Mormotomyiids' Terrible Hairiness

There are many rare insects in this world of ours—species that have been collected only once, and have never been seen since. Due to their diminutive size or retiring habits or a simple dearth of investigation by Homo sapiens, we have no idea of their habits or distribution; and so we cannot know their true range or abundance. Thus, I would reason that many "restricted" insects are no doubt only rare in the eye of a human beholder.


(Rest assured that this essay will not take the form of an argument to the effect that, given our lack of understanding of the vast majority of insects, there is no need to protect them from anthropogenic destruction; and that any attempt to do so is most likely a wrongheaded effort by leftists to squelch free enterprise. Free enterprise, of course, being the only thing that makes life worth living, as I would sincerely claim if the American Enterprise Institute were paying me gobs of money.)

A. muwu, photographed by Alice Abela

But now that I've finished my digression towards the soapbox, I will reiterate that many insects appear unusual merely due to humans' blinkering by our large size. There are exceptions, however: if we understand an insect's habitat preferences and know that the said habitat is insular, we can safely extrapolate that insect's rarity. An exemplar of these would be Ammopelmatus kelsoensis (Stenopelmatidae), an arenophilous Jerusalem cricket known only from the isolated Kelso Dunes erg in the Mojave Desert ("Ammopelmatus kelsoensis"—Natural Diversity Database). (A similarly restricted congener is shown above.)

Another instance of a truly rare insect would be the primary subject of this post, the terrible hairy fly (Mormotomyia hirsuta), which is such a bizarre creature that it's placed in its own family (naturally dubbed Mormotomyiidae). Known only from a single crevasse cleaving a gigantic hilltop boulder (and a smaller, oblique nick in selfsame boulder) in northern Kenya (near Ukasi), this surreal creature has been seen only thrice since its discovery in 1933, and definitely not due to a lack of trying: seven attempts at collecting the terrible hairy fly have been mounted in the past 79 years, with only two of them having success.

A live Mormotomyia hirsuta

The dim, cave-like fissure is a roost for bats: and, where there are bats, there is guano. It is upon (and within) this that M. hirsuta's maggots feed (van Emden, 1950). This is hardly uncommon; guano is a very nutritious substance popular with all kinds of organisms, especially true fly larvae (Diptera): this is aptly demonstrated by the presence of no fewer than 6 families (not counting Mormotomyiidae) in the rich medium at Ukasi Hill (Kirk-Spriggs et al., 2011). What is unusual is mormotomyiids' adult appearance: very hirsute (hence the name), with proportionally longer leg setae in males; no ocelli; gangly, and uncannily recalling a windscorpion (order Solifugae); and (most importantly) flightless, with the wings reduced to bristly projections (Austen, 1936). The long hair of males probably serves a function in sexual selection, making them appear larger (and therefore hardier) to potential mates (Copeland et al., 2011). The terrible hairy fly's morphology shows heavy specialization for a troglobitic (cave-dwelling) lifestyle; that much is clear. However, the adults' precise relationship with the bats upon which they indirectly depend remains uncertain (Kirk-Spriggs et al, 2011). 

A Swiss bat fly (Nycteribiidae) on its host, photographed by Giles San Martin

Three families with a similar appearance—Streblidae, Nycteribiidae, and Mystacinobiidae—are notable here as points of comparison. The former two (sometimes classified as a single family; Petersen et al., 2007) are known as "bat flies", and are louse-like bloodsuckers of bats (duh): nycteribiids are rather more advanced in this respect, being blind, wingless, tiny-headed, and never parting with their hosts (Peterson & Wenzel, 1987); conversely, some streblid bat flies retain their wings and/or sight (Whitaker, 1988). Bat flies are also ovoviviparous (meaning that the female's eggs hatch in utero): yet another adaptation to obligate parasitism (Bequart, 1940). Mormotomyia's mouthparts, though, are unequivocally not designed for puncturing skin—they merely sponge up liquids (van Emden, 1950). Hence, the theory that the terrible hairy fly is a bat ectoparasite can be ruled out.

