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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Friday Flower: Red Buckeye

Beetles, spiders, and snakes were not the only delights that Rich and I saw as we hiked the lower stretch of the Ozark Trail’s Wappapello Section in early April.  Entering the rich, moist, east-facing slopes overlooking the Black River valley, the oaks and hickories were still in the early stages of bud break. A lush, green understory, however, spread out before us, punctuated by the striking inflorescences of red buckeye, Aesculus pavia (family Hippocastanaceae). Among the first trees to bloom in spring, red buckeye is unmistakable in the field due to its red flowers and palmately divided leaves.

Red buckeye is native to the southeastern U.S., just reaching Missouri in the southeastern Ozarks (though cultivated further north). This makes it less well-known than the more widely distributed Ohio buckeye, Aesculus glabra (absent only from the southeastern lowlands and northwestern corner of the state, and easily distinguished by its white inflorescences, larger size, and spreading growth habit).  Like that species, the seeds and young foliage especially are poisonous if eaten due to glycosidic alkaloids and saponins.  Native Americans roasted, peeled and mashed the nuts into a meal called “Hetuck.”

I first encountered this species in 2001 along Fox Creek in the White River Hills of extreme southwestern Missouri.  It was one of several species that I had selectively “cut” and left in situ for a season to allow infestation by wood boring beetles.  I retrieved the wood the following spring and reared five species of longhorned beetles (family Cerambycidae) from the dead branches, including Astyleiopus variegatus, Hyperplatys maculata, Leptostylus transversus, Lepturges angulatus, and the prize – the very uncommonly encountered Lepturges regularis. All of these represented new larval host records; however, it was not until after I published those records (MacRae and Rice 2007) that I realized the plant itself was not known by Steyermark (1963) to occur naturally outside of the southeastern Ozark Highlands.

Speaking of early spring flowers, many such delights can be found at Berry Go Round #27 which is now up at Mary Farmer’s A Neotropical Savanna. It’s not just spring ephemerals, however, as another Missouri blogger and I show that winter has it’s own botanical charms. Stop by and enjoy the feast!

REFERENCES:

MacRae, T. C. and M. E. Rice. 2007. Distributional and biological observations on North American Cerambycidae (Coleoptera). The Coleopterists Bulletin 61(2):227–263.

Steyermark, J. A. 1963. Flora of Missouri.  The Iowa State University Press, Ames, 1728 pp.

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: Arniocera erythropyga

Arniocera erythropyga (Zygaenidae), Geelhoutbosch, South Africa

Last week’s king cricket quiz (Tuesday Teaser) reminded me that I still have quite a few photographs from my trip to South Africa, now 10 years ago, that I still haven’t shared. This pretty little moth is Arniocera erythropyga, which I photographed at Geelhoutbosch farm in South Africa’s Northern (now Limpopo) Province while clambering up the magnificent north-facing escarpment of the Waterberg Mountains. 

I saw this moth as it sat on the foliage of Grewia sp. (family Malvaceae) – fully exposed for all the world to see.  If we’ve learned anything by now, we know that brightly colored insects that expose themselves conspicuously during the day are probably protected by chemical defences (or perhaps mimicking something that is). Such was the case for Bromophila caffra, an equally strikingly-colored fly that I saw on the same hike, and it is also the case for this moth as well. Arniocera erythropgya is a member of the family Zygaenidae, or burnet moths – many members of which are known to release hydrogen cyanide (Scholtz and Holm 1985). This is the same family to which another toxic species I featured last spring belongs (Pyromorpha dimidiata).  A number of moths and butterflies in other families are also known to release HCN (produced by the breakdown of cyanoglucosides sequestered from the plants on which they feed); however, all life stages of zygaenid moths, including the egg, contain these compounds.  This suggests that zygaenid species are capable of synthesizing these compounds themselves rather than needing to sequester them from their host plants (Scoble 1992). While some zygaenid larvae do feed on plants that contain cyanoglucosides, they apparently do so simply because of their tolerance to the compounds but without the need to sequester them from the plant.

