Mylabris oculatus in South Africa

April 15, 2010October 10, 2011 / Ted C. MacRae / 16 Comments

Mylabris oculata, the CMR bean beetle, is a large, conspicuously-colored beetle in the family Meloidae (blister beetles) that I saw quite commonly during my stay in South Africa. “CMR” refers to the Cape Mounted Rifle Corps, a police force in the old Cape Colony whose uniforms sported black and yellow bands that resemble the colors of this beetle.

Blister beetles as a whole are, of course, well known for their chemical defenses, primarily cantharidin (the active ingredient in ‘Spanish Fly’, an extract of a European species of blister beetle). This terpenoid compound is a painful irritant, especially when coming into contact with mucous-lined membranes such as those of the gatrointestinal and urinary tracts. Blister beetles emit body fluids containing cantharidin from joints on the legs when disturbed, giving any would-be predators a foul-tasting appetizer. As we have so often seen, insects containing such effective defenses are often aposematically colored to advertise the fact, allowing them to brazenly lumber about fully exposed during the day with little to fear. If there ever was an insect that screamed aposematic, it is M. oculatus with its boldy contrasting black and yellow elytra and hot-orange antennae.

These beetles, however, are more than just a frustration for hungry birds, but also a serious pest of numerous ornamental, fruit and vegetable crops (Picker et al. 2002). Large numbers of adults congregate on plants and preferentially feed on the flowers. In the more natural settings where I was encountering these beetles, they were most often seen on flowers of Acacia spp. or (as in the above photo) Dichrostachys cinerea in the family Fabaceae. To be honest, they became quite a source of frustration for me as well – not because of their distastefulness or pestiferous habits, but because of their role as the model in a mimicry complex. It was the mimic that I was after, and since mimics tend to be much less common than their models, I had to look at a lot of M. oculatus to find the few specimens of the species I was after.

Pop quiz: Can anybody name the mimic?

Back to their chemical defenses – I’ve often wondered just how poisonous blister beetles really are, especially to humans. Here in the U.S., their main importance is as contaminants in alfalfa hay fed to cattle and horses. Deaths from severely contaminated forage do occur, but this is dependent upon the cantharidin content of the species and their abundance within the hay. The highest reported cantharidin content for a blister beetle is 5.4% dry weight in Epicauta vittata. Calculations based on this figure and the lethal dose for a 1000-lb horse indicate that around 100 such beetles would need to be eaten to receive a fatal dose. This seems to make the claim that a single beetle can kill a human a little far-fetched. However, M. oculatus are big beetles – more than a full inch in length and bulky. In this regard, I found an interesting tidbit at the TrekNature website. Clarke Scholtz is an entomologist at the University of Pretoria, and when asked, “Is it true that their poison can kill a human being?”, he responded:

Yes; they are poisonous enough to kill people – especially a big beetle… The poison is very toxic and actually causes collapsed tissue. It would also depend on the weight of the person, as with any other toxin. The poison of a CMR beetle, that is dried and powdered, is sufficient to kill a 70kg human.

REFERENCE:

Picker, M., C. Griffiths and A. Weaving. 2002. Field Guide to Insects of South Africa. Struik Publishers, Cape Town, 444 pp.

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Euhagena nebraskae in Kansas

February 25, 2010October 10, 2011 / Ted C. MacRae / 16 Comments

Gypsum Hills region of south-central Kansas (Barber Co.)

One of my favorite destinations for insect collecting is the Gypsum Hills region in Barber County of south-central Kansas. I first went there in May 1986 after seeing a diverse selection of more typically Texan Buprestidae that J. Richard Heitzman, an iconic lepidopterist in the Kansas City area and author of Butterflies & Moths of Missouri, had collected there on soapberry (Sapindus saponaria). I had my own success with Buprestidae as well during that trip, but in recent years I have returned to Barber County several times during the fall to look for one of North America’s most beautiful tiger beetles, Cicindela pulchra (Beautiful Tiger Beetle). This species had been recorded in the area by the well-known cicindelophiles Ron Huber and Dave Brzoska, who suggested that I look in the red clay hills just west of Medicine Lodge. My first trip to look for this beetle in 2004 was unsuccessful, and I suspect the early September timing of my trip may have been a tad too early. I returned again in 2005, this time in early October and also enlisting the help of local entomologist “Beetle Bill” Smith, who knew of a population on private land near his home in Hardtner (south of Medicine Lodge). Although at first it looked like success might again elude me, in the end I saw a robust population of these spectacular beetles and published an account of that marvelous experience (MacRae 2006).

