Desmocerus palliatus – elderberry borer

Desmocerus palliatus (elderberry borer), Squaw Creek Natl. Wildlife Refuge, Missouri.

Last June I made two trips to the Loess Hills in northwestern Missouri to survey additional sites for Cylindera celeripes (swift tiger beetle), which my colleague Chris Brown and I had discovered in some of the area’s few remaining loess hilltop prairie remnants the previous year. One of these potential new sites was  Squaw Creek National Wildlife Refuge, where a few tiny slivers of hilltop prairie can still be found on the fingers of loess bluffs that border the refuge’s several thousand acres of restored wetlands that famously host large concentrations of snow geese and bald eagles during the fall and spring migrations.  On the first visit, I had arranged to meet with Corey Kudrna, Refuge Operations Specialist, who was kind enough to take several hours out of his day to personally guide me to each of the site’s loess hilltop prairie remnants. 

As we crossed the highway right-of-way at the base of the bluffs on our way to the one of the remnants, we passed through a large patch of common elderberry, Sambucus nigra ssp. canadensis.  Anytime I see patches of this plant, especially in June, I immediately think of Desmocerus palliatus (elderberry borer) – a spectacularly colored longhorned beetle (family Cerambycidae) that breeds exclusively in the living stems and roots of this plant.  It is not a particularly rare species, but for some reason I have not had much success in finding this species.  In my close to three decades of collecting beetles, I had encountered perhaps a half dozen individuals – never more than two at the same time.  Still, when I get the chance to look at elderberry I look for this beetle, and when I did so this time I was delighted to see one within a few moments of entering the patch.  I was ecstatic when I saw another one almost immediately after the first, and I was stunned when I realized that they were all around me!  Good fortune continued on my subsequent visit two weeks later, when I was able to spend a little more time trying to get a good field photograph.  Wind was a problem, the beetles were easily alarmed, and their tendency to rest in the upper reaches of the plant made it difficult to brace myself and the camera while shooting, making this a rather difficult subject to get a good photograph of.  The photo shown here is literally the last of around two dozen that I took and is the only one that I really like.

Many cerambycid beetles are mimics of other more noxious species, mostly ants and wasps.  However, elderberry borers appear to be the exception in that they are themselves noxious.  The cobalt blue and bright orange coloration of the adults screams aposematic (warning) coloration, and it is reasonable to assume that they accumulate in their bodies for defensive purposes the cyanogenic glucosides produced by elderberry plants (Huxel 2000).  Even their movements are those of a chemically protected model – lumbering and clumsy, without the alert evasiveness usually seen with other flower longhorn species.  Presumably this species participates in a Müllerian mimicry complex involving netwinged beetles (family Lycidae, particularly species in the genus Calopteron) and perhaps Pyromorpha dimidiata (orange-patched smoky moth, family Zygaenidae) as well, and it may serve as a Batesian model for the equally colorful but completely innocuous Lycomorpha pholus (black-and-yellow lichen moth, family Arctiidae).

Photo Details: Canon 50D w/ 100mm macro lens (ISO 100, 1/250 sec, f/10), Canon MT-24EX flash w/ Sto-Fen diffusers.

REFERENCE:

Huxel, G. R.  2000.  The effect of the Argentine ant on the threatened valley elderberry longhorn beetle.  Biological Invasions 2:81–85.

Copyright © Ted C. MacRae 2010

Phreaky Phalangid

While searching through shortgrass prairie atop the Pine Ridge in northwestern Nebraska in hopes of finding Cicindela nebraskana (prairie long-lipped tiger beetle), this harvestman caught my eye.  Harvestmen are, of course, arachnids related to spiders, but they lack fangs and poison or silk glands and are placed the separate order Opiliones (Phalangida when I was in school).  Admittedly, I haven’t paid much attention to harvestmen before now, but this one seemed different from any I’d seen before – nearly black with relatively short legs and distinctive orange intersegmental articular membranes at the base of the legs.  Harvestmen are known to employ chemical defenses through special repugnatorial glands that produce phenols, quinones, ketones, and/or alcohols, and this individual seemed to display a clear example of aposematic coloration to warn any potential predators of its distastefulness.