Thus, when I saw and approached this little moth, it didn’t flinch or flee.  Protected by toxicity, it continued sitting brazenly atop its exposed perch – welcoming me to see it, daring me to do anything more than take its photo.

My thanks to Roy Goff at African Moths for confirming the identity of the individual in this photograph.

REFERENCES:

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

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

Copyright © Ted C. MacRae 2010.

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Pyromorpha dimidiata

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

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.

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Answers to “Winter botany quiz #2”

Finally, I present to you the answers to “Winter botany quiz #2 “. The delay in providing these answers was two-fold. Firstly, I knew this would be a hard test, so I wanted to give people plenty of time to figure out the answers. Secondly, the answers were delayed an extra day due because of some debate that arose among the experts I consulted about #3 – more on that below. I thank all those who participated, and while there was no clear-cut “winner”, several honorable mentions are deserved:

  • Doug Taron, who was the first to properly deduce the South African nature of these plants.
  • James C. Trager, a myrmecologist (yet still my friend!) who correctly identified the genus of #1.
  • Everyone, for guessing that #2 was “an orchid” – although Tom @ Ohio Nature was the only one to use the formal scientific name for the family, and Doug Taron was the only one to attempt a generic identification (and came close – Oncidium and Ansellia are both assigned to the tribe Cymbidieae in the subfamily Epidendroideae).

#1.  Ornithogalum seineri (family Hyacinthaceae)
Ornithogalum is a large genus occurring mostly in the drier habitats of southern Africa and around the Mediterranean.  The genus and its relatives were formerly included in the Liliaceae (as many of the participants guessed), but the group is now given familial status as the Hyacinthaceae.  This genus contains numerous species of horticultural note.  One is (as James noted) O. umbellatum, or  “star of Bethlehem”, which in North America has escaped cultivation as a garden ornamental and gained status as an invasive weed.  Another is O. longibracteatum (syn. caudatum), a popular houseplant with the common name “pregnant onion”.  This species, native to the Cape and Natal Provinces of South Africa, is easily recognized by its bulb that “gives birth” to tiny replicas of itself just beneath a thin, transparent ‘onion’ skin (as shown in the photo at right from Trans-Pacific Nursery).  At flowering, a long spike grows from the center of the green strap leaves, eventually giving rise to a spearhead of tiny white flowers situated at the end.

While I couldn’t find much information about O. seineri, I did find this spectacular photo of numerous blooming plants in bushveld habitat amongst grazing zebra (photo by ingrid1968 in this post at SANParks.org Forum).  My view of this species was not quite so spectacular, as I saw only the lone plant in the photographs posted earlier.

#2.  Ansellia africana (family Orchidaceae)
Ansellia is an African genus of orchid commonly called Leopard Orchid or African Ansellia.  There is some degree of morphological, geographical and ecological variation in Ansellia populations, with the result that several species, subspecies and varieties have been described.  Flower color varies from pure yellow to variably splotched with brown to almost completely black with finely indicated yellow divisions.  Recent taxonomic work has concluded that there are no discontinuities within the spectra of variations exhibited and the populations are thus attributable to the single, polytopic species, A. africana (Khayota 1999).

Ansellia africana is a large, perennial, epiphytic species that usually grows attached to the branches of tall trees but is sometimes found growing on rocks.  This genus is immediately recognizable by its large, cane-like pseudobulbs that arise from a basal rhizome and is notable for the white, needle-like, upward pointing aerial roots that form a sort of “trash basket” around the clump.  The term is surprisingly appropriate, since the root basket seems to function in catching dropping leaves, flowers and detritus which provide nutrients for the plant as they decay.  This species can grow to enormous size and often forms spectacular clumps, some of which have an estimated weight of more than one ton.