As with so many of the things that I have seen over the years, they came before my interest in photography, and I now find myself wanting to re-find some of the more spectacular insects that I’ve previously found so that I can properly photograph them. Such is the case with C. pulchra, so in October of last year I returned to Barber County in hopes of seeing this species armed not only with an aerial net, but also a Canon 50D. Sadly, this would not come to pass – the same sudden cold snap that dashed my hopes of finding this species in nearby Woodward/Major Counties, Oklahoma would keep any tiger beetle activity to a bare minimum the following day in Barber County as well. Despite bright sunny skies, I would see only two tiger beetles the entire day, both representing the dreadfully ubiquitous Cicindela punctulata (Punctured Tiger Beetle). Not all insect activity, however, was squelched, and after scanning the red soils for an hour or so without seeing the object of my desire I began to notice some of these other not-so-temperature-finicky species. One of the more magnificent of these is shown in the photo below — Euhagena nebraskae in the family Sesiidae (cess-EYE-id-ee) (formerly Aegeriidae).

Euhagena nebraskae (Lepidoptera: Sesiidae)

Although I wasn’t sure of the species at first, I recognized it immediately as a clearwing moth. I had an interest in this family of moths for a time in my early days as a field entomologist with the Missouri Department of Agriculture. Many species are important pests of woody plants in orchard and ornamental landscapes, and it was during that time that synthetic pheromones became widely used for monitoring purposes. I often walked around with a pheromone tag pinned to my bag to attract the male moths — it was fun watching people seeing these moths “buzzing” me and thinking I was under attack by the wasps that they so effectively mimic (despite my calmness in these situations, I still found it hard to actually grab one from the air with my hand – so convincing is their mimicry).

Euhagena nebraskae is one of two species in the genus in North America, both of which develop as larvae in the roots of plants in the evening primrose family (Onagraceae) (Eichlin and Duckworth 1988). In fact, I had seen its congener — E. emphytiformis — many times in the 1980s in pheromone traps that I used to place in the glades of Jefferson County just south of St. Louis, where it presumably breeds in one or both of two Oenetherea species growing there (O. gaura and O. macrocarpa). Euhagena nebraskae is a more western species that does not occur in Missouri, occurring instead across the Great Plains west to California and from southern Alberta and Saskatchewan south to Mexico. It is likely that many entomologists never see this species, as adults are active only during late fall. Thus, its perception as an uncommon species may be an artifact of its late seasonality.

I thought it odd that nearly every individual that I saw was sitting on the ground rather than perched higher on a plant. At first I wondered if the cold temperatures were a reason for this, perhaps causing the moths to seek out the ground as a source of radiant heat. This seems doubtful, however, since females always seemed to be “calling” – their tufted abdominal tips raised in the air with the scales spread apart, apparently releasing pheromone. I was fortunate to find this mating pair, which shows nicely the rather high degree of sexual dimorphism seen in these moths. Note the much more highly bipectinate antennae of the male (pectinate = resembling a comb, bipectinate = ‘teeth’ on both sides of the main stem) versus the simple antennae of the female — males use their antennae for detecting female pheromones, and the bipectinate form presumably provides greater surface area for placement of sensory pores. Note also the male’s smaller size, “hairier” head and thorax, and greater amount of white coloration on the abdomen and wings. Engelhardt (1946) supposed that the excessive hairiness of adult Euhagena species was an adaptation to their late-season emergence (principally during October and sometimes as late as November), a time when frosty nights prevail in their high-elevation haunts.

REFERENCES:

Eichlin, T. D. and W. D. Duckworth. 1988. The Moths of America North of Mexico, Fascicle 5.1, Sesiodea: Sesiidae. Wedge Entomological Research Foundation, Washington, 176 pp.

Engelhardt, G. P. 1946. The North American clear-wing moths of the family Aegeriidae. Bulletin of the United States National Museum 190:1-222.

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

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Monday Moth: White-tipped Black Moth

November 9, 2009October 10, 2011 / Ted C. MacRae / 25 Comments

Melanchroia_chephise_IMG_1241_1200x800_enh

Photo details: Canon 100mm macro lens on Canon 50D (manual mode), ISO-100, 1/250 sec, f/22, MT-24EX flash w/ Sto-Fen diffusers.

When is a ctenuchid moth not a ctenuchid moth? When it’s a White-tipped Black Moth (Melanchroia chephise) in the family Geometridae!

I may be a beetle guy, but I also consider myself a competent general entomologist. What is a competent general entomologist? Someone who can identify any insect to order at first glance and a majority of them to family – regardless of one’s own taxa of expertise. Thus, when I encountered this mating pair of moths on the outside wall of my sister-in-law’s condominium in Seminole, Florida, I “recognized” them as something in what I learned as the family Ctenuchidae (later subsumed within the Arctiidae, first as a subfamily and now as several disparate tribes). They had all the hallmarks of ctenuchids—black and red coloration, narrowish wings with light colored patches, and about the size of the wasps that they presumably mimic. Upon my return to St. Louis, I sat down to identify the moths—confident that their distinctive appearance would lead to the quick ID that never materialized after scanning through all of the ctenuchine pages at BugGuide. Frustrated, I resorted to posting the photo on the site’s ID Request, never questioning my ctenuchine placement. Precisely 4 minutes later, the moths were identified by John Maxwell as Melanchroia chephise and moved to their proper place—among the 50 other adult photographs of this species that can be found on the site! I might as well have failed to identify a monarch butterfly!

