Desmiphora hirticollis: Crypsis or Mimicry?

During my stay in Corrientes, Argentina last month, I was invited to spend the day with a colleague at his “camp” in Paso de la Patria. Located on the banks of the massive Rio Paraná at its junction with the Rio Paraguay, this small resort community boasts large tracts of relatively intact “Selva Paranaense,” which together with the Atlantic Forest in southeastern Brazil forms the second largest forest ecozone in South America outside of the Amazon. As my colleague skillfully prepared matambre, chorizo, and vacío (typical cuts of meat in Argentina) on the parilla (wood grill) at his camp, I explored the surrounding forest for insects. Early April is late in the season, and with generally droughty conditions in the area for the past several months there were few insects to be found. My luck improved, however, when I came upon a small area with stacks of fresh cut logs from recent wood cutting operations scattered through the area. Wood boring beetles (families Buprestidae and Cerambycidae) are often attracted to such wood piles, so approached each one slowly to look for day-active species of these beetles. After inspecting several piles without seeing anything on them, I began carefully turning over the logs to look for nocturnal species that tend to hide on the undersides during the day. Shortly I came across this highly cryptic species of cerambycid, and further searching revealed a fair number of these beetles hiding within the dozen or so log piles that I examined.

Desmiphora hirticollis on freshly cut guayabi (Patagonia americana) | Corrientes Prov., Argentina

I instantly recognized the genus as Desmiphora, an exclusively New World genus characterized by the presence of fasciculate tufts (or “pencils”) of erect or suberect hairs. Most of its nearly 50 species occur in Brazil, but two species extend as far north as southern Texas (Giesbert 1998). One of these is Desmiphora hirticollis, a widespread species found as far north as Corpus Christi, Texas and as far south as Bolivia and Argentina. I thought these beetles looked an awful lot like that species, and I later confirmed its identity as such due to its piceous (glossy brownish black) integument and the presence of small black pencils just before the elytral apices.

Adults are nearly impossible to see from overhead due to cryptic coloration…

The wood piles contained logs from several tree species, but all of the beetles that I encountered were on logs of guayaibi (Patagonula americana), a member of the family Boraginaceae and a characteristic component of Selva Paranaense (also an important timber species in Argentina). The number of individuals that I found and their occurrence only on guayaibi suggests it serves as a larval host for the beetle. Duffy (1960) described the larva from specimens collected out of Sapium sp. (family Euphorbiaceae), but in Texas this species is collected most often on Cordia spp. and Ehretia anacua (Rice et al. 1985)—both in the family Boraginaceae—with adults having been reared from Cordia eleagnoides (Chemsak & Noguera 1993).

…while the hair tufts may function in obscuring the body outline…

It seems obvious that coloration of the beetle and its pencils of hair function in crypsis. From overhead the beetles are almost impossible to discern as they sit motionless on the similarly colored bark of their host trees. Even in profile or oblique views where the body becomes somewhat more visible, the pencils seem to break up and obscure the outline of the body. I wonder, however, if crypsis is the only function of the pencils—Belt (2004) described the strong resemblance of another species in the genus, D. fasciculata—a similarly penicillate species, to short, thick, hairy caterpillars (insectivorous birds often refuse to prey upon hairy species of caterpillars). That species can be seen sitting openly on foliage during the day, while D. hirticollis seems to be strictly nocturnal; however, cryptic and mimetic functions need not be mutually exclusive, so perhaps for this species the pencils function a little for both.

…or perhaps even mimicking ”hairy” caterpillars.

REFERENCES:

Belt, T. 2004. The Naturalist in Nicaragua. Project Guttenberg eBook.

Chemsak, J. A. & F. A. Noguera.  1993.  Annotated checklist of the Cerambycidae of the Estacion de Biologia Chamela, Jalisco, Mexico (Coleoptera), with descriptions of new genera and species.  Folia Entomológica Mexicana 89:55–102.