Mystacinobiids on their host (or, rather, symbiont); photograph by Rod Morris

Perhaps, then, the subject of this post is more comparable to the members of the Mystacinobiidae, another monotypic family of weirdo flies which also happen to be the only eusocial dipterans (Piper, 2007). They are found only in New Zealand, which, aside from wetas and Peter Jackson (you gotta love that country), is inhabited by an endemic species of short-tailed bat that plays host to these flies. Mystacinobia zealandica, however, is not a sanguivore (blood-eater); instead, it subsists on the bats' secretions and excreta (Holloway, 1976). The New Zealand bat fly even spends a good deal of its time off-host: and thus its relationship with the creatures whose "fundiment" (to quote Geoffrey Chaucer) it eats isn't parasitic, but phoretic. Might the terrible hairy fly also be a bat cleaner? Extrapolating from its delicate long-legged habitus, which contrasts with the leathery muscularity of the flies seen above, probably not: the creature is free-living; a dasher-over-rocks, rather than a climber-through-fur (Kirk-Spriggs et al., 2011).

Due to its peculiarity, the classification of Mormotomyiidae has been contentious, being included within two unrelated superfamilies: the Sphaeroceroidea (Austen, 1936; Griffiths, 1972; McAlpine, 1989) or Muscoidea (van Emden, 1950 and Pont, 1980). The two are unrelated, the latter belonging to the Calyptratae (a clade including blowflies, flesh flies, houseflies, etc.) and the former, Acalyptratae: a paraphyletic grab-bag consisting of all ptilinum*-bearing flies tha (aren<'t calyptrates. Study of the female genitalia (those dipterist perverts), by contrast, strongly indicates placement in the Ephydroidea (Acalyptratae; Kirk-Spriggs et al., 2011), along with the very familiar laboratory fruit fly (Drosophilidae): the only ephydroids that so much as superficially resemble the terrible hairy fly would be the bee lice (Braulidae), stocky, mite-like little (1.6 mm.) commensals of honeybees (see drawing below), formerly placed in the Carnoidea (Wiegmann, et al., 2011). Larvae grow up in the honeycomb (Ellis & Nalen, 2010); adults are freeloaders who cling to bees and steal food from their hosts' mouths.

Braula coeca, from John Henry Comstock's A Manual for the Study of Insects (1895)

But now we must return to the terrible hairy fly itself. Its sporadic presence despite repeated searching is probably owed to the fact that rain is required to keep guano amicable to M. hirsuta maggots: and it so happens that the climate of northeastern Kenya is arid (c. 381 mm. of precipitation annually around Ukasi; Wright, 1964), with rain brief and very seasonal (Copeland et al., 2011). Thus, adults only make a brief annual (or semi-annual) appearance, their life-cycle being swiftly carried out while the weather permits, and remaining for the most part within the moist microclimate sustained inside their shaded clefts. It's probable that their eggs are capable of long periods of estivation in the times between life-giving torrents. 

So it is amply demonstrable that the terrible hairy fly is a creature intensively adapted for life in a very specific habitat; and that it cannot survive outside of said habitat. Moreover, the fact that the fly is a delicate creature, ill-shaped for phoresy, means that it is incapable of dispersal to new locales. Dormant eggs being carried off in guano stuck to birds' feet (by analogy to the similar phenomenon among seeds) is probably the only means by which terrible hairy flies could escape their cleft; but even if this happened, the likelihood of those eggs arriving in a hospitable environ remains a long shot. Therefore, it is most likely that the population on Ukasi Hill is the only one on Earth, a deduction confirmed by genetic evidence which also indicates a recent population bottleneck (Copeland et al., 2011). 

Even though M. hirsuta's numbers are good at the moment, the species remains very vulnerable. And whether or not you feel that the terrible hairy fly deserves our protection, I heartily hope that the sight that g reeted their discoverer, H. B. Sharpe—that of the flies drifting gently down from the walls " ... like feathers", borne by their long hair—will remain to be witnessed by humanity (or those members of it who happen to care) for many years to come. 




*The ptilinum is an inflatable sac located in a number of flies' heads (rather like an airbag): it is used to force open the end of the puparium to permit the new adult's eclosion. Afterwards, the ptilinum deflates, withdrawing into the head; a suture above the antennae's bases marks the place where it originated. The flies that bear this suture comprise a monophyletic group called the Schizophora (a subdivision of the infraorder Muscomorpha). 
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Ammopelmatus kelsoensis. (n.d.). Sandra Shanks. Retrieved 12/18/12 from http://www.dfg.ca.gov/biogeodata/cnddb/pdfs/invert/Insects_-_Orthoptera/Ammopelmatus_kelsoensis.pdf

Austen, E. E. (1936). A remarkable semi-apterous fly (Diptera) found in a cave in East Africa, and representing a new family, genus, and species. Proceedings of the Zoological Society of London, 425-431.