Melanchroia chephise is apparently common in the American tropics, reaching its northern distributional limit along the coastal plains of Florida and Texas but straying further north in certain years. Larvae feed on several plants in the family Euphorbiaceae, primarily Breynia and Phyllanthus species. The adult coloration strikes me as obviously aposematic (warning coloration), but I could find no specific references to this. However, considering that euphorbiaceous plants are famous for their diverse arsenal of latex and irritant toxins (e.g., diterpene esters, alkaloids, glycosides, ricin-type protein toxins, etc.), it seems reasonable to presume that Melanchroia larvae have evolved mechanisms for sequestering one or more of these compounds. NABA South Texas states that adults of this species are probably mimics of the Red-bordered Pixie (Melanis pixe), an aposematic metalmark butterfly also of Neotropical distribution that reaches south Texas (but not Florida). Personally, I don’t really see the resemblance (but then, nor am I an avian predator). I suppose it’s possible that a species such as this can employ different defense strategies in different parts of its range, relying on Batesian mimicry in areas where suitable models occur and aposematism in areas where they don’t, but I have to admit that I’m now straying well outside the coleopteran-centric bounds of my expertise.

Ospriocerus abdominalis

August 18, 2009July 22, 2013 / Ted C. MacRae / 18 Comments

Photo details: Canon 100mm macro lens on Canon EOS 50D, ISO 100, 1/250 sec, f/14, MT-24EX flash 1/4 power w/ diffuser caps.

My dipteran digression continues with this photograph of the robber fly, Ospriocerus abdominalis (Diptera: Asilidae). More than just a pretty picture, this represents yet another apparently new state record that I and my colleague Chris Brown discovered a few weeks ago during our 2-day survey of Missouri’s critically imperiled hilltop prairies in the extreme northwest corner of the state. Like the previously discussed Cylindera celeripes (swift tiger beetle) and Beameria venosa (a prairie-obligate species of cicada), O. abdominalis has not previously been recorded further east than Nebraska, Kansas, Oklahoma and Texas. This large fly is a grassland denizen that ranges over western North America and into Mexico (Cannings 1998, as Ospriocerus aeacus). It is somewhat suggestive of a mydas fly, although its short antennae immediately identify it as a robber fly (mydas flies have elongate clubbed antennae). It also reminds me of the magnificent western robber fly Wyliea mydas by its mimetic, wasp-like coloration – presumably modeled after spider wasps of the genus Pepsis and Hemipepsis (Hymenoptera: Pompilidae) – but is distinguished by its black body and wings with red dorsal coloration on the abdomen (W. mydas has the abdomen wholly black and the wings red). While not quite as handsome as W. mydas, it is impressive nonetheless.

The dry hilltop prairie remnants in which O. abdominalis, B. venosa, and C. celeripes were found are associated with the Loess Hills, a unique landform along the western edge of Iowa that reaches its southern terminus in extreme northwest Missouri. Due to their extreme rarity and vulnerability to woody encroachment and anthropogenic degradation, these remnant habitats are considered one of Missouri’s most critically imperiled natural communities. Only about 50 acres of original habitat remain, and of this only half is in public conservation ownership. Many of the plants and animals found in these habitats represent hypsithermal relicts that migrated eastward during a dry and warm period after the last ice age and were then “left behind” in pockets of relictual habitat as a return to cooler, wetter conditions forced the main populations back to the west. More than a dozen plants and two vertebrates occurring in these prairies are listed as species of conservation concern. As is typically the case, the flora and vertebrate fauna of these remnant habitats have been fairly well characterized, while precious little attention has been given to the vastly more diverse invertebrate fauna. As we begin to study the insects of these habitats more carefully, we are almost sure to find a great many species that are more typically found further to the west and that live nowhere else in Missouri. Their continued presence in the state will be wholly dependent upon the critically imperiled habitats in which they live, making conservation and restoration of the remaining loess hilltop prairie remnants in Missouri all the more important.

My thanks to Eric Fisher and Herschel Raney for confirming the identity of O. abdominalis.

REFERENCES:

Cannings, R. A. 1998. Robber Flies (Insecta: Diptera: Asilidae), in Smith, I. M., and G. G. E. Scudder, eds. Assessment of species diversity in the Montane Cordillera Ecozone. Burlington: Ecological Monitoring and Assessment Network.

Pyromorpha dimidiata

June 12, 2009October 10, 2011 / Ted C. MacRae / 13 Comments

Photo details: Canon MP-E 65mm 1-5X macro lens on a Canon EOS 50D, ISO 100, 1/200 sec, f/16, MT-24EX flash 1/8 power through diffuser caps

Despite being a coleopterist, I was somewhat surprised when I realized that I have not yet posted a Lepidoptera photo on this site – especially considering their abundance, diversity (2nd largest order of insects), and overall photogenicity. Time to change that. I encountered this pretty little moth at Reifsnider State Forest in Warren Co., Missouri.