Duffy, E. A. J. 1960. A Monograph of the Immature Stages of Neotropical Timber Beetles (Cerambycidae). British Museum of Natural History, London. 327 p.

Giesbert, E. F. 1998. A review of the genus Desmiphora Audinet-Serville (Coleoptera: Cerambycidae: Lamiinae: Desmiphorini) in North America, Mexico and Central America. Occasional Papers of the Consortium Coleopterorum 2(1): 27–43.

Rice, M. E., R. H. Turnbow, Jr. & F. T. Hovore. 1985. Biological and distributional observations on Cerambycidae from the southwestern United States (Coleoptera). The Coleopterists Bulletin 39(1):18–24.

Copyright © Ted C. MacRae 2012

A Modest Model for Mimicry

Spring is still a long way off but it’s times like these that I draw on past experiences so I can continue to be thrilled by insect natural history even during the coldest of months.  In this case I am thinking back seven years ago to my first encounter with a warty leaf beetle.  These beetles are certainly unremarkable for their size or coloration but the “set-up” shot below attempts to illustrate what is amazing about warty leaf beetles.  Can you pick out the single individual warty leaf beetle (Exema sp.) among caterpillar frass (aka caterpillar poop)? 

Figure 1. Set-up shot with Exema sp. and caterpillar frass

If you had trouble finding the beetle in the above image then check out the next image and you’ll see the beetle has “sprouted” a head, legs, and antennae.

Figure 2. Set-up shot with Exema sp. and caterpillar frass

I don’t know what caught my eye the first time I encountered a warty leaf beetle on the foliage of a small shingle oak while exploring a woodland edge in Perry Co., MO.  It probably helped that it was one of the larger species of the genus Neochlamisus but it still only measured about 3-4 mm.  One thing I do remember about the encounter, though, is that there was something about it that made me do a double take.  My first thought was exactly what the beetle might have hoped, that it was caterpillar frass.  But this frass had legs (Figs. 3 and 4)!  I was at first incredulous but soon became enthralled as I beheld something that I had never noted while flipping through field guides.  I had once again stumbled across something that I would never have imagined—a beetle that mimics caterpillar poop!

Figure 3. Neochlamisus sp. on shingle oak

Figure 4. Neochlamisus from the perspective of a short distance away

The beetles in the tribe Chlamasini were apparently not at the table the day decisions were made on what model they would mimic.  These guys at best mimic small bits of debris but are dead ringers for the frass of lepidopteran larvae (i.e., caterpillars).  Then as if to add insult to injury, we dubbed the tribe the warty leaf beetles!  The Chlamasini may humbly mimic excreta but what they lack in a flashy model they make up for with absolutely superb mimicry.  The Chlamasini are remarkably similar to the frass of lepidopteran larvae in size, shape, texture, and color but the aspect that really completes the mimicry is that, upon disturbance, the head is retracted and the legs and antennae are neatly folded into precisely matched grooves leaving no indication that this was once a beetle (Figs. 5 and 6).  Even the finer details of coloration were not overlooked as some warty leaf beetle species are variably colored, including an almost metallic sheen in some places that closely resembles the coloration of some caterpillar frass.  In fact the mimicry of warty leaf beetles is so convincing that I recently dropped a piece of suspect frass in a vial in hopes that it might sprout legs and represent a new species of warty leaf beetle for me.

Figure 5. Exema sp. with appendages extended

Figure 6. Exema sp. with appendages retracted

If the disturbance is sufficient to cause the beetle to completely retract these appendages, they will likely roll off the leaf and fall out of harms way.  Though these beetles can be relatively common, occurring even in my suburban St. Louis yard, the small size [Exema is only 2-3 mm (Figs. 7 and 8) while Neochlamisus is slightly larger at 3-4 mm] and resemblance to something unremarkable ensures that these beetles often times go unnoticed.  When I have happened to notice these beetles I found Neochlamisus associated with shingle oak, Quercus imbricaria, and Exema associated with Asteraceae, including gray-headed coneflower, Ratibida pinnata, and sweet coneflower, Rudbeckia subtomentosa.

