Archive for the ‘Oribatida’ Category

Mites in the News

February 4, 2015

Zerconid_Idaho_3As the Good Book says: “To every thing there is a season, and a time to every purpose under the heaven” (Ecclesiastes 3:1). The last year hasn’t been the season for much new at Macromite’s Blog. Mites, alas, have been getting short shrift and I’ve been chasing platypus and butterflies and littering Facebook with the result. However, while I’ve been trudging around my new neighbourhood under the skeptical gazes of the kookaburras and wallabies, others have taken up the mite-art palette and brush with outstanding success.

Sam Bolton (or ‘Bolten’ as The Guardian misspelled his name) struck first in classic greyscale with his ‘Buckeye Dragon Mite’. Such is the power of a good monster picture that I’m told his paper was the most downloaded from The Journal of Natural History last year. Let’s hope someone also cites the paper in a scientific journal or two.

http://researchnews.osu.edu/archive/newmite.htm

http://smithsonianscience.org/2014/03/new-dragon-like-mite-found-in-ohio-is-gentle-reclusive/

And now, Martin Oeggerli’s long quest to bring the wonders of the acarine world to the public’s attention has been fulfilled. Quite a spectacular feat, both in colour use and in attracting the attention of National Geographic, something that several acarologists that I know of were not able to do. But if you compare Martin’s header image – a zerconid mite – with my more pedestrian zerconid image above, it is easy to understand his success. The text is by Rob Dunn (and The Inquisitive Anystid and I checked it for accuracy).

http://www.micronaut.ch/mighty-mites-micronaut-feature-article-published-by-national-geographic/

http://ngm.nationalgeographic.com/2015/02/mites/dunn-text

For those who are not squeamish (and if you are please don’t go there), y0u can see Rob among others bringing you up-to-date on follicle mite research in this video:

https://www.youtube.com/watch?v=KHDDCySUCIk

Even I am feeling itchy after watching that, but at least the rumour they explode on your face has been put to rest.

 

Carabodes = like a beetle or maybe a boat

September 12, 2013

Image

One wonders what was going on in the mind of Carl Ludwig Koch when he proposed the genus Carabodes in 1835. The Greek root karabos also gives us the familiar carabid beetles and apparently was used by the ancient Greeks to refer to a beetle of some sort – and also for a shell-like boat. The Greek suffix –odes refers to similarity or likeness, so I must assume that Professor Koch found his beetle mite more beetle-like than most. Then again, maybe he thought it looked more like a boat.

There is no mystery, though, why Marcel Reeves called the above species polyporetes. Although he found this species in moss, lichens, various litters, and rotting wood, it seemed especially common in bracket fungi including Tramtes versicolor (from which this specimen was collected). Reeves (1991) cultured this species on the polypores Oxyporus populinus, Lenzites betulina and Laetiporus sulphureus. At room temperature development took 10-12 weeks. Room temperature is a rather vague term, but presumably 20-25 C, a much higher temperature than would be expected in bracket fungi in a northern forest.

The mite below, Carabodes labyrinthicus (Michael, 1879), extends well up into the Arctic tundra of northern Canada and Alaska, as well as well up the trunks of trees in more southerly areas (Andre 1975). The labyrinthine name undoubtedly comes from the tortuous tuberculate ridges on its back. Schneider (2005) placed this mite in her phycophage/fungivore feeding guild  – it feeds on lichens and algae. When they aren’t burrowing in fungal sporocarps, lichens seem to be a preferred host for Carabodes species. In another laboratory study, Serge Ermilov introduced adult Carabodes subarcticus Trägårdh, 1902, to culture vials with lichens and algae. Adults fed primarily on Cladonia lichens and less so on Pleuroccocus algae. Larvae appeared 4-5 weeks later and burrowed into the lichen thallus. New adults appeared after 86-145 days, similar to the developmental period (69-202 days) of Carabodes willmanni Bernini, 1975, also reared on Cladonia lichens (Bellido 1990).