Pyromorpha dimidiata (orange-patched smoky moth) is one of the so-called “leaf-skeletonizer moths” in the family Zygaenidae. This particular species is distinguished from a similar, though unrelated species in our area, Lycomorpha pholus (black-and-yellow lichen moth, one of the subfamilies of the tiger moths, or family Arctiidae), by the black hind margin of the forewing and its phenology – L. pholus adults don’t appear until late summer.

Larvae of P. dimidiata are reported to feed on leaf litter, especially oak leaves. Oaks are present in great quantity and diversity here in Missouri, and in fact this species was photographed in one of Missouri’s finest examples of a mature white oak (Quercus alba) forest – uncommon in Missouri due to the generally less mesic conditions of our upland habitats.

Perhaps I like this moth because it apparently belongs to a mimicry complex involving net-winged beetles (family Lycidae), in particular the species Calopteron terminale (end band net-wing). Lycomorpha pholus also participates in this mimicry complex; however, unlike that species, P. dimidiata is itself toxic as well – all life stages of this moth contain hydrogen cyanide, which they manufacture rather than obtaining from host plants (Scoble 1992). Thus, the Calopteron-Pyromorpha mimicry complex appears to be an example of Müllerian mimicry, where both the model and the mimic are toxic.

REFERENCE:

Scoble, M. J. 1992. The Lepidoptera. Form, Function and Diversity. Oxford University Press, Oxford, 404 pp.

Bizarre, beautiful extremes

February 15, 2009October 10, 2011 / Ted C. MacRae / 8 Comments

No niche, it seems goes unfilled. Specialization is likely to be pushed to bizarre, beautiful extremes.–E. O. Wilson, The Diversity of Life

Wilson didn’t mention treehoppers specifically when he made the above quote, referring to the exuberance of extreme behavioral and morphological adaptations seen in the biota of the tropics, but he could have just as easily led off with them. Treehoppers (order Hemiptera, family Membracidae) are well-known for their variety of oddly grotesque shapes resulting from a curiously inflated pronotum – presumably having evolved to resemble thorns and buds on their host plants, or the ants that vigorously defend numerous treehopper species in exchange for their sweet honeydew, or perhaps to aid in the dispersal of volatile sex pheromones (an attractive hypothesis but lacking experimental support). Despite inordinate attention in relation to their low economic importance, it remains that the pronotal modifications of many treehoppers are so bizarre that they continue to defy any logical explanation.

I must admit that, despite my passion for beetles, treehoppers were my first love. (Well, actually anything that I could bring home from my solo wanderings in the urban woodlands and vacant lots near my childhood home and keep alive in a terrarium was my first true love, but from an academic standpoint, treehoppers were the first group to arouse my taxonomic interest as I began my transformation from child collector to serious student.) I had just begun graduate school in the Enns Entomology Museum under the late hemipterist Tom Yonke to conduct leafhopper host preference and life history studies, and although far more Cornell drawers in the museum contained Cicadellidae, it was the treehopper drawers that I found myself rifling through each afternoon after completing the day’s thesis duties. Despite their lesser number, the treehopper drawers had recently benefited from the attentions of a previous student, Dennis Kopp, whose efforts during his time at the museum concentrated on collecting treehoppers from throughout Missouri and culminated in the four-part publication, The Treehoppers of Missouri (1973-1974). I was enamored by these little beasts – specifically by their exaggerated pronotum – and started collecting them whenever I could on my forays around the state surveying for leafhoppers. They were closely enough related to leafhoppers to make them relevant to my work, only cooler – like leafhoppers on steroids! With The Treehoppers of Missouri as my bible and my desk located a half dozen footsteps from the largest treehopper collection within a several hundred mile radius, I delved into their taxonomy and, for a time, considered a career as a professional membracid taxonomist.

Fast forward nearly 30 years, and my involvement as a taxonomist is neither professional nor deals with membracids. Beetles have taken over as my focal taxon, and I conduct these studies strictly as an avocation. Still, I continue to collect treehoppers as I encounter them, and although such efforts have been largely opportunistic, I’ve managed to assemble a fairly diverse little collection of these insects as a result of my broad travels. Much of this has occurred in the New World tropics, and it is this region that is the center of diversity for the family Membracidae (fossil evidence suggests that subfamily diversification and subsequent New World radiation began during Tertiary isolation about 65 million years ago after South America separated from Africa, since only the primitive subfamily Centrotinae occurs in both the Old and the New Worlds – all other subfamilies are restricted the New World (Wood 1993)). Every now and then, as I accumulate enough material to fill a Schmidt box, I sit down and study what I’ve collected, comparing it to my meager literature to attempt identifications. For material I collect in eastern North America, this works fairly well, as there have been a number of publications covering different parts of this area. Outside of this area, however, my only hope is to entice one of the few existing membracid specialists into agreeing to look at what I’ve accumulated and ask for their help in providing names, in exchange for which they will be granted retention privileges to benefit their research.