Figure 7. Exema sp. on sweet coneflower, Rudbeckia subtomentosa

Figure 8. Exema sp. ready for flight

The Chlamasini are in the subfamily Cryptocephalinae within the leaf beetle family (Chrysomelidae).  The Chlamisini can be found worldwide but are most diverse in the Neotropics.   We have 6 genera in North America, two of which are shown here.  Interestingly, the excreta theme doesn’t stop at frass-mimicry.  Like other members of Crytocephalinae, warty leaf beetle larvae are “case-bearing”; that is they are housed in a case which in this instance is made out of… you guessed it, their own feces (Fig. 9).  You would think that most moms would frown on such a practices but mothers in the Cryptocephalinae actually instigate the practice when they equip each egg laid with a cap of feces that serves as starting material for the case and likely also serves to dissuade would be predators.

Figure 9. Chlamasini larva, likely that of Exema sp. on sweet coneflower, Rudbeckia subtomentosa

My experiences with Neoclamisus seven years ago captures perfectly why I am so drawn to explore for insects— there is always something new to find and every once in a while something comes out of the wood work that is beyond what I could have imagined.

REFERENCE:

Lourdes Chamorro-Lacayo, M. & A. Konstantinov. 2009. Synopsis of warty leaf beetle genera of the world (Coleoptera, Chrysomelidae, Cryptocephalinae, Chlamisini). ZooKeys 8:63–88.

Copyright © Chris Brown 2012

Agelia lordi (Walker)

Aegilia lordi (Walker) | Kenya

This pretty little beetle is Agelia lordi (Walker), a member of the jewel beetle family Buprestidae. I received this meticulously curated specimen – collected in Kenya – in a recent exchange with Stanislav Prepsl (Czech Republic). The species is found in Sub-Saharan east Africa and is the smallest of the nine recognized Agelia species. Two other species occur in eastern and southern Africa, including Agelia petalii (Gory) which I collected in South Africa (see Buppies in the bush(veld)), while the remaining six are found on the Indian subcontinent. The presence of two distinct and geographically isolated population centers, along with some seemingly common differences in the included species, begs the question of whether they may perhaps be subgenerically distinct. Gussmann (2002), however, regarded most of these differences to be simply a matter of degree and insufficient to warrant subgeneric separation.

Males of A. lordi are easily recognized by the orange-brown color of the last 2-3 sterna, in sharp contrast to the mostly strongly metallic integument of the rest of the ventral surface (females and both sexes of all other species have all sterna concolorous). The metallic reflections on the head, pronotal sides, and elytral apices – along with size – further distinguish A. lordi from other African species.

As is typical with so many tropical insects, little is known about the biology and lifestyle of species of Agelia. The bold, contrasting coloration of especially the African species would seem to make them conspicuous to predation, but this seems to be the result of a mimetic association with noxious species of blister beetles (family Meloidae) in the genus Mylabris. I saw one of these (see Mylabris oculatus in South Africa) in association with A. petalii during my 1999 visit to South Africa, and the resemblance was so strong that I had do a double-take every time I saw one to determine whether it was Agelia or Mylabris.

REFERENCE:

Gussmann, S. M. V. 2002. Revision of the genus Agelia Laporte and Gory (Coleoptera: Buprestidae). Annals of the Transvaal Museum 39:23–55.

Copyright © Ted C. MacRae 2011

Monday Moth – Polka-dot Wasp Moth

Syntomeida epilais - polka-dot wasp moth

It’s been a while since I’ve done a Monday Moth post, so I thought I’d feature one of the prettier specimens in my very limited Lepidoptera collection.  This is Syntomeida epilais (polka-dot wasp moth), one of four species in the genus that occurs in the United States.  This particular specimen was collected by me way back in the mid-1980s (I was not quite yet the discriminating beetle collector that I am now) in Everglades National Park (yes, I had a permit).  The bright, contrasting coloration obviously screams aposematism (warning coloration), and in fact the tissues of the adult moths of this species are chock-full of several cardiac glycosides sequestered by the larva from its now preferred food plant, oleander (Nerium oleander).  Add to it their somewhat wasp-like appearance, and there should be no question to any would-be predator that these moths are a bad idea.  Wasp moths are related at the tribal level to another group of wasp-like moths called maidens which are restricted to the Old World.  I featured one of these from South Africa last year in the post, Monday Moth – Simple Maiden (Amata simplex).