Carabodes_labyrinthicus_dorsal

References:

Andre, H. 1975. Observation sur les Acariens corticoles de Belgique.” Fondation Universitaire Luxembourgeoise. Serie Notes de Recherches 4: 5–31.

Bellido, A. 1990. Caracteristiques biodemographiques d’un acarien oribate (Carabodes willmanni) des pelouses xerophiles, Canadian Journal of Zoology 68: 2221–2229.

Ermilov, S.G. 2011. The biology of the development of the oribatid mite Carabodes subarcticus (Acari, Carabodidae). Entomological Review 91: 515–523

Reeves, R.M. 1991. Carabodes niger Banks, C. polyporetes n. sp., and unverified records of C. areolatus Berlese (Acari: Oribatida: Carabodidae) in North America, Canadian Journal of Zoology 69: 2925–2934.

Schneider, K. 2005. Feeding biology and diversity of oribatid mites (Oribatida, Acari). PhD thesis, Technical University, Darmstadt, Germany.

How many mites can dance on the head of a pin?

August 7, 2013

Dancing_pinhead_300_micron_grid_DEW

The answer, of course, depends on the pin and the mites. In this case the pinhead is about 2.5 mm in diameter and the mites a collection of oribatids from Alberta with plenty of room left over to dance. The question, I suppose, is a bit belaboured, but I’ve frugally wrung one paper and two talk titles from dancing on a pinhead. Admittedly the journal is a bit obscure (sorry Record of the WA Museum) and the talks on either side of the Pacific, so I doubt anyone noticed the duplication.  All or most of these mites have appeared here before and most were collected either at the Meanook Field Station or at our Moose Pasture. Speaking of which reminds me of another flight of fancy that I have used in at least four talks and one book – the Moose Pasture Miteome.

Miteome_Moose Pasture Moose

The mitochondria people already laid claim to  the succinct ‘mitome‘ for their mitochondrial genome database. Drat. Well, we’ve laid claim to ‘miteome’ for the unseen diversity of mites that form a substantial part of the weft and warp of the diversity tapestry. I’ve just sent off the corrected proofs of Mites: Ecology, Evolution & Behaviour (2nd Edition). Life at a microscale to Springer and the book should soon be available at an almost reasonable price. If you are interested in stories about mites – with lots (well over 100) of pictures – then you may find it of interest. As for me, though, I’m beat and have promised myself never to write another book on mites. I think I’ve said about all I can and now it is time for someone else to take up the load.

Tuparezetes: A hairy mite with a penchant for hairy leaves

June 16, 2013
Tuparezetes nymph - Scale bar = 0.1 mm

Tuparezetes nymph – Scale bar = 0.1 mm

Oribatid mites are a dominant component of the microfauna of forest soils throughout the world, but they also climb trees. The last post’s Neotrichozetes is one such arboreal beastie as is this week’s Tuparezetes. One clue to its arboreal life style is the globular head of the sensillus (what oribatid workers call the bothridial seta in a trichobothrium). Another is the long stiff-haired look.

Tuparezetes nymph dorsal view - Scale bar = 0.1. mm

Tuparezetes nymph dorsal view – Scale bar = 0.1. mm

These shots are of an immature Tuparezetes, probably a tritonymph. All stages can be found on shrubs and trees with densely hairy leaves in cool temperate to tropical rainforests in eastern Australia and in New Zealand where they graze on fungi growing among the hairs. The genus was described by AV Spain in 1969 and the type species, Tuparezetes christineae, was collected from Leatherwood or Tupare (hence the generic name): Olearia colensoi, a kind of shrubby daisy in the subalpine zone of New Zealand. He also described a second species, Tuparezetes philodendrus, from Nothofagus solandri and Olearia lacunosa.  In Australia, I collected the genus (probably undescribed species) from Blanketleaf (Bedfordia arborescens) in cool temperate rainforest in Victoria, from canopy fogging in subtropical rainforest in Lamington National Park and from an unidentified tropical rainforest tree near Paluma in Queensland.