Most recently, I was able to convince Illinois Natural History Survey entomologist Chris Dietrich to take a look at the material I had accumulated during the past ten years or so, which included many specimens from Mexico and a smattering from other world areas, including South Africa. Chris did his doctoral work at North Carolina State University under “Mr. Membracid” himself, Lewis Deitz, and has since been conducting evolutionary and phylogenetic studies on Membracidae and the related Cicadomorpha. I recently received this material back from Chris (photo above), the majority of which he had been able to identify to species – only a few specimens in the more problematic genera were left with a generic ID.

Campylocentrus sp. (Mexico: Oaxaca)

Hyphinoe obliqua (Mexico: Oaxaca)

Poppea setosa (Mexico: Puebla)

Umbonia reclinata (Mexico: Oaxaca)

Umbonia crassicornis male (Mexico: Puebla)

Umbonia crassicornis female (Mexico: Puebla)

The selection of photos here show a sampling of some of the more interesting forms contained within this batch of newly identified material – all of which hail from southern Mexico. Campylocentrus sp. is an example of the primitive subfamily Centrotinae, distinguished among most membracid subfamilies by the exposed scutellum (not covered by the expanded pronotum). Hyphinoe obliqua is an example of the largely Neotropical subfamily Darninae, while Poppea setosa represents one of the more bizarre ant-mimicking species of the subfamily Smiliinae. Umbonia is a diverse genus in the subfamily Membracinae, occurring from the southern U.S. south into South America. Umbonia crassicornis is one of the most commonly encountered species in this genus, with the photos here showing the high degree of sexual dimorphism it exhibits. As membracids go, these species are quite large (10 mm in length from frons to wing apex for Campylocentrus sp. and P. setosa, a slightly larger 11-13 mm for the others); however, the many smaller species in this family are no less extraordinarily ornamented. I’ve also included a photo (below) of one of the drawers from the main collection after incorporating the newly identified material – this drawer represents about half of my treehopper collection, with the largely Nearctic tribe Smiliini and the primitive family Aetalionidae contained in another drawer. In all, the material contained one new subfamily, six new tribes, 13 new genera¹, and 30 new species for my collection. For those with an appetite for brutally technical text, a checklist of the species identified, arranged in my best attempt at their current higher classification, is appended below (any treehopper specialist who happens upon this should feel free to set the record straight on any errors). For each species, the country of origin (and state for U.S. specimens) is indicated along with the number of specimens, and higher taxa new to my collection are indicated with an asterisk(*). Don’t worry, I didn’t type this up just to post it here – it’s a cut/paste job from my newly updated collection inventory for Membracoidea. Happy reading!

¹Wildly off topic, and perhaps of interest only to me, but two of the genera represented in the material are homonyms of plant genera: Oxyrhachis is also a Madagascan genus of Poaceae, and Campylocentrus is a Neotropical genus of Orchidaceae. Scientific names of plants and animals are governed by separate ruling bodies (ICBN and ICZN, respectively), neither of which specifically prohibit (but do recommend against) creating inter-code homonyms. The number of such homonyms is surprisingly high – almost 9,000 generic names have been used in both zoology and botany (13% of the total in botany) (source). Fortunately, there is only one known case of plant/animal homonymy fr BOTH genus- and species-level names – Pieris napi japonica for a subspecies of the gray-veined white butterfly (Pieridae) and Pieris japonica for the popular ornamental plant Japanese andromeda (Ericaceae).

REFERENCES:

Kopp, D. D. and T. R. Yonke. 1973-1974. The treehoppers of Missouri: Parts 1-4. Journal of the Kansas Entomological Society 46(1):42-64; 46(3):375-421; 46(3):375-421; 47(1):80-130.

Wood, T. K. 1999. Diversity in the New World Membracidae. Annual Review of Entomology 38:409-435.
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Superfamily MEMBRACOIDEA
Family MEMBRACIDAE
Subfamily CENTROTINAE

*Tribe BOOCERINI
*Campylocentrus curvidens (Fairmaire) [Mexico] – 4
Campylocentrus sp. [Mexico] – 1

*Tribe GARGARINI
*Umfilianus declivus Distant [South Africa] – 3

*Tribe OXYRHACHINI
*Oxyrhachis latipes (Buckton) [South Africa] – 1

Tribe PLATYCENTRINI
Platycentrus acuticornis Stål [Mexico] – 11
Platycentrus obtusicornis Stål [Mexico] – 3
Platycentrus brevicornis Van Duzee [USA: California] – 7
Tylocentrus reticulatus Van Duzee [Mexico] – 4

*Tribe TERENTIINI
*Stalobelus sp. [South Africa] – 1

*Subfamily HETERONOTINAE

*Tribe HETERONOTINI
*Dysyncritus sp. [Argentina] – 1

Subfamily MEMBRACINAE

Tribe ACONOPHORINI
Aconophora sp. female [Mexico] – 1
*Guayaquila xiphias (Fabricius) [Argentina] – 7