Trachyrhinus favosusAlthough beetles are my focus, I normally try to do my own identifications in other groups as well.  However, some rather persistent searching through the extensive harvestman holdings at BugGuide failed to turn up a good match.  In gestalt it seemed to belong to the family Sclerosomatidae, but even that was just guessing on my part.  So, I did what I’ve done only a few times before and posted the photos to BugGuide’s ID Request.  A day and a half later I had my answer – Trachyrhinus favosus.  BugGuide Contributing Editor V. Belov had sent the photos to harvestman expert Marshal Hedin, who had this to say in response:

Cokendolpher describes males as ‘body ranging from solid black…’ with bases of femora ‘yellow-brown’. The species is also known from western Nebraska. Cool.

I was pleased to learn that these photographs represented a new species for BugGuide and no longer felt bad about not being able to find a good match.  Further, my leanings toward the family Sclerosomatidae had been confirmed.  According the Cokendolpher (1981), T. favosus ranges in a narrow band from North Dakota south to north-central Texas and is active only during fall.  I had intended to try to get an even closer photograph, but after taking the second photograph above I accidentally disturbed the critter and then watched in amazement as it began bouncing up and down vigorously.  This apparently is a defensive behavior that functions to blur the body form.  I watched it bounce and became even more amazed as it began calmly walking away while continuing its vigorous bouncing – quite a spectacle!

Photo Details: Canon 50D w/ MP-E 65mm 1-5X macro lens (ISO 100, 1/250 sec, f/13), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCE

Cokendolpher, J. C.  1981. Revision of the genus Trachyrhinus Weed (Opiliones, Phalangioidea).  Journal of Arachnology 9:1–18.

Copyright © Ted C. MacRae 2010

North America’s largest centipede

As I prowled the remote mixed-grass prairie of northwestern Oklahoma in the middle of the night, an enormous, serpentine figure emerged frenetically from a clump of grass and clambered up the banks of the draw I was exploring.  Although I was still hoping for my first glimpse of the Great Plains giant tiger beetle, I was keeping a watchful eye out for anything that moved within the illuminated tunnel of my headlamp due to the potential for encountering prairie rattlesnakes (perhaps the most aggressive of North America’s species).  This was clearly no snake, but at up to 8″, Scolopendra heros (giant desert centipede) easily matches some smaller snakes in length.  Also called the giant Sonoran centipede and the giant North American centipede, it is North America’s largest representative of this class of arthropods (although consider its South American relative, S. gigantea – the Peruvian or Amazonian giant centipede, whose lengths of up to 12″ make it the largest centipede in the world).

Although I had never before seen this species alive, I recognized it instantly for what it was.  Many years ago I was scouting the extreme southwest corner of Missouri for stands of soapberry (Sapindus saponaria), a small tree that just sneaks inside Missouri at the northeasternmost limit of its distribution, in hopes of finding dead branches that might be infested with jewel beetles normally found in Texas.  I had heard that these centipedes also reach their northeastern extent in southwestern Missouri, and just a few miles from the Arkansas and Oklahoma borders I found a road-killed specimen.  I stood there dejected looking at it – too flattened to even try to salvage for the record.

Centipedes, of course, comprise the class Chilopoda, which is divided into four orders.  The giant centipedes (21 species native to North America) are placed in the order Scolopendromorpha, distinguished by having 21 or 23 pairs of legs and (usually) four small, individual ocelli on each side of the head (best seen in bottom photo).  The three other orders of centipedes either lack eyes (Geophilomorpha) or possess compound eyes (Scutigeromorpha and Lithobiomorpha).  These latter two orders also have only 15 pairs of legs (shouldn’t they thus be called “quindecipedes”?).  Among the scolopendromorphs, S. heros is easily distinguished by its very large size and distinctive coloration.  This coloration varies greatly across its range, resulting in the designation of three (likely taxonomically meaningless) subspecies.  This individual would be considered S. h. castaneiceps (red-headed centipede) due to its black trunk with the head and first few trunk segments red and the legs yellow.  As we have noted before, such striking coloration of black and yellow or red nearly always indicates an aposematic or warning function for a species possessing effective antipredatory capabilities – in this case a toxic and very painful bite.