If the cardiac gycosides stored in the tissues of this moth aren’t enough to cause gastric distress, trying to digest the higher taxonomic history of this group surely will.  Back in my school days, this moth belonged to the family “Ctenuchidae.”  As best I understand it, this group was later subsumed into the tiger moth family “Arctiidae” – itself later subsumed within the borg of all moth families, the Noctuidae.  In the most recent classification I’ve found, the arctiine moths have been pulled back out of the Noctuidae and combined with the former “Lymantriidae” (propelled to infamy by the gypsy moth) to form the family Erebidae (Lafontaine and Schmidt 2010).  Are you ready to purge yet? It’s still not clear to me whether this latest incarnation represents a consensus monophyletic unit, but it really doesn’t matter – whenever I see wasp moths, maidens, and especially the ctenucha moths that are so common in my area on goldenrod flowers during the fall, “ctenuchid” will still be the first name that comes to my mind.

REFERENCE:

Lafontaine, J. D. and B. C. Schmidt.  2010.  Annotated check list of the Noctuoidea (Insecta, Lepidoptera) of North America north of Mexico.  ZooKeys 40:1–239.  doi: 10.3897/zookeys.40.414

Copyright © Ted C. MacRae 2011



A First Class Box of Beetles

Warning: post contains lots of hardcore, beetle-collector geekery!

A nice selection of tiger beetles and buprestid beetles.

A few weeks ago I got an email from fellow buprestophile Henry Hespenheide (Professor Emeritus, UCLA) asking if I needed any specimens of Agrilus coxalis auroguttatus - recently dubbed the “goldspotted oak borer” after it was discovered damaging oaks in southern California (Coleman & Seybold 2008).  I replied that I did not have this species in my collection and that I would be grateful for any examples he could provide.  Shortly afterwards, I received another message from him saying that he had just placed in the mail a small box with a male/female pair of that species – along with about two dozen tiger beetles for my enjoyment!  Later that week I received the shipment at my office – I couldn’t wait to open it up and see what goodies were inside!

Ctenostoma maculicorne (Chevrolat, 1856)

Opening a box of just received specimens is a little like opening presents on Christmas – you don’t know for sure what’s inside, but you know you’re gonna like it!  This time was no exception, and I delighted as I realized the sending contained a dozen or so tiger beetles from Costa Rica and Nicaragua (a region in which Henry has spent many of his years studying the leaf-mining and twig boring buprestid beetles).  My eyes were immediately drawn to two tiger beetles in particular – specimen #1 in the first row, and specimen #4 in the second row.  Why these particular tiger beetles?  Obviously they are among the more showy specimens in the sending, but more significantly both of them belong to genera not represented in my collection.  The first of these is Ctenostoma maculicorne, representing also a new tribe for my collection (Collyridini, subtribe Ctenostomina).  I’m glad Ron Huber had already identified this specimen, as I probably would’ve only been able to determine the genus.  Beetles in this group are ant mimics, but in a much different manner than our U.S. ant-mimics (Cylindera cursitans and Cylindera celeripes).  Those latter species are found strictly on the ground (as are all U.S. tiger beetle species), while species of Ctenostoma are largely arboreal.  Troy Bartlett at Nature Closeups has some great photographs of another species in this genus seen last January in Brazil (Caraça Natural Park, Minas Gerais) that show just how ant-like these beetles can appear as they crawl about on twigs and branches.