Tribe HOPLOPHORIONINI
Platycotis vittata (Fabricius) [USA: Arizona, California] – 3
Umbonia crassicornis (Amyot & Serville) [Mexico] – 73
Umbonia reclinata (Germar) [Mexico] – 8

Tribe MEMBRACINI
Enchenopa binotata complex [Mexico] – 1
Enchenopa sp. [Argentina] – 6

Subfamily DARNINAE

Tribe DARNINI
Stictopelta nova Goding [Mexico] – 9
Stictopelta marmorata Goding [USA: Texas] – 1
Stictopelta pulchella Ball [Mexico] – 11
Stictopelta varians Fowler [Mexico] – 3
Stictopelta sp. [USA: Arizona, California] – 5
Stictopelta sp. [Mexico] – 5
Stictopelta spp. [Argentina] – 6
*Sundarion apicalis (Germar) [Argentina] – 2

*Tribe HYPHINOINI
*Hyphenoe obliqua (Walker) [Mexico] – 1

Subfamily SMILIINAE

Tribe AMASTRINI
Vanduzeea triguttata (Burmeister) [USA: Arizona] – 2

Tribe CERESINI
Ceresa nigripectus Remes-Lenicov [Argentina] – 3
Ceresa piramidatis Remes-Lenicov [Argentina] – 4
Ceresa ustulata Fairmaire [Argentina] – 1
Ceresa sp. female [Argentina] – 1
Poppea setosa Fowler [Mexico] – 11
Tortistilus sp. [USA: California] – 1

Tribe POLYGLYPTINI
*Bilimekia styliformis Fowler [Mexico] – 3
Polyglypta costata Burmeister [Mexico] – 18

Tribe SMILIINI
Cyrtolobus acutus Van Duzee [USA: New Mexico] – 1
Cyrtolobus fuscipennis Van Duzee [USA: North Carolina] – 1
Cyrtolobus pallidifrontis Emmons [USA: North Carolina] – 1
Cyrtolobus vanduzei Goding [USA: California] – 4
Cyrtolobus sp. [USA: Arizona] – 2
*Evashmeadea carinata Stål [USA: Arizona] – 4
*Grandolobus grandis (Van Duzee) [USA: Arizona] – 1
Ophiderma sp. [Mexico] – 1
Palonica portola Ball [USA: California] – 4
Telamona decora Ball [USA: Missouri] – 4
Telamona sp. [USA: Texas] – 1
*Telamonanthe rileyi Goding [USA: Texas] – 2
*Telonaca alta Funkhouser [USA: Texas] – 1
Xantholobus sp. [Mexico] – 1

Subfamily STEGASPINAE

Tribe MICROCENTRINI
Microcentrus perditus (Amyot & Serville) [USA: Texas] – 1
Microcentrus proximus (Fowler) [Mexico] – 1

Family AETALIONIDAE
Subfamily AETALIONINAE

Aetalion nervosopunctatum nervosopunctatum Signoret [Mexico] – 9
Aetalion nervosopunctatum minor Fowler [USA: Arizona] – 2
Aetalion reticulatum (Linnaeus) [Argentina, Uruguay] – 26

Tragidion confusion

February 2, 2009October 10, 2011 / Ted C. MacRae / 3 Comments

Back in October, I discussed a recent review of the cerambycid genus Tragidion, authored by Ian Swift and Ann Ray and published in the online journal Zootaxa. These gorgeous beetles mimic the so-called “tarantula hawks” (a group of large, predatory wasps in the family Pompilidae) and have been difficult to identify due to poorly-defined species limits, wide range of geographic variation, unusually high sexual dimorphism, and apparent potential for hybridization in areas of geographic overlap. Swift and Ray (2008) recognized seven North American and four Mexican species, including two newly described species and another raised from synonymy. It was an excellent work that provided much needed clarity based on examination of types and included detailed descriptions and dorsal habitus photographs of all species and separate keys to males and females to facilitate their identification. Unfortunately, my summary caused some confusion regarding species that occur in the deserts of southern Arizona, southern New Mexico and western Texas. In this post, I’ll clarify that confusion and provide details for distinguishing these species.

Formerly, it was thought that two species of Tragidion inhabited this region, with populations exhibiting smooth elytra and breeding in dead stalks of Agave and Yucca (Agavaceae) representing T. armatum and those exhibiting ribbed elytra and breeding in dead branches of a variety of woody plants representing T. annulatum. This concept dates back to the landmark monograph of the Cerambycidae of North America by Linsley (1962). Swift and Ray (2008) noted that Linsley’s concept of T. annulatum was based on an erroneously labeled type specimen, and that true T. annulatum referred to populations in California and Baja California (for which other names – now suppressed – were being used). This left the AZ/NM/TX populations attributed to T. annulatum without a name. The previously suppressed name T. densiventre was found to refer to populations inhabiting lowland habitats and breeding in Prosopis and Acacia (Fabaceae), but those occurring in montane habitats and breeding in Quercus (Fagaceae) represented an as yet undescribed species, for which the name T. deceptum was given. I included Swift and Ray’s figure of T. deceptum in my post – but mistakenly included the male of T. densiventre alongside the female of T. deceptum!