The individual in these photographs is not the first one I saw that night, but the second.  I had no container on hand to hold the first one and not even any forceps with which to handle it – I had to watch in frustration as it clambered up the side of the draw and disappear into the darkness of the night.  Only after I returned to the truck to retrieve a small, plastic terrarium (to fill with dirt for the giant tiger beetles that I now possessed) did I luck into seeing a second individual, which I coaxed carefully into the container.  It almost escaped me yet again – I left the container on the kitchen table when I returned home, only to find the container knocked onto the floor the next morning and the lid askew.  I figured the centipede was long gone and hoped that whichever of our three cats that knocked the container off the table didn’t experience its painful bite.  That evening, I noticed all three cats sitting in a semi-circle, staring at a paper shredder kept up against the wall in the kitchen.  I knew immediately what had so captured their interest and peeked behind the shredder to see the centipede pressed up against the wall. The centipede had lost one of its terminal legs but seemed otherwise none the worse for wear – its terrarium now sits safely in my cat-free office, and every few days it enjoys a nice, fat Manduca larva for lunch.

There are a number of online “fact sheets” on this species, mostly regarding care in captivity for this uncommon but desirable species.  I highly recommend this one by Jeffrey K. Barnes of the University of Arkansas for its comprehensiveness and science-focus.

Photo Details: Canon 50D (ISO 100, 1/250 sec) w/ Canon MT-24EX flash in white box.
Photos 1-2: Canon 100mm macro lens (f22), indirect flash.
Photo 3: Canon MP-E 65mm 1-5X macro lens (f/13), direct flash w/ Sto-Fen + GFPuffer diffusers.
Post-processing: levels, minor cropping, unsharp mask.

Copyright © Ted C. MacRae 2010

The Moth and Me #11

The Moth and MeWelcome to issue #11 of The Moth and Me, the monthly carnival devoted to the “forgotten” lepidopterans. Most people – even entomologists – regard these as the lesser leps, denizens of the night, as if to hide their somber-colored drabness from the flashy brilliance of their rhopaloceran relatives. Of course, this simply isn’t true, as the contributions to this month’s issue well demonstrate. Butterflies may be among the largest insects on earth, but the largest lepidopteran in the world is a moth. They may also be as gaudily colored as the rainbow itself, but what butterfly is more colorful than the Urania day-flying moths (the genus name literally means, “The heavenly one”).   And, they may be almost universally accepted by a largely insect-indifferent public, but who among us does not think back to that first sight of a luna moth as the most stunning insect we had ever seen to that point.  Yes, moths are all that butterflies are, and for this month’s issue of TMaM, 15 contributions by nine writer’s show us why.

Family Saturniidae – Giant Silkworm & Royal Moths

Tales from the Butterfly Garden: LepcuriousLuna moths belong to the royal moths of the family Saturniidae, and as the name implies they are not the only stunningly beautiful member of the group. Kristen at Tales from the Butterfly Garden: Lepcurious writes about an encounter with the Sweetbay Silkmoth (Callosamia securifera).  Like other members of the family, larvae of this species are rather particular about the type of tree that they utilize for food, which in the case of this moth is sweetbay (Magnolia virginiana).  I’m a little too far north here in Missouri for this tree, so I have never seen this moth.  However, I have seen (and reared) some of its close relatives, the Promethia Silkmoth (Callosamia promethea) which hosts on several plant species and the Tulip-tree Silkmoth (Callosamia angulifera) which hosts on Tulip Tree (Liliodendron tulipifera).

Family Zygaenidae – Leaf Skeletonizer Moths

xenogereJason Hogle at xenogere is fond of the unusual and has a gift for finding it. In his post The Unmoth, Jason shows us a male grapeleaf skeletonizer (Harrisina americana) – not your typical moth!, The uniformly black color and bright red neck collar just screams “Don’t eat me – I’m poisonous”, and indeed species in this family are among the few insects capable of producing hydrogen cyanide!  As the name suggests, larvae skeletonize the leaves of both wild and cultivated grapes (Vitis spp.), as well as the related Virginia creeper (Parthenocissus quinquefolia).