Of the three plants featured in the quiz, this was the one I expected someone would guess, since the species is popularly cultivated by orchid enthusiasts.  Unfortunately, the pressures of wild collection for commercial purposes has caused declines in its population.  The problem is exacerbated by the unsustainable methods use to harvest, transport, and cultivate wild-born plants.  Host trees are usually cut down and sections with the orchid removed, resulting in wholesale destruction of both orchids and hosts. After harvesting, plants are cut up and transported slowly in open handcarts, to be sold along roadsides where they may sit exposed to full sun for days or weeks.  Cutting the clumps damages the roots, and exposure results in dessication, making it difficult for harvested plants to recover once in cultivation.  Plants that do survive harvest and transplant suffer high mortality rates in cultivation due to improper attention to light and moisture regimes.

#3. Adenia sp., poss. glauca (family Passifloraceae)
To be completely honest, not only did I not expect anyone to guess this one, I didn’t think I was even going to be able to provide an answer. I sent the photos to my friend and colleague, George Yatskievych, director of the Flora of Missouri Project (and author of the recently published Steyermark’s Flora of Missouri, 1999 and 2006), who forwarded the photographs to several more colleagues, and at the same time I posted the photos on SANParks.org Forum (a fantastic resource, which I just recently discovered myself, for those interested in South Africa National Parks and their natural history). It took some time for these sources to weigh in with their opinion, which in the end were in agreement that it represented a species of African passion flower in the genus Adenia of the family Passifloraceae (not to be confused with Adenium, a genus of flowering plants in the family Apocynaceae – also occurring in Africa). As for which species, the choices had been narrowed down to either A. glauca or A. fruticosa. According to Imberbe, a photo of the leaves would have been diagnostic, and the flowers are also different (A. glauca has yellow flowers while those of A. fruticosa are green). Fred Dortort, in an article on the University of California at Berkely Botanical Garden website titled, “Passion and Poison“, notes that A. fruticosa has a tall, spindle-shaped caudex topped with a few thin, sparsely-leafed, arching branches, while in A. glauca the caudex is roughly globose and can become quite large. This description seems to favor A. glauca, which Imberbe also noted was known to occur in the area where I took the photographs.

Species identification aside, the genus Adenia is notable for its bizarre adaptations for water storage. Most of the 100 or so species in this Afrotropical and Indomalaysian genus have underground tubers. Those of species adapted to drier environments have grown proportionately larger, with some turning into above ground caudices that can take several different forms and that, in some species, may reach up to eight feet in diameter and height. Even more notable than these succulent adaptations are the poisonous properties that many plants in the genus possess. Not all species have been analyzed (and I found little or conflicting information about A. glauca and A. fruticosa), but one species in the genus – A. digitata – has gained notoriety as perhaps the most poisonous plant in the world. Two different toxins are found within its tuber, one a cyanogenic glycoside, the other a particularly potent toxin called modeccin. The latter is a 57kD protein that resembles ricin and acts a powerful inhibitor of protein synthesis by binding to ribosomes (Gasperi-Campani et al. 1978). Imberbe, in her comments about the photos I posted on SANParks.org Forum, noted the following about plants in this group:

…take heed of the Afrikaans name “Bobbejaangif” (Baboon poison)… It has been used as a fish poison, as well as in suicide and murder. It causes nausea, fits and liver and kidney damage.

REFERENCES:

Gasperi-Campani, A., L. Barbieri, E. Lorenzoni, L. Montanaro, S. Sperti, E. Bonetti, & F. Stirpe. 1978. Modeccin, the toxin of Adenia digitata. Biochemistry Journal 174:491-496.

Khayota, B. N. 1999. Notes on systematics, ecology and conservation of Ansellia (Orchidaceae), pp. 423-425. In: J. Timberlake & S. Kativu (eds.), African Plants: Biodiversity, Taxonomy and Uses, Royal Botanic Gardens, Kew.