Adult Tuparezetes showing wax cap (modified from Hunt et al. 1998).

Adult Tuparezetes showing wax cap (modified from Hunt et al. 1998).

I’ve always considered Alister Spain’s descriptions a model of how a taxonomic paper should be. As well as a detailed morphological analysis the genus and species are based on numerous collections and there is a section on the ecology of  each species including the identification of fungal species found in gut contents. In not sure that I agree with Alister’s explanation for the most bizarre feature of this mite, though – the deep waxy crest present between the dorsal setae. He suggests this is an arboreal adaptation related to water balance, but the hairy leaves that this mite inhabits should have a well developed boundary layer and good humidity retention even in high winds. Still, I have no better hypothesis to offer.

References

Hunt, G., Colloff, M.J., Dallwitz, M., Kelly. J. & Walter, D.E. 1998. An interactive key to the oribatid mites of Australia. CSIRO Publishing, Collingwood, Victoria. (Compact Disk and User Guide).

Spain AV. 1969. A new genus and two new species of arboreal Oppiidae (Acari: Cryptostigmata) from New Zealand. Pacific Insects 11: 155-163.

A Trichy Mite in Need of a Trim

June 7, 2013
Neotrichozetes from rainforest canopy in Queensland

Neotrichozetes from rainforest canopy in Queensland

I received a request for information on neotrichy in oribatid mites from a colleague this morning. I wasn’t able to answer it with any authority, but it did remind me of this interesting oribatid mite in the genus Neotrichozetes. ‘Neo’, of course, means ‘new’ and ‘tricho’ is Greek for ‘hair’, so if I were forced to generate a common name for this mite, I suppose I might try the ‘New Hair Mite’. Perhaps not, though, as this would imply a hypothesis that the hairs are new editions to the proper number of hairs a mite should have (the state of having the correct number of hairs is called holotrichy). Neotrichozetes is probably neotrichous, most of its apparent close relatives have no more than 14 pairs of notogastral setae, but there is as yet no robust phylogenetic hypothesis to support this tricky interpretation.

Zetes, for those who may be wondering, was a winged being and a son of the North Wind (Boreas) and Oreithyia, a young lady who made the mistake of wandering too far from home. Many mite genera end in ‘-zetes‘, which seems to come from the Greek ‘zetetes’ or ‘searcher’ and I assume is related to Zetes, the Argonauts and their quest for the Golden Fleece. Perhaps ‘Hairy Canopy Wanderer’ would be a better common name.

Out of the box: A can of lice, good lice, naked middle thirds, and the hideous truth

October 19, 2012

Phthiracarus borealis (Trägårdh, 1910) = Louse + Mite + of the North

I’ve recently been looking at a bunch of ‘bug blogs’ and trying to assess them so I could make a statement about the health of bugbloggery for an upcoming symposium. One of the things that has struck me so far is that, although at the start the spirit may have been willing, the current blog is often weak. Many of the once interesting bug blogs that I have found seem to have run out of steam. If they haven’t posted in more than a year, I’ve been calling them ‘moribund’, but then I realised that here I haven’t posted since July. A quarter moribund? Well, I often feel even worse then that, so I guess I can’t complain if I am being quarter-hoisted by my own petard.

Mesotritia nuda (Berlese, 1887) = Middle + third + naked

So, here’s a mini-post, mostly just to keep from sliding into moribunditry, but also to try and work out one of those arcane problems that keeps me up at night – devising common names for obscure mites that no one has ever seen. In terms of existential angst, this must surely rank among the more absurd, but it is part of my job. I could just shoot from the hip, but I take even the more absurd aspects of my job seriously. I’ve blogged about this problem in other posts, but it hasn’t gone away, so here’s a current example: Box Mites. Being a ‘box mite’ is more a grade of evolution than a taxon – the ability to pull the legs into the body and shut the box has obvious advantages when a predator is trying to grab you by the leg and has evolved several times. The mechanism has been studied in some fascinating papers (e.g. Sanders & Norton 2004), but the authors have wisely never gone beyond the generic ‘box mite’. Unfortunately, Box Mites have done very well over the eons they have been around and acarologists have been giving them lots of obscure Greek and Latin derivative names for almost as long.