Family Noctuidae – Noctuid Moths & Tiger Moths

Tales from the Butterfly Garden: LepcuriousRoyal moths are not the only stunningly colored moths that Kristen at Tales from the Butterfly Garden: Lepcurious has found in Florida, as she shows in this post on Oleander Moths (Syntomeida epilais) and a companion piece on its Oleander host plant.  This striking day-active moth, also called Uncle Sam Moth (for its red, white, and blue colors) and Polka-Dot Wasp Moth (for obvious reasons), may seem like an easy-to-spot target for would be predators, but its gaudiness is actually warning of the toxic chemicals it has sequestered in its body from the Oleander on which it fed as a larva.  Oleander contains the toxins oleandrin, a cardiac glycoside, and neandrin and is toxic if ingested.  Although oleander is an Old World exotic, oleander moths may also be found feeding on devil’s potato vine (Echites umbellata), which may have been their native Florida host before the introduction of oleander to the United States.

See TrailAside from the underwings (genus Catacola) and the recently incorporated tiger moths, Noctuids are typically thought of as the “basic brown moths” – relying on just the aforementioned groups to add a splash of color to the family’s otherwise drearyness.  Nothing could be further from the truth – check out the stunning Eight-spotted Forester (Alypia octomaculata) in this post by Matthew York at See Trail. Larvae of this beautiful little moth feed on ampelopsis, Virginia creeper, and other plants in the grape family (similar to the grape leaf skeletonizer above). “A great moth; brilliant color, diurnal…… and yes… Noctuid. Some moths, like people, don’t go with the trends.”

See TrailFor the most part, tiger moths shun the daytime in preference for the safety of the night. That does not mean, however, that they are any less colorful, as Matthew York at See Trail shows in his post Poor Grammia. Notarctia proxima, the Mexican Tiger Moth, and its relatives have had a bit of name shuffling over the years at the hands of taxonomists – formerly placed in the genera Grammia and Apantesis. Whatever name you call it, the striking white and black striped forewings give a clue about their common name of tiger moths, and the red, black-tipped abdomen not only add to its beauty, but belies the defensive compounds it surely contains.

Speaking of tiger moths and defensive compounds, watch the video that Chris Grinter at The Skeptical Moth included in his post Moth Perfume. In it, Chetone angulosa gives a striking display of a common defensive mechanism for the group – excreting hemolymph (sweating blood, so to speak!). So spectacularly does the moth do this that you can actually hear the hissing sound of the fluid being pumped from the body. Moreover, there seem to be at least a couple of active ingredients in the froth – one that smells like peppermint, and another that causes numbing of the tongue (as Chris can testify firsthand – he is a truly dedicated experimental naturalist!).

Karthik's JournalIn similar fashion to our North American species of underwing moths (Catocola spp.), the related Eudocima materna, one of the fruit-sucking moths of south India, uses its drab-colored forewings to hide its brilliantly colored hindwings, as Karthik at Karthik’s Journal shows us in his post Startling Displays.  This forms a double line of defense against would-be predators – the forewings blend marvelously into the color of the tree trunks upon which it rests during the day, camouflaging the insect and making it nearly invisible.  If this doesn’t work, a sudden flash of the hindwings may startle the predator just enough to allow the moth to take flight to another tree – where it instantly “disappears” as soon as it closes its wings.

Snails Eye ViewAustralia also has some very colorful fruit-piercing moths, and Bronwen Scott at Snails Eye View presents some beautiful photos of the particularly strikingly-colored Othreis iridescens. Like other members of the group, this Far North Queensland endemic feeds on fruit (Pycnarrhena novoguineensis and Hypserpa laurina, both Menispermaceae, in the case of this species), but as it is apparently the rarest of the primary fruitpiercing moth species in Australia it is not considered to be a pest (and Bronwen would cut it some slack even if it was!).

EntophileAdults are but only one of four life stages that all moths go through. If moths are the “forgotten” leps, then caterpillars are the “forgotten” moths. In many cases, the caterpillar stage cannot be recognized until it becomes a moth (and in some cases the caterpillars are completely unknown). Fortunately, Navy entomologist corycampora at Entophile recognized the caterpillar he found on his croton bush, which he features in the post Croton caterpillar, Achaea janata (Linnaeus), (Lepidoptera: Noctuidae). These “eating machines” can be just as fascinating to observe as their scaled adult counterparts, and while croton seems to be a preferred host in Hawaii, it apparently also feeds on castor beans (judging by its other common name, Castor Oil Semi-looper).