Pseudoxycheila tarsalis Bates, 1869

Despite lacking an identification label, I recognized the second specimen instantly as Pseudoxycheila tarsalis, dubbed by Erwin & Pearson (2008) as the “Central American montane tiger beetle.”  Pseudoxycheila is a rather large Neotropical genus (21 known species), but only P. tarsalis occurs north of South America.  Morgan Jackson at Biodiversity in Focus photographed an individual of this species during his visit to Costa Rica this past summer.  Its brilliant coloration is not only delightful to look at but also apparently aposematic in nature – Schultz and Puchalski (2001) found that benzene-like compounds isolated from the beetle’s pygidial glands are distasteful to humans, adding support to the potential of a Müllerian mimicry association with stinging mutillid wasps in the genus Hoplomutilla, which they resemble.  Note also the curious spine on the frons extending out over the mandibles – maybe it not only grabs its prey with its toothy jaws but also “stabs” it for extra measure (just kidding – though I do wonder about the function of that spine.  I’m not aware of its presence in any other genus of tiger beetles).

I also noted an interesting pair of tiger beetles that looked very different from each other, yet were both identified by Ron Huber as Tetracha ignea.  This species was recently synonymized under the nominotypical form of T. sobrina (Naviaux 2007) – the “ascendent metallic tiger beetle” (Erwin & Pearson 2008), a highly variable species with numerous described subspecies occurring in southern Mexico, Central America, northern South America, and the West Indies.  The specimen on the left has the normal appearance of T. sobrina sobrina, but the specimen on the right looks like it might have suffered some chemical discoloration (a common occurrence among collected tiger beetle specimens).

Update 16 Dec 2010, 12:00pm – I just learned from Henry that the Tetracha specimen on the right (from Nicaragua) was not seen by Ron Huber and, thus, is likely not conspecific with the specimen on the left (T. sobrina from Costa Rica).  That’ll teach me to blindly accept what I see but does not seem right.  Now, time to pull out my copy of Naviaux (2007) and test my abilities to work through a key written in French!

Tetracha sobrina sobrina Dejean, 1831 (L); Tetrach sp. undet. from Guatemala (R).

There are several other interesting species in the sending – some determined (two species each of Oxycheila and Brasiella) and others that I need to look at more closely.  You may note on the bottom row a few specimens of a species of Elaphrus - a genus of true ground beetles that often fool collectors by their strong resemblance to tiger beetles (looks like they fooled Henry, too).  As for the beetles that were the reason for this shipment in the first place, these are shown in the image below.  Agrilus coxalis auroguttatus was recently discovered as the cause of significant mortality in several species of oak trees in San Diego County (Coleman & Seybold 2008), thus joining the introduced Agrilus planipennis (emerald ash borer) and several native Agrilus spp. on the ever-growing list of buprestid beetles achieving economic pest status in North America.  This subspecies, known for many years from southern Arizona (where it is not a pest), is curiously widely disjunct from nominotypical populations in southern Mexico.  Its sudden appearance in southern California has all the hallmarks of being a human-aided introduction, although natural range expansion remains a possibility.

Agrilus coxalis auroguttatus Schaeffer, 1905

My deep appreciation to Henry Hespenheide for gifting me these specimens and for his always enlightening and often entertaining correspondence over the years.

REFERENCES:

Coleman, T. W. and S. J. Seybold.  2008.  Previously unrecorded damage to oak, Quercus spp., in southern California by the goldspotted oak borer, Agrilus coxalis Waterhouse (Coleoptera: Buprestidae).  The Pan-Pacific Entomologist 84:288–300.

Erwin, T. L. and D. L. Pearson. 2008. A Treatise on the Western Hemisphere Caraboidea (Coleoptera). Their classification, distributions, and ways of life. Volume II (Carabidae-Nebriiformes 2-Cicindelitae). Pensoft Series Faunistica 84. Pensoft Publishers, Sofia, 400 pp.

Naviaux R. 2007. Tetracha (Coleoptera, Cicindelidae, Megacephalina): Revision du genre et descriptions de nouveaus taxons. Mémoires de la Société entomologique de France 7:1–197.

