learn. The lesson here for budding natural historians (and old-timers like me) cannot be overstated!

Arctosa littoralis (beach wolf spider) | Lewis Co., Missouri

From  (posted 23 Aug—prelude to  posted 28 Aug). Those who follow this blog know of my obsession with close-up portraits, and while tiger beetles are the subjects I most commonly photograph in this manner, I am always on the lookout for good subjects in other taxa. This wolf spider “face” almost looks human, with “two” eyes, two “nostrils” and a shiny upper lip above huge (albeit hairy) buck teeth! It’s enough fill-the-frame spidery goodness to melt (or explode) the heart of even the most ardent arachnophobe!

Anticarsia gemmatalis (velvetbean caterpillar) egg on soybean leaf

From Life at 8X—Guide to lepidopteran eggs on soybean (posted 3 Sep). “Life at 8X” was a new series I introduced this year, featuring insects photographed at magnifications testing the upper limit of my equipment and photographic skills. Diffraction is the chief difficulty with magnifications as high as this and is the primary flaw in the above photograph. Nevertheless, such view of a moth egg on the underside of a soybean leaf provides a spectacular view of the otherwise unseen micro-world that lives right beneath our noses.

Megacyllene decora (amorpha borer) on snakeroot flowers | Mississippi Co., Missouri

From  (posted 12 Sep). This second example of “blue sky background” was taken later in the year and was considerably more difficult to capture than the first because of the larger size of the subject and resulting need for a longer focal length macro lens. Getting a well-lit, focused, and composed image with a desirable shade of blue in the background depended not only on finding the proper camera settings, but also secure body and camera bracing techniques for this completely hand-held shot.

Cicindelidia politula politula (Limestone Tiger Beetle) | Montague Co., Texas

From  (posted 28 Sep). I will go ahead and say it—this is my favorite photograph of 2012. As discussed under the first entry, panning back from the subject can allow for some very interesting compositions. This photo combines charismatic pose by a wary subject with panning back and low perspective to create an image that scores high in both natural history and aesthetic appeal.

Calosoma sayi (black caterpillar hunter) | New Madrid Co., Missouri

From Black is beautiful! (posted 7 Nov). Of course, close-as-possible can also be used to create striking photos, especially if the subject exhibits features that are best seen up close. Anything with jaws fits the bill in my book, and highlighting the mandibular sculpturing of this caterpillar hunter (a type of ground beetle) required precise angling of the flash heads for maximum effect.

Cicindela repanda (Bronze Tiger Beetle) | St. Louis Co., Missouri

From  (12 Nov). This final selection is not a rare species, but it is as close as I have come to what I consider the “perfect” tiger beetle macrophotograph—a close, low angle, lateral profile of an adult in full-stilt posture (a thermoregulatory behavior), well lit, perfectly focused, and with a dynamic but pleasingly blurred background. It’s a perfect storm of a photo that took the better part of two hours to achieve—rarely do all of these elements come together in a hand-held photograph of an unconfined tiger beetle in its native habitat.

Well, there you have it. I hope you’ve enjoyed my selections, and again please do let me know if you have a personal favorite. See you in 2013!

Copyright © Ted C. MacRae 2012

The gloriously dichromatic Dasymutilla gloriosa

I have a small collection of velvet ants (family Mutillidae) that I’ve accumulated over the years—not through active collection but more as bycatch from my beetle hunting operations. Velvet ants are, of course, not ants at all, but wasps, and as such the females are—like their winged relatives—quite capable of delivering a painful sting if mishandled. They also tend to be seen running rather frenetically across the ground, making them difficult to guide into a collection vial or grab with forceps. You’ve gotta really want ’em if you want to collect them. Still, even though I don’t study them I find them interesting enough to pick up on occasion, and with most groups outside of my area of focus the hope is that eventually they will end up in the hands of somebody who actively studies the group. Such is now the case with my mutillid collection, which will be shipped this week to another collector specializing in the group. In return I will be filling some holes in European representation of my collection of Cerambycidae.

Dasymutilla gloriosa, female | Brewster Co., Texas

Dasymutilla gloriosa, female | Brewster Co., Texas

Without question, the most interesting mutillid species that I’ve encountered is Dasymutilla gloriosa. All mutillids are sexually dimorphic, as only the males are winged, but most also tend to be sexually dichromatic to a greater or lesser degree. No species I am aware of takes this to the same level as D. gloriosa! The males (photo below) are rather typically colored compared to other species in the genus, but the females (photo above) are densely covered with long, strikingly white hairs. While this would seem to make them quite conspicuous, the true effect is the exact opposite as they easily confused with fuzzy plant seed. For this reason they are commonly called thistledown velvet ants. I encountered the female in west Texas in 2003 while walking a mountain trail and at first thought it was the fuzzy seed of a creosote bush (Larrea tridentata) being blown by the wind—except there was no wind! It took me a little while looking closely at it before I could figure out what it actually was. This is the only female of this species that I’ve seen in the wild, and I’ll be a little sad to see it sent to another location.

Dasymutilla gloriosa, male | Riverside Co., California

Dasymutilla gloriosa, male | Riverside Co., California

The male also is the only one I’ve encountered—or at least taken the trouble to collect. I would have never suspected this male, which I collected in southern California in 1991, was the same species as the female that I collected many years later. My thanks to Kevin Williams, who provided the identifications for both of these specimens.

Also called the ''thistledown velvet ant''

Also called the ”thistledown velvet ant”

Copyright © Ted C. MacRae 2012