Family Notodontidae – Prominent Moths

the Marvelous in NatureOften dismissed as noctuids, the prominent moths tend to be fuzzier, more thickly-bodied moths that rest with their wings curled around their abdomen or tented over their back (rather than flat like noctuids and most other moths). TMaM organizer Seabrooke Leckie at the Marvelous in Nature has a love affair with prominents, and in her post Georgian Prominent, she features the nicely thick-bodied and fuzzy Georgian Prominent, Hyperaeschra georgica. The caterpillars of this widespread species feed on oak (Quercus spp.), thus, unless you live in the Pacific Northwest you stand a good chance of encountering this species – if you’re you’re willing to make the effort.

Family Psychidae – Bagworm Moths

xenogereMany of us are probably familiar with the evergreen bagworm moth (Thyridopteryx ephemeraeformis), whose large, cone-shaped bags almost look like fruit hanging from the evergreen bushes on which the caterpillars feed. But did you know there are other species of bagworms as well? Jason Hogle at xenogere does, and he compares and contrasts two of them in this duo of posts, Rainy day on the patio and The Other Bagworm. One huge and prominent, the other (Dahlica triquetrella) very small and oft unseen. One with all manner of plant matter stuck to its bag, the other usually mistaken for small bits of dirt or wood. Jason is so good, he can even determine the sex of the caterpillar inside the bag!

Family Sphingidae – Hawk Moths

Roundtop RumingsCarolyn at Roundtop Rumings is hoping that somebody can Name this moth, which she found on the door of her cabin in the forests of Pennsylvania. Don’t let her inability to name this moth fool you, however, for her post contains loads of information on exactly the kinds of characters one should take note of when trying to identify hawk moths. Large size and membership in a popularly studied group aren’t enough – what do the hindwings look like? Are there any spots on the abdomen? As a coleopterist, I hesitate to offer my relatively uninformed opinion on the exact genus and species for this moth, but I’m going to go out on a limb here and suggest maybe something in the genus Ceratomia, perhaps the waved sphinx (C. undulosa)?


I hope you have enjoyed this issue of The Moth and Me, and my sincere thanks go out to all of those who contributed!  The hosting slot for next month’s issue of TMaM is still open, but you can submit your contributions anyway to Seabrooke Leckie at the home site for inclusion in the June 2010 issue once a host is selected.  The submission deadline is June 13, with the issue appearing a few days later.  Perhaps you might like to host the June issue – hosting is not only fun, but also a great way to introduce readers to your site and generate a little traffic.  Contact Seabrooke at the home site if you’re interested – I’m sure she would love to hear from you.

Copyright © Ted C. MacRae 2010

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Monday Moth – Trichaeta pterophorina

 Trichaeta pterophorina – Borakalalo National Park, South Africa

Another photo from the South Africa files, and one that continues the mimicry theme that has been featured in several recent posts. It’s not a great photograph – the focus is off – but the colors these moths sport are dazzling, and there is a nice symmetry to their tail-to-tail mating position.

Roy Goff, author of the website African Moths, tells me this species is the Simple Maiden (Amata simplex) in the family Arctiidae (whose ~2,000 species worldwide are increasingly considered a subfamily of the already enormous Noctuidae) [update 6/20/2012—Martin in a comment considers these moths to actually represent Trichaeta pterophorina in the same subfamily].  Its gestalt – greatly resembling a stinging wasp – brings to mind the so-called “wasp moths” of North America (subtribe Euchromiina); however, maidens belong to the exclusively Old World Syntomina.  Like the wasp moths, most maidens are exceptionally colorful and exhibit clearly aposematic patterns.  While these might seem to be textbook examples of Batesian mimicry, most species in this group are also protected by distasteful secondary plant compounds that they sequester through feeding, making them Mullerian rather than Batesian mimics.  These compounds are not only acquired by larvae from their food plants, but also by adult moths who imbibe them from fluid regurgitated through their proboscis onto dried parts of plants containing the compounds and into which they dissolve.

Their aposematism is not limited to strictly visual cues.  An Australian species, Amata annulata, is known to regularly emit ultrasonic clicks when flying, thought to be aposematic behavior to warn bats of its distastefulness in the same way that that its coloration warns daytime predators. Additional defensive characters that have been described for species in the group include frothing and extrusion of defensive processes. Clearly, maidens are leaders in the arms race among the insects!