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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Millipede assassin bug

Ectrichodia crux

I continue the hemipteran theme begun in the last post with this photograph I took in South Africa below the Waterberg Range in Northern (now Limpopo) Province. I recognized them as members of the family Reduviidae (assassin bugs), and since to my knowledge species in this family are exclusively predaceous (except for the so-called “kissing bugs” of the mostly Neotropical subfamily Triatominae, large distinctive bugs that feed exclusively on vertebrate blood), I found what I took to be a case of scavenging on a dead millipede to be rather curious.  It had rained the previous evening, resulting in a burst of millipede (and insect) activity that night, and this scene was rather commonly encountered the following morning. Of course, appearances can be deceiving, and it turns out that I actually was witnessing predation – and a most unusual case at that.  The individuals in this photo represent Ectrichodia crux (millipede assassin bug), a common species in many parts of southern Africa.  Although nearly 500 species of assassin bugs are known from the region (Reavell 2000), E. crux is easily recognizable due to its large size (adults measure up to 22 mm in length), stout form, and coloration – shiny black, with a distinctive black cross incised on its dull yellow thorax and with yellow abdominal margins (Picker et al. 2002). The nymphs as well are distinctive – bright red with black wing pads. Clearly, these insects are advertising something.

Ectrichodia crux belongs to the subfamily Ectrichodiinae, noted for their aposematic coloration – often red or yellow and black or metallic blue, and as specialist predators of Diplopoda (Heteropteran Systematics Lab @ UCR).  Species in this subfamily are most commonly found in leaf litter, hiding during the day under stones or amongst debris and leaving their shelters at night in search of millipedes (Scholtz and Holm 1985). They are ambush predators that slowly approach their prey before quickly grabbing the millipede and piercing the body with their proboscis, or “beak.”  Saliva containing paralytic toxins and cytolytic enzymes is injected into the body of the millipede to subdue the prey and initiate digestion of the body contents, which are then imbibed by the gregariously feeding assassin bugs.

Millipedes employ powerful chemical defenses – primarily benzoquinones and sometimes hydrogen cyanide gas as well, which are discharged from specialized glands along the millipede’s body – to protect themselves from predation.  Thus, specialized predation of millipedes is a niche that has been exploited by relatively few predators, and little is known about the mechanisms used for circumventing these defenses. The recently reported millipede specialist, Deltochilum valgum (order Coleoptera, family Scarabaeidae), has been observed killing its prey by violently decapitating and disarticulating it before feeding on the body contents (Larsen et al. 2009, summary here); however, the exact manner by which the beetle avoids or withstands the millipede’s chemical discharges remains unknown.  For ambush predators such as Ectrichodia crux and other ectrichodiines, a strategy similar to that described for another millipede specialist predator, larvae of the phengodid beetle, Phengodes laticollis (order Coleoptera, family Phengodidae), might be employed. This species subdues its millipede prey by piercing thinner regions of the millipede’s integument (e.g., intersegmental membranes on the ventral surface) with its hollow sickle-shaped mandibles and apparently injecting gastric fluids that abruptly paralyze the millipede, thereby preventing it from discharging its gland contents (Eisner et al. 1998).  These undischarged benzoquinones remain confined to the glands and are prevented from diffusing into the body cavity by the glands’ impervious cuticular lining, thus allowing the phengodid larva to safely imbibe the liquified systemic contents of the immobilized millipede.

REFERENCES:

Eisner, T., M. Eisner, A. B. Attygalle, M. Deyrup and J. Meinwald. 1998. Rendering the inedible edible: Circumvention of a millipede’s chemical defense by a predaceous beetle larva (Phengodidae).  Proceedings of the National Academy of Sciences USA 95(3):1108–1113.

Larsen, T. H., A. Lopera, A. Forsyth and F. Génier. 2009. From coprophagy to predation: a dung beetle that kills millipedes. Biology Letters DOI:10.1098/rsbl.2008.0654.

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

Reavell, P. E. 2000. The assassinbugs (Hemiptera: Reduviidae) of South Africa. http://oldwww.ru.ac.za/academic/departments/zooento/Martin/reduviidae.html#ectrichodiinae.

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

Copyright © Ted C. MacRae 2009

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