Bequart, J. (1940). Moscas parasiticas pupiparas de Colombia y Panama. Acad. Colombiana Cienc. Exac. Fis. Nat., 3, 414-418.

Copeland, R. S.; Kirk-Spriggs, A. H.; Muteti, S.; Booth, W.; and Wiegmann, B. M. (2011). Rediscovery of the "terrible hairy fly", Mormotomyia hirsuta Austen (Diptera: Mormotomyiidae), in eastern Kenya, with notes on biology, natural history, and genetic variation of the Ukasi Hill population [electronic version]. African Invertebrates, 52(2), 363-390. Retrieved 12/18/12 from http://www.africaninvertebrates.org.za/Uploads/8ba3321a-9a13-45e5-aaea-f4de4d15f02e/Copeland_etal_2011_AfrInvertebr_52_2_RediscoveryMormotomyia_LR.pdf

Ellis, J. D. and Nalen, C. M. Z. Bee Louse—Braula coeca Nitzsch. 2010. Retrieved 12/18/12 from http://entomology.ifas.ufl.edu/creatures/misc/bees/bee_louse.htm 


Griffiths, G. C. D. (1972). The Phylogenetic Classification of Diptera Cyclorrhapha, with Particular Reference to the Structure of the Male Postabdomen. The Hague: W. Junk.

Holloway, B. A. (1976). A new bat-fly family from New Zealand (Diptera: Mystacinobiidae). New Zealand Journal of Zoology, 3, 279-301.

Kirk-Spriggs A. H.; Kotrba, M.; and Copeland, R. S. (2011). Further details of the morphology of the enigmatic African fly Mormotomyia hirsuta Austen (Diptera: Mormotomyiidae) [electronic version]. African Invertebrates, 52(1), 145-165. Retrieved 12/17/12 from http://www.africaninvertebrates.org.za/Uploads/bdee00bd-7b45-4a66-aa77-afa03eda1936/kirkspriggs_etal_2011_AfrInvertebr_52_1_Mormotomyia_LR.pdf

McAlpine, J. F. (1989). Phylogeny and classification of the Muscomorpha. In Borkent, A.; McAlpine, J. F.; Wood, D. M.; and Woodley, N. E. (eds.), Manual of Nearctic Diptera, vol. 2. Ottawa: Agriculture Canada , Biosystematics Research Center, monograph 28, pp. 1069-1072.

Piper, R. (2007). Extraordinary Animals: an Encyclopedia of Curious and Unusual Animals. Westport: Greenwood Publishing Group. 

Pont, A. C. (1980). Superfamily Muscoidea. 81. Mormotomyiidae. In Crosskey, R. W. (ed.), Catalogue of the Diptera of the Afrotropical Region. London: British Museum (Natural History), p. 713.

Petersen, F. T.; Meier, R.; Kutty, S. N.; and Wiegmann, B. M. (2007). The phylogeny and evolution of host choice in the Hippoboscoidea (Diptera) as reconstructed using four molecular markers. Molecular Phylogenetics and Evolution, 45(1), 111-112. 

Peterson, B. V. and Wenzel, R. L. (1987). Nycteribiidae. In McAlpine, J. F.; Peterson, B. V.; Shewell, G. E.; Teskey, H. J.; Vockeroth, J. R.; and Wood, D. M. (eds.), Manual of Nearctic Diptera, vol. 2, Minister of Supply & Services, Ottawa, monograph 28, pp. 1283-1301. 

Van Emden, F. I. (1950). Mormotomyia hirsuta Austen (Diptera) and its systematic position. Proceedings of the Royal Entomological Society of London (B), 19, 121-128.

Whitaker, J. O. (1988). Collecting and preserving ectoparasites for ecological study. In Kunz, J. H. (ed.), Ecological and Behavioral Methods for the Study of Bats. Washengton: Smithsonian Institution Press, pp. 459-675.

