crypsis

Bizarre, beautiful extremes

/ Ted C. MacRae / 8 Comments

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

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

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

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

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

Oaxaca)

Campylocentrus sp. (Mexico: Oaxaca)

Oaxaca)

Hyphinoe obliqua (Mexico: Oaxaca)

Puebla)

Poppea setosa (Mexico: Puebla)

Oaxaca)

Umbonia reclinata (Mexico: Oaxaca)

Puebla)

Umbonia crassicornis male (Mexico: Puebla)

umbonia_crassicornis_female

Umbonia crassicornis female (Mexico: Puebla)

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

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

treehopper_drawer
REFERENCES:

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

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

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

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

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

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

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

*Subfamily HETERONOTINAE

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

Subfamily MEMBRACINAE

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

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

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

Subfamily DARNINAE

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

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

Subfamily SMILIINAE

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

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

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

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

Subfamily STEGASPINAE

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

Family AETALIONIDAE
Subfamily AETALIONINAE

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

Copyright © Ted C. MacRae 2009

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Lions in South Africa

/ Ted C. MacRae / 9 Comments

Joerie, Joerie, botter en brood,
as ek jou kry, slaat ek jou dood.

Doodlebugs, joerie, shunties, toritos—these are but a few of the many colloquial names given to amusing little creatures that many people know simply as antlions (or translation of such) (Swanson 1996).   Larvae of winged insects resembling (but unrelated to) dragonflies, they are best known for their habit of digging smooth-sided, cone-shaped pits in sandy soils and concealing themselves under the sand at the bottom.  There, they lay in wait for some small, unsuspecting creature—often an ant—to fall into the pit.  When that happens, the hidden antlion bursts forth, using its oversized, sickle-shaped mandibles to “flick” sand at the prey to keep it sliding towards the bottom of the hole.  Once it is within reach, the antlion grabs the prey using those same, deadly mandibles (how delightfully morbid!).  So otherworldly is their appearance and behavior that, in addition to inspiring children’s charms, they have served as an unmistakable model for the “Ceti eels” featured in Star Trek: The Wrath of Khan!1  Adults of this group, on the other hand, have inspired far less imagination in nomenclature and culture, to the point that even their common name “antlion lacewing” is merely a reference back to their unusual larvae.  Even the scientific name of the family—Myrmeleontidae—has failed to garner complete adherence, with “Myrmeleonidae” (who needs the “t”?) and “Myrmelionidae” (perhaps from English-speakers focused on the English spelling of “lion” rather than the Latin spelling of “leo”) still appearing in popular and even scientific literature.

1 Sadly (and ironically), actor Ricardo Montalban, who played the villain Khan Noonien Singh in that movie (reprising a character he played 15 years earlier during the debut season of the Star Trek television series), died just eight days ago at the age of 88. I must confess that I am a life-long Star Trek fan (though not a “Trekkie”), and “Wrath” was certainly among my favorite of the movies, due in large part to Montalban’s steely, venomous portrayal of Kahn. My favorite line occurs as Kahn is about to put a Ceti eel in Chekov’s ear, explaining how they wrap themselves around the victim’s cerebral cortex. He then says, “Later, as they [pauses deliciously] grow…”

myrmeleontidae-larval-pitI’ve seen antlion pits on several occasions (especially in recent years as I’ve spent more time in open sand habitats searching for my beloved tiger beetles).  However, the pit pictured here—encountered at Borakalalo National Park in South Africa’s North West Province, was the first I’d ever seen in which there was actually an ant inside the pit.  The ant was dead, presumably having already been sucked dry by the joerie. I didn’t know it at the time, but southern Africa is a major evolutionary center for antlion lacewings and some of their striking relatives such as spoonwinged and threadwinged lacewings (family Nemopteridae) and silky lacewings (family Psychopsidae) (Grimaldi & Engel 2005).  Relatively few of South Africa’s antlions, however, actually dig pits—a habit restricted to species in the genera Hagenomyia, Cueta, and the cosmopolitan Myrmeleon (Scholtz & Holm 1985).  Rather, the majority of species have free-living larvae that hide under objects or roam under deep sand from where they emerge to hunt other insects.