Schultz, T. D. and J. Puchalski.  2001.  Chemical defenses in the tiger beetle Pseudoxycheila tarsalis Bates (Carabidae: Cicindelinae).  The Coleopterists Bulletin 55(2):164–166.

Copyright © Ted C. MacRae 2010



Clown beetle surprise

As I slowly scanned my flashlight through the darkness across the mixed-grass prairie in the Glass Mountains of northwestern Oklahoma last July, there was one thing that I hoped not to see (prairie rattlesnake, unless from afar) and one thing that I hoped more than anything to see (Great Plains giant tiger beetle, Amblycheila cylindriformis). Fortunately, I encountered none of the former and found several of the latter.  It took awhile before I saw the first one, but in the meantime I saw all too abundantly the clown beetle, Eleodes suturalis.  A member of the family Tenebrionidae, this species is one of the most conspicuous components of the Great Plains beetle fauna.  Adults are commonly encountered walking about the grasslands or crossing roads, especially after summer rains.  I recall my first encounter with this species when I made my first insect collecting trip to the Great Plains in 1986, marveling as I literally watched hundreds of individuals crossing a remote highway in southwestern Kansas.  Now, they were just an annoyance – close enough in size and appearance to the object of my search that I had to pause and look at each one I encountered to verify its identity.¹

¹ In fact, a mimetic association has been suggested for Amblycheila cylindriformis and Eleodes suturalis due to their similarity in size, shape and coloration (black with a reddish-brown sutural stripe) (Wrigley 2008).  This may be true, as Eleodes suturalis is an abundant species capable of defending itself with noxious sprays that contain benzoquinone and other hydrocarbons, while Amblycheila cylindriformis is a much rarer species (as mimics tend to be) that lacks defensive compounds.

After finding a few of the Amblycheila, I encountered this particular individual clinging to a root sticking out of the side of a wash.  My closer look caused it to immediately assume its characteristic defensive headstand pose (from which the name ‘clown beetle’ comes), so I decided to take a few photographs (not an easy task at night).  The photos have been sitting on my hard drive since, but in examining them more closely, I realized that this particular beetle is not E. suturalis.  Rather, it is one of several similar appearing species that co-occur with E. suturalis in the Great Plains and sometimes resemble it due to their large size, sulcate elytra, and occasional presence of a similar reddish-brown sutural stripe.  From these species, E. suturalis is at once distinguished by its broadly explanate (flanged) pronotum and laterally carinate, distinctly flattened elytra.  This individual clearly exhibits more rounded elytra and as best as I can tell keys to E. hispilabris – distinguished from E. acuta and E. obscurus by possessing a normal first tarsal segment (not thickened apically) on the foreleg (Bennett 2008).  Presumably this and the other related species of Eleodes also possess chemical defenses similar to E. suturalis – an example of Müllerian mimicry where multiple species exhibit similar warning coloration or behavior (in this case headstanding) along with genuine anti-predation attributes.

Photo Details: Canon 50D (ISO 100, 1/250 sec, f/14), Canon 100mm macro lens, Canon MT-24EX flash (1/4 ratio) w/ Sto-Fen diffusers. Post-processing: levels, unsharp mask, slight cropping.

REFERENCES:

Bernett, A. 2008. The genus Eleodes Eschscholtz (Coleoptera: Tenebrionidae) of eastern Colorado. Journal of the Kansas Entomological Society 81(4):377–391.

Wrigley, R. A.  2008. Insect collecting in Mid-western USA, July 2007.  The Entomological Society of Manitoba Newsletter 35(2):5–9.

Copyright © Ted C. MacRae 2010

The Moth and Me #11

Welcome 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

Luna 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

Jason 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

Royal 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.

Aside 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.”

For 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!).

In 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.

Australia 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!).

Adults 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

Often 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

Many 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

Carolyn 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)?

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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 – Simple Maiden (Amata simplex)

Simple Maiden (Amata simplex) - 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).  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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