Wiegmann, B. M.; Trautwein, M. D.; Winkler, I. S.; Barr, N. B.; Kim, J.; Lambkin, C.; Bertone, M. A.; Cassel, B. K.; Bayless, K. M.; Heimberg, A. M.; Wheeler, B. M.; Peterson, K. J.; Pape, T.; Sinclair, B. J.; Skevington, J. S.; Blagoderov, V.; Caravas, J; Kutty, S. N.; Schmidt-Ott, U.; Kampmeier, G. E.; Thompson, F. C.; Grimaldi, D. A.; Beckenbach, A. T.; Courtney, G. W.; Friedrich, M.; Meier, R.; and Yeates, D. K. (2011). Episodic radiations in the fly tree of life. Proceedings of the National Academy of Sciences, United States, 108. 

Wright, J. B. (1964). Geology of the Ndeyini Area. (Report #69.) Ministry of Natural Resources, Geological Survey of Kenya. Nairobi: Government Printer.

Little Bags of Horror: Three Obscure Families of Surreal Aculeates

Ah, the love of parasites that runs through our species--the grim fascination with the cloud of bacteria, protists, fungi, and animals that depend upon Homo sapiens for sustenance and shelter. The disgusted fixation on the worms that haunt our gut and veins, emitting eggs to be sent forth to other hosts via our, ah, "dark materials"...or maybe this is all just my personal fascination: mine, and that of the other members of this perverted cult.

Perhaps this fascination originates in our ontogeny: we, like all viviparous creatures, play host for our gestating, "parasitic" fetuses; and they suck away our vitality and alter our behavior (i.e., cause us to host baby showers and purchase adorably tiny shoes) for nine long months. ("Us" being mothers, of course. And, no, I am not a mother, or even a female. But anyway...) This grotesque mystique is what engenders such works as (for example) the "Alien" franchise, and ensures their continued popularity. 

Of course, any biologist worth his snuff knows that the eponymous extraterrestrial of the said horror franchise (fig. 1; drawn by H. R. Giger) is unequivocally not a parasite. It kills its host (in grisly fashion)--not by occasional accident, but by necessity. Therefore, it is a parasitoid: and parasitoids are infinitely more disturbing than true parasites.And insects (my particular area of expertise) harbor a wide range of parasitoids. Indeed, the 60,000 species of ichneumon wasps (Ichneumonidae), and the remainder of the panoply of parasitoid wasps, are perhaps the best-known exemplars of the lifestyle: a lifestyle whose prevalence was cited explicitly by Charles Darwin as evidence against a benevolent Creator (Gould, 1994). But I wouldn't post about something well-known, now would I? No; instead I will discuss some parasitoid wasp families that I think are sadly obscure.These families are included within the Aculeata--the clade of the order Hymenoptera consisting of those wasps (to use that term in a phylogenetic sense) that possess a stinger (a diagram of one can be found at right). As the organ is a specialized ovipositor, only females bear one (although a good deal of lineages have secondarily lost theirs). A stinger is a versatile instrument: one can use it for self-defense, to kill prey, subdue a rival, or even as an impromptu shish-kebab for carrying said prey back to one's nest (as Oxybelus sp. do; Peckham, 1985). Consequently, aculeates run a gamut of lifestyles: some are parasitoids that use their stingers to stun their offsprings' hosts; others use theirs to paralyze prey that will be hauled back to a burrow, where the individual will be devoured by the wasp's larvae; and still others use it in the service of their colony.Three superfamilies comprise the Aculeata: Chrysidoidea, Vespoidea, and Apoidea; all include some parasitoids. Interestingly, all aculeates who grow in that manner are ectoparasitoids: that is, they live and grow as larvae on their hosts' bodily exteriors (in contrast to most hymenopteran parasitoids, who dine from the interior). All of them, that is, except the members of two related families: the Dryinidae and Embolemidae.