Copyright © Ted C. MacRae 2010

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Mylabris oculatus in South Africa

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.

Copyright © Ted C. MacRae 2010

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Monday Moth: White-tipped Black Moth

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.

Copyright © Ted C. MacRae 2009

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Magodo – giant twig wilter

petascelis-remipes

In previous posts, I have highlighted some of the insects I observed on a trip to South Africa in November-December 1999.  All of the photos I have shown to this point were taken at Borakalalo National Park in North West Province or at the Geelhoutbos farm of Susan Strauss below the Waterberg Range in the formerly Northern, now Limpopo Province.  Both of these locations are deep inside the bushveld, providing ample opportunity to observe an incredible diversity of insect life.  This is not to say that insects, even spectacular ones, cannot be found in more urban areas.  During the weekend between those two mini-expeditions, I stayed with my friend and colleague, Chuck Bellamy, at his home in Pretoria, a beautiful city with lovely architecture, elegant gardens… and some very impressive bugs!  The bug in this photo was found on a tree in a shrubby enclave, and at well over 35 mm in length it is easily the largest leaf-footed bug (order Hemiptera, family Coreidae) that I have ever seen.  Its chunky build, velvety black coloration with thin yellow lines along the sides and down the center of the thorax, and greatly enlarged hind femora quickly led me to a provisional identification of a male Petascelis remipes, or giant twig wilter.  This ID was confirmed by my friend and colleague Harry Brailovsky, an entomologist at UNAM (Universidad Nacional Autónoma de México) and world expert on Coreidae (and who, incidentally, just recently published a review of this Afrotropical genus – Brailovsky 2008).

According to Picker et al. (2002), these insects are found on plants in the genus Combretum.  Like most species in the family, they have scent (“stink”) glands that provide defensive capabilities. Adults are gregarious and bold, walking towards intruders with antennae vibrating when disturbed, and they are apparently capable of squirting their defensive secretions for some distance.  The nymphs are black as well but futher advertise their noxiousness with warning coloration of red spots on a whitish background. Interestingly, and despite their powerful chemical defenses, this species is considered a delicacy in parts of Mozambique where it is known as Magodo.  In a post called Insects for Dinner (in a blog with the eerily similar title, Beating about the Bush), Bart Wursten of Gorongosa National Park in Mozambique describes how local folk burn small patches of the grassland in which these insects are found to smoke them out and catch them.  The Magodo hunters kill the bugs by breaking off the head and removing the scent glands, which releases a very strong almond-like smell.  In doing this, the locals are able to catch considerable quantities of the bugs, which they eat with supper.

Lest you believe such practices are an anomaly, van Huis (2003) has compiled a list of about 250 insect species used as food in sub-Saharan Africa.  Lepidoptera, Orthoptera and Coleoptera represented the bulk (78%) of species eaten, with Isoptera, Hemiptera, Hymenoptera, Diptera and Odonota making up the rest.  Several examples of toxic insects and the traditional methods used to remove the poisons were given.  It was noted that whether or not insects are eaten depends not only on taste and nutritional value, but also on customs and ethnic preferences or prohibitions.  I’m not one to shy away from the thought of eating insects – after all, shrimp are just bugs that live in water, and insects rank far lower in ‘slime factor’ than many other invertebrates (e.g., oysters) that enjoy great popularity in our culture.  I’ve eaten roasted beet armyworm (Spodoptera exigua) pupae and munched on chocolate covered ants, but that’s kid stuff – the armyworms tasted like the soy sauce in which they were roasted, and the ants tasted like, well… chocolate.  I did once eat a softshelled crab (alive!), and I actually hope to one day taste the enormous grub of the giant metallic ceiba borer, Euchroma gigantea, eaten by indigenous cultures in Central and South America.   Still, I think I’d need a lot of faith in my chef’s scent gland removal prowess before I started scarfing Magodo down like popcorn.

What insects have you eaten?

REFERENCES:

Brailovsky, H.  2008. Notes on the genus Petascelis Signoret and description of one new species (Hemiptera: Heteroptera: Coreidae: Coreinae: Petascelini).  Zootaxa 1749:18–26.

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

van Huis, A. 2003. Insects as food in sub-Saharan Africa. Insect Science and Its Application 23(3):163-185.

Copyright © Ted C. MacRae 2009

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