Palpares lentusThis adult antlion lacewing came to an ultraviolet light at our encampment on the Geelhoutbos farm near the Waterberg Range (Limpopo Province). Its tremendous size and distinctly patterned wings placed it in the tribe Palparini, of which the genus Palpares is the most diverse. These are the true giants of the family, with forewing lengths that can reach 75 mm (that’s 3 inches, folks!) and both wings bearing conspicuous patterns of black and yellow markings (the yellow doesn’t show well in this photograph due to illumination by the ultraviolet light).  The larvae, understandably, are also quite large, and have even been observed to capture ground resting grasshoppers (Capinera 2008).  I sent this photograph to Dr. Mervyn Mansell, an expert on African Myrmeleontidae, who kindly identified the individual as a female Palpares lentus, endemic to northern South Africa and Zimbabwe. When queried for more information regarding its biology, Dr. Mansell responded:

We know nothing about P. lentus, except for distribution records. Nothing is known about its larva or biology, although the larvae of all Palpares and related genera are obviously large, and live freely in sand well concealed and almost impossible to find.

Palpares lentus is one of 42 species of Palparini in southern Africa—half of all known species in the tribe.  Nearly two-thirds of them are endemic to “open” biomes in the dry western parts of the subregion (Mansell & Erasmus 2002).  This high level of endemism results from the occurrence of large tracts of sand and exposed soil that are conducive to the large sand-dwelling larvae.  Eastern parts of the subregion containing forest or thicket biomes are not as favored by antlion lacewings, and consequently the diversity of species in these areas is much lower.  Because of their great size, palparine adults are especially vulnerable to predation, with the result that they have evolved elaborately patterned wings to enhance their camouflage—apparently an adaptation to the dappled shade provided by the fine-leafed plants found in these biomes.  While many species in the tribe are diurnal, a few in the related genus Palparellus pulchellus and P. ulrike are known to be attracted to light, spending the day resting concealed amongst vegetation. The attraction of this individual to our ultraviolet light suggests Palpares lentus has similar habits.

Everything you want to know about antlions can be found at Mark Swanson’s excellent website, The Antlion Pit. For information specific to Africa, Mervyn Mansell has assembled a checklist of The Antlions (Neuroptera: Myrmeleontidae) of South Africa, and a nice summary of antlions in Kruger National Park by Dave Rushworth can be found at Destination Kruger Park. I thank Dr. Mansell for his identification of Palpares lentus.

REFERENCES:

Capinera, J. L. (ed.).  2008. Encyclopedia of Entomology, 2nd Edition. Springer, Dordrecht, The Netherlands. 4346 pp.

Grimaldi, D. and M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press, New York, xv + 755 pp.

Mansell, M. W. and B. F. N. Erasmus. 2002. Southern African biomes and the evolution of Palparini (Insecta: Neuroptera: Myrmeleontidae). Acta Zoologica Academiae Scientiarum Hungaricae 48 (Suppl. 2):175–184.

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

Swanson, M.  1996. The Antlion Pit: A Doodlebug Anthology. http://www.antlionpit.com/

Two new species of Agrilus from Mexico

/ Ted C. MacRae / 4 Comments

ResearchBlogging.orgThe enormous, cosmopolitan genus Agrilus (family Buprestidae – commonly called jewel beetles or metallic woodboring beetles) contains nearly 4,000 described species (Bellamy 2008). With many more still awaiting description, it is perhaps the largest genus in the entire animal kingdom (Bellamy 2003). Agrilus species are primarily twig and branch borers, utilizing recently dead wood for larval development – although there are notable exceptions, e.g. Agrilus anxius (bronze birch borer), A. bilineatus (twolined chestnut borer), and A. planipennis (emerald ash borer), which attack the trunks of living trees and, thus, are of significant economic importance in forest and ornamental landscapes. Host specificity among Agrilus species ranges from highly monophagous – associated exclusively with a single plant species – to rather oliphagous – utilizing several, usually related, plant genera. Adults of Agrilus species are most often found on the foliage of their larval hosts and do not generally visit flowers, as is common in some other genera (e.g., Acmaeodera and Anthaxia). Interestingly, despite the diversity and worldwide distribution of the genus, no species of Agrilus are known to be associated with coniferous plants – a fact that has limited their expansion into the vast northern boreal forests.