Dryinids are odd to look upon, as one can see from the photograph by Stephen Luk at right of Dryinus alatus; their physique is fairly typical of a hymenopteran, but their demeanor has been compared to that of a long-legged fly (Micropezidae), and the most distinctive attribute of the Dryinidae (found only in the females) seems to have been robbed from some crustacean. I refer here to the wasps' chelae, or pincers. Females of most species (1,100 worldwide; van Noort, 2012a) possess them, with the exceptions belonging to the subfamilies Aphelopinae and Diaphelopinae (O'Neill, 2001). The pincers derive from a modification of the apical segment of the foreleg's tarsus--lengthened and tilted into a blade--and one of the tarsal claws, elongated and enlarged as a counterpoint to the aforementioned tarsal segment. The other tarsal claw (all insects have two) is either vestigial or absent (Olmi, 1984). (See the chela of an Anteon urbani at left.) The inner surfaces of the chela's two pinching scimitars may bear blunt lamellae, hairs, or some combination thereof to increase grip; female dryinids utilize their pincers to restrain the unfortunates who will be hosts for their larvae: leafhoppers (Cicadellidae) or planthoppers (usually Flatidae or Delphacidae).Since 12 families of bugs (all in the hemipteran suborder Auchenorrhyncha) are represented in the range of dryinid hosts (van Noort, 2012), the precise chelate design of the Dryinidae varies: ranging from the unadorned, robust ones of the Bocchinae to the diminutive pincers of the Gonatopodinae to the surreal sawtoothed futuristic-instruments-of-dental-torture (or something like those) borne by Megadryinus magnificus (Dryininae)--sadly, I was unable to locate a digital picture of these strangely narrow, rather fragile-appearing chelae (with 150 parallel rows of lamellae opposite a hundred pointed hairs), which account for 40% of the wasp's total length (O'Neill, 2001).But the most noteworthy peculiarity of the Dryinidae lies in their larvae, which, as I mentioned before, reside within--rather than without--their host, in contrast to the remainder of the Aculeata, which are ectoparasitoids almost as a rule. This difference in dryinid ontogeny makes an appearance even before hatching, since the mother lays the lone egg inside a host (inserting her ovipositor through a gap in the integument). After a brief period, though (Clausen, 1940), a dryinid larva's lifestyle shifts from that of a pure internal parasitoid to one lying somewhere between that state and that of an external one: its head remains embedded in the host, but the body hangs outside, protected from the elements by a thylacium--a bubble-shaped sack comprised of accumulated larval exoskeletons. Despite the fact that this encumbrance is hardly concealed (see photograph by Claude Pilon at right), the host goes on its merry way as if nothing were amiss; at least, that is, until the time comes for the larva's pupation: then the dryinid ruptures its thylacium and devours the host in plain sight. What a rude awakening awaits the planthopper nymph (Fulgoridae) above. With the exception of the aphelopine Crovettia theliae (an endoparasitoid for the duration of the larval stage, and incidentally the only aculeate to exhibit polyembryony*; Kornhauser, 1919), all Dryinidae create a thylacium. So does the single member of the closely related (Carpenter, 1986) Embolemidae whose habits are known. In contrast to the diverse Dryinidae, only twenty species of embolemid are described (van Noort, 2012b), and they are seldom collected. Sexual dimorphism is strong, with the fleet-footed females conspicuously lacking in wings (Watson & Dallwitz, 2003): see the specimen of Embolemus nearcticus collected by Jeff Gruber above. (A good number of female dryinids are apterous as well.) These females are soil-dwelling; they have been noted as residing in ant nests (Donisthorpe, 1927) and mammal burrows (Heim de Balsac, 1935), but why they do so is anyone's guess, since the only known embolemid hosts (belonging to Ampulicomorpha confusa) are planthopper nymphs (Achilidae; Birdwell, 1958), which are not noted for a fossorial lifestyle.These two singular families, Dryinidae and Embolemidae, are members of the Chrysidoidea, a good-sized superfamily mostly comprised of small, obscure taxa (7 in all): of these only the brilliantly metallic cuckoo wasps (Chrysidinae), named for their brood parasitism of assorted solitary bees and wasps, are familiar to the general public. This is not the case with another previously-mentioned aculeate superfamily--the Vespoidea, which includes all social wasps (in three subfamilies of Vespidae), potter wasps (Vespidae: Eumeninae), the notorious