This error may never had been noticed, had it not been for the discriminating eyes of BugGuide contributor, Margarethe Brummermann. Margarethe is currently collecting photographs for a field guide to Arizona beetles and had photographed a male and female of a “ribbed” species in Montosa Canyon. Using the illustration of T. “deceptum” in my post, Margarethe concluded her specimens represented T. deceptum and asked me to confirm her ID. When I told her the specimens represented T. densiventre, her confusion was understandable (given that her male appeared identical to the T. “deceptum” male in my post). Further query on her part prompted me to do a little digging, and I discovered my error. The figure in my post has since been corrected – both that figure and a figure from Swift and Ray (2008) showing the male and female of T. densiventre are included below, along with additional information to allow their identification.

Tragidion densiventre Casey, 1912

Tragidion densiventre was formerly synonymized under T. auripenne (a rare species known from the four corners region of northern Arizona, southern Utah, southwestern Colorado, and northwestern New Mexico). Males of T. densiventre can be distinguished by their longer antennae, tawny-tan elytra and distinctly red-brown head, legs, and scape, while females have shorter antennae and the elytra red-orange. Both males and females of this species are distinguished from T. deceptum by their five elytral costae that curve inward toward the suture and extend to near the elytral apices, as well as their relatively narrower basal black band. Females of this species may be further distinguished from T. deceptum by their all black (or nearly so) antennae. Tragidion densiventre is found predominantly in xeric lowland desert habitats in Arizona, New Mexico, and west Texas (as well as northern Mexico). Larvae have been recorded developing in dead Prosopis glandulosa and Acacia greggii, and adults have been observed aggregating on sap oozing from stems of Baccharis sarothroides (Asteraceae) and flowers of larval host plants. Although the biology of this species has not been described in detail, it is likely that the observations of Cope (1984) for T. auripenne refer to this species. This is the classic T. “annulatum” commonly observed in the desert southwest.

Tragidion deceptum Swift & Ray, 2008

Tragidion deceptum superficially resembles T. densiventre due to its ribbed elytra; however, it is actually more closely related to the Mexican species T. carinatum. Like T. densiventre, the males exhibit longer antennae and tawny-tan elytra, while females have shorter antennae and orange-red elytra. However, the head, legs and scape of males are black, as in females of the species, rather than red-brown as in males of T. densiventre. Females exhibit distinctly annulated antennae, in contrast to the all black antennae of T. densiventre. Both males and females are distinguished from T. densiventre by the elytral costae – only four rather than five, not incurved towards the suture and extending only to the apical one-third of the elytra. In addition, the basal black band is very broad – exceeding the scutellum by 2 × its length. This species is similarly distributed across the desert southwest as T. densiventre but occurs in more montane habitats, where it breeds in recently dead branches of several species of Quercus. Like T. densiventre, adults are often found feeding and aggregating on Baccharis sarothroides, and in a few lower canyons bordering desert habitats in the Huachuca Mountains of southeastern Arizona this species and T. densiventre have been collected feeding alongside each other on the same Baccharis plants. Tragidion deceptum is one of several species in the genus (along with T. coquus in eastern North America) that have been collected using fermenting molasses traps (more on this in a future post).

REFERENCES:

Cope, J. 1986. Notes on the ecology of western Cerambycidae. The Coleopterists Bulletin, 38:27–36.

Linsley, E. G. 1962. The Cerambycidae of North America. Part III. Taxonomy and classification of the subfamily Cerambycinae, tribes Opsimini through Megaderini. University of California Publicatons in Entomology, 20:1-188, 56 figs.

Swift, I. and A. M. Ray. 2008. A review of the genus Tragidion Audinet-Serville, 1834 (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini). Zootaxa, 1892:1-25.

Tyrant ground beetles

January 13, 2009October 10, 2011 / Ted C. MacRae / 19 Comments

I return to my Afrikaans theme with a distinctive group of ground beetles (family Carabidae) called tyrant ground beetles or spotted ground beetles (tribe Anthiini). I think I prefer the former. This tribe is largely restricted to Africa and is especially diverse and abundant in the arid, sandy Karoo and Kalahari regions of southern Africa (Scholtz & Holm 1985). These beetles are large, powerful predators that rely on speed and agility for capturing prey, and since they are also flightless these characteristics come in handy for avoiding becoming prey themselves. Failing that, they employ chemical defense in the form of secretions from a pygidial gland located in the area of the ninth abdominal segment. The chemical cocktail within these secretions contains concentrated organic acids or quinone that can be squirted at potential predators in a strong jet. This is an effective deterrent to small mammalian and avian predators, and I suppose a careless beetle collector might also regret handling these beetles without due respect. These defensive spray capabilities give rise to another common name for the group, “oogpister” – an Afrikaner word that literally translates to (ahem) “eye pisser.”