Texas, Bexar Co., San Antonio, nr. Fort Sam Houston, em. 25.iv-14.v.1997 ex Phoradendron tomentosum coll. ii.1997, D. Heffern & D. W. SundbergAs can be imagined by its enormity, a comprehensive understanding of the genus will remain a distant goal for many years. Progress will come incrementally, as formal descriptions of new species gradually improve our knowledge of the fauna that exists in each of the world’s main biogeographic provinces. In a recent issue of the online journal Zootaxa, Dr. Henry Hespenheide (UCLA) describes two new species of Agrilus from Mexico. These two species are interesting because of their association with ‘mistletoe’ plants in the genus Phoradendron (family Viscaceae1), obligate hemiparasites that attach to branches and stems of various woody trees and shrubs in tropical and warm temperate regions of the New World. Plants in this genus are known to support a variety of host-restricted insect herbivores, principally in the orders Hemiptera, Coleoptera and Lepidoptera. A single buprestid species has been associated with Phoradendron to this point – Agrilus turnbowi, recently described from specimens reared from dead stems of Phoradendron tomentosum attached to mesquite (Prosopis glandulosa) in southern Texas (Nelson 1990) and pictured here from a specimen in my collection that was reared from dead mistletoe collected at the type locality. At the time of its description, this species was not relatable to any of the other known species in the genus.

1 The Angiosperm Phylogeny Group (2003) includes the Viscaceae in a broader circumscription of the family Santalaceae. However, recent molecular studies suggest the Santalaceae are polyphyletic, with strong support for Viscaceae as a distinct, monophyletic clade (Der & Nickrent 2008).

The two new Mexican species – A. andersoni from Guerrero and Puebla (Figs. 1-3), and A. howdenorum from Oaxaca (Figs. 4-6) – are apparently related to A. turnbowi, which they resemble by their purplish-red coloration and complex pattern of golden setae on the elytra. They are also superficially very similar to each other but differ most notably in size and the overall color and pattern of setae on the elytra.

Figures 1–3. Agrilus andersoni Hespenheide: 1. dorsal habitus; 2. lateral habitus (scale bar indicates 2.0 mm); 3. genitalia of male (scale bar indicates 0.5 mm) (from Hespenheide 2008).

Figures 4–6. Agrilus howdenorum Hespenheide: 4. dorsal habitus; 5. lateral habitus (scale bar indicates 2.0 mm); 6. genitalia of male (scale bar indicates 0.5 mm) (from Hespenheide 2008).

Hespenheide speculates that the color and pattern of the golden setae on the elytra may serve to make the beetles less conspicuous by disruptive coloration, noting the similar coloration of the setae to the leaves of Phoradendron as seen in the photograph of Agrilus howdenorum on its host plant (Fig. 7). This form of crypsis may also be enhanced by the purplish-red ground coloration of the adult, which resembles that of the small, darkened blemishes often observed on the foliage of these plants.

Figure 7. Agrilus howdenorum adult on mistletoe host plant near Diaz Ordaz, Oaxaca, México. The golden setae on the elytra are similar in color to the leaves of the mistletoe and may function as a disruptive color pattern. Photograph by C.L. Bellamy (from Hespenheide 2008).

REFERENCES

Angiosperm Phylogeny Group. 2003. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society, 141: 399-436.

Bellamy, C. L. 2003. The stunning world of jewel beetles. Wings, Essays on Invertebrate Conservation, 26(2): 13-17.

Bellamy, C. L. 2008. A World Catalogue and Bibliography of the Jewel Beetles (Coleoptera: Buprestoidea), Volume 4: Agrilinae: Agrilina through Trachyini. Pensoft Series Faunistica No. 79, 722 pp.

Der, J. P. & D. L. Nickrent. 2008. A Molecular Phylogeny of Santalaceae (Santalales). Systematic Botany, 33(1):107-116.

Hespenheide, H. A. (2008). New Agrilus Curtis species from mistletoe in México (Coleoptera: Buprestidae) Zootaxa, 1879, 52-56

Nelson, G. H. 1990. A new species of Agrilus reared from mistletoe in Texas (Coleoptera: Buprestidae). The Coleopterists Bulletin, 44(3):374-376.