tarantula hawk wasps (Pepsis sp., Pompilidae), the velvet ants (Mutillidae), and the ubiquitous ants (Formicidae), to name but the famous ones. Of course, a good share of vespoid families (10 living) are just as little-known as the average chrysidoid taxon. Among these is the last family of parasitoid wasp to be discussed in this post: the Rhopalosomatidae.Rhopalosomatids (38 spp.) are rare ectoparasitoid wasps that in most genera (as adults) strongly resemble ichneumonids: the eastern North American Rhopalosoma nearcticum (above, photographed by Rich Hoyer) bears a strikingly ophionine mien. Those in the genus Olixon, however, are brachypterous, with rudimentary flaps for wings (see the holotype of O. toliaraensis at left) and could be easily mistaken for velvet ants: in fact, the genus was initially classified in the Ichneumonidae (presumably on the basis of a seeming resemblance to certain members of the Phygadeuontini, a tribe in that family), and placed variously in the Pompilidae, Bethylidae, Braconidae, and none other than the Dryinidae throughout the late nineteenth and early twentieth centuries (Guidotti, 1999). Olixon is also unique among flightless hymenopterans in that (insofar as I can tell) both genders are brachypterous.Rhopalosomatids warrant description in this post because of their larvae, which are protected by sacs of accumulated exuviae strongly reminiscent of the aforementioned chrysidoid, half-endoparasitoid families' thylacia (Gurney, 1953). Despite this resemblance, the young of Rhopalosomatidae are just as much ectoparasitoids as other Vespoidea. Why, then, the quasi-thylacium? Probably the shelter is necessary because rhopalosomatid hosts are exclusively crickets (Gryllidae), which remain very much active even during their affliction (see photograph by Roy Sigafus at right): by contrast, most vespoid parasitoids feed on insects with more recumbent habits, or ones that at least dwell in unexposed environs (e.g., the ever-popular subterranean scarab beetle grubs). This feature--"little bags of horror"--is what makes the Rhopalosomatidae so peculiar (and the other two families discussed herein as well).Well, then: now that I have poured further carbon dioxide into our already overloaded atmosphere via the usage of this computer, I will bid farewell to any readers who may peruse this inaugural post of Life, et al.   *To put it succinctly, polyembryony is a state with which OctoMom is all too familiar. _______________________________________________________________ Birdwell, J. C. (1958). Biological notes on Ampulicomorpha confusa Ashmead and its fulgoroid host. Proceedings of the Entomological Society of Washington, 60, 23-26. Carpenter, J. M. (1986). Cladistics of the Chrysidoidea. Journal of the New York Entomological Society, 94, 303-330. Clausen, C. P. (1940). Entomophagous Insects. New York City: McGraw-Hill. Donisthorpe, H. St. J. K. (1927). The Guests of British ants: their Habits and Life-Histories. London: G. Routledge & Sons. Heim de Balsac, H. (1935). Ecologie de Pedinomma rufescens Westwood; sa presence dans les nids des micromammiferes (Hym. Embolemidae). Revue Francaise d'Entomologique, 2, 109-112. Gould, S. J. (1994). Hen's Teeth and Horse's Toes: Further Reflections in Natural History. New York City: W. W. Norton. Guidotti, A. E. (1999). Systematics of Little-Known Parasitic Wasps of the Family Rhopalosomatidae (Hymenoptera: Vespoidea) [electronic version]. University of Toronto (unpublished). Retrieved 12/9/12 from https://tspace.library.utoronto.ca/bitstream/1807/14562/1/MQ46189.pdf Gurney, A. B. (1953). Notes on the biology and immature stages of a cricket parasite of the genus Rhopalosoma. Proceedings of the United States National Museum, 103, 19-34.Kornhauser, S. I. (1919). The sexual characteristics of the membracid, Thelia bimaculata (Fabr.) J. Morphol., 32, 531-636.   Olmi, M. (1984). Revision of the Dryinidae. Memoirs of the American Entomological Institute, 37, 1-1913.O'Neill, K. M. (2001). Solitary Wasps: Behavior and Natural History. Ithaca: Cornell University Press.   Peckham, D. J. (1985). Ethological observations on Oxybelus (Hymenoptera: Sphecidae) in southwestern New Mexico. Annals of the Entomological Society of America, 78, 865-872.Van Noort, S. (2012a). Dryinidae: dryinid wasps of Africa and Madagascar. Retrieved 12/9/12 from http://www.waspweb.org/Chrysidoidea/Dryinidae/index.htm Van Noort, S. (2012b). Embolemidae: embolemid wasps of Africa and Madagascar. Retrieved 12/9/12 from http://www.waspweb.org/Chrysidoidea/Embolemidae/index.htmWatson, L. & Dallwitz, M. J. (2003). British Insects: the Families of Hymenoptera. Retrieved 12/7/12 from http://delta-intkey.com/britin/hym/www/embolemi.htm