During my time in Africa, Chuck Bellamy and I were primarily focused on collecting buprestids. However, we still couldn’t resist hanging an ultraviolet light in front of a sheet and searching the ground with flashlights at night to see what diversity of other African insects we might encounter. Truth be told, one of the non-buprestid groups that I’d really hoped to encounter was a near relative of these beetles – the so-called “monster tiger beetles” of the genus Manticora (family Cicindelidae¹). We never did see any monsters, but we did encounter several species of anthiine ground beetles around our encampment at Geelhoutbos farm near the Waterberg Range in Limpopo Provice. Anthia (s. str.) thoracica, the giant African ground beetle (above), was the most impressive of these. Click on the photo to see a larger version – only then will it begin to convey how truly appropriate such a common name is for this species. It is certainly the largest ground beetle that I have ever seen – a full 50 mm in length! That’s 2 inches, folks! This species is easily recognized by the depressed lateral expansions of the pronotum covered with dense white/yellow pubescence, and the slightly smaller male that I caught exhibits more elongated mandibles (though not so incredibly as in Manticora) and marvelous lobes extending backward from the pronotum.

¹ Increasingly placed within the Carabidae as subfamily Cicindelinae on the basis of molecular phylogenetic analysis, along with Paussinae and Rhysodinae (e.g., Beutel et al. 2008).

In addition to true Anthia, we saw two species of the subgenus Anthia (Termophilum)². The species shown right is A. (T.) omoplata³, with the common name “two-spotted ground beetle” (Picker et al. 2002). It was almost as large as its giant brother above, measuring 47 mm in length. Of this species, I only saw this one individual, but I did also find two individuals of a related species, T. fornasinii. Unfortunately I was unable to photograph the latter species, which is equally large but with the elytral white markings limited to a thin marginal band and the surface of the elytra bearing strong longitudinal intervals – a handsome beast, indeed! Picker et al. (2002) mention T. homoplatum being a diurnal hunter, but we found all of our anthiines active nocturnally.

² Treated variously in the literature as either a full genus or as a subgenus of Anthia. I follow Carabidae of the World, in which it is given subgeneric status. The name is often cited as “Thermophilum” in the literature, but this is an incorrect subsequent spelling according to Alexandre Anischenko (in litt.), coordinator/editor of Carabidae of the World.

³ Usually cited as “homoplatum” or “homoplata” in the literature, but this is an incorrect subsequent spelling (Anischenko in litt.).

A second genus in the tribe is Cypholoba, represented here by C. alveolata. As far as I can tell it lacks a common name, which is not surprising since it is somewhat smaller than the Anthia species mentioned above. Still, my two specimens measure 38 and 35 mm in length – not puny by any standard. There can be no doubt as to the origin of the specific epithet of this species’ scientific name, with its marvelously alveolate elytra. I don’t think I’ve seen such an extraordinary example of this type of surface sculpturing on a beetle of this size, making the species every bit as spectacular as the larger anthiines.

A truly fascinating aspect of Africa’s tyrant ground beetles is their role as models in Batesian mimicry systems. That these beetles should serve as models is not at all surprising due to their chemical defensive capabilities and obviously aposematic coloration. What is surprising is the mimic – juveniles of the lizard species, Eremias lugubris, in what is believed to be the first reported case of a terrestrial vertebrate mimicking an invertebrate (Huey & Pianka 1977). The juveniles not only copy (roughly) the black and white coloration of anthiine beetles but also mimic their rapid, skitty movements – foraging actively with “jerky” motions and arched backs. Their tails remain somber colored, however, allowing them to blend into the sand. These adaptations combine to give the harmless little lizard the size, color, profile, and gait of the beetles. As the lizards reach adulthood (and their greater size makes them less prone to predation), they take on a more typical cryptic coloration and move in a slower, more deliberately lizard-like manner. This mimicry association effectively reduces predation of the juveniles by potential predators, who quickly learn to avoid the noxious, and more frequently encountered, anthiine models.

REFERENCES:

Beutela, R. G., I. Riberab and O. R. P. Bininda-Emonds. 2008. A genus-level supertree of Adephaga (Coleoptera). Organisms, Diversity & Evolution, 7:255–269.

Huey, R. B. and B. R. Pianka. 1977. Natural selection for juvenile lizards mimicking noxious beetles. Science, 195 (4274):201-203.

Picker, M., C. Griffiths and A. Weaving. 2002. Field Guide to Insects of South Africa. Struik Publishers, Cape Town, 444 pp.

Scholtz, C. H. and E. Holm (eds.). 1985. Insects of Southern Africa. Butterworths, Durbin, 502 pp.

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Beetles In The Bush

Experiences and reflections of a Missouri entomologist

mimicry

Mylabris oculatus in South Africa

Euhagena nebraskae in Kansas

Monday Moth: White-tipped Black Moth

Ospriocerus abdominalis

Pyromorpha dimidiata

Bizarre, beautiful extremes

Tragidion confusion

Tyrant ground beetles

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