Atropacarus striculus (CL Koch, 1835)  – I hesitate to say what this may mean

Unfortunately, my scheme to use the Latin binomials as the source of my ‘common names’ has acquired an itch: the most diverse group of box mites belong to two superfamilies with names from the Greek for ‘lice’ (phthir) and ‘mite’ (acar), the Phthiracaroidea and Euphthiracaroidea, or ‘Louse Mites’ and ‘Good Louse Mites’.  There are mites that live like lice in the hairs and feathers of their hosts, but these aren’t them. The juveniles of box mites burrow in decaying plant material and the adults wander around the soil looking for each other and more decaying leaves and needles into which to lay their eggs. I don’t know what Perty was thinking in 1841 when he erected the genus Phthiracarus, but perhaps he was feeling itchy. Well, lousy name or not, even these mites have also been subjected to interesting studies of the box-making mechanism (e.g. Schmelzle et al. 2010) without wandering past the ‘box mite’ meme. So, I think I will draw my line in the sand at ‘box mite’ and try to summon forth names from the genus or species with which to adorn the box. So far, though, I must say I’m not having much luck. Take Atropacarus striculus as an example. I can’t find any root for ‘striculus’, but perhaps it refers to a stricture. I suppose the area where the legs are withdrawn may look strictured. Unfortunately, all box mites have a similar ‘stricture’. The generic name is also obscure. Perhaps from the Latin for hideous, terrible or cruel (atro-), but then why the extra ‘p’ before acarus? It’s times like these that I’m just glad I can still afford decent Australian wine. I think it is time I sought some inspiration there.

Faculifer sp. – a mite that infests the feathers of Australian doves

How small are mites: the Full Stop Test

May 19, 2012

8 Oribatid mites scaled to a 12 pt Times Roman period (0.5 mm dia.)

Recently The BugGeek posed an interesting challenge: “Can you talk to 10-year-olds about science?” I found this especially interesting because, as an acarologist, I find it difficult to explain the study of non-pest mites to people of any age or educational level. Usually when asked my occupation, I just say ‘I’m a scientist’ or, if among university types, ‘a biologist’ or ‘I work on bugs’. Other than with voluble taxi drivers, this usually proves satisfactory. Sometimes (usually under the influence of alcohol) I do try to explain to strangers the excitement I feel about the diversity of intricate morphologies and amazing behaviours exhibited by mites. But in my experience, if you have a party that has been going on for too long, then I am just the person you need to send even the most couch-bound inebriate scratchingly on their way.

A few years ago, though, I was asked to try and explain mites to 2nd Graders. I decided that the critical information was size – if I could explain how small mites were to an 8 year old, then I’d have a chance. I played around with a how many mites would your foot-print cover (a number too large even for a government deficit) and a penny, but even a penny can hold about 7000 of the smallest mite in the picture above and even in a large poster the mites are too small to see. I finally settle on a Times Roman 12 pt period, conveniently 0.5 mm in diameter. Times Roman and similar serif fonts are those most commonly used in publications (the little feet make a sort of dotted line for the eye to follow while reading) and every sentence ends in a full stop. What could go wrong?

Well, the good news is the 2nd Graders liked the pictures of the mites. The bad news is that ‘period’ does not compute in the 8-year-old mind. We tried inverting the background so that the period was black and the background white (which involved several hours of cleaning up black speckles), but ‘what’s a period?’ proved too great a hurdle. Oh well, it still makes a nice poster.

 

On Mites, Roofs & Jargon: Tectoribates

April 6, 2012

A Roofed Roamer from aspen litter under the January snow

The search for the origin of Oribatida has made some significant progress thanks to a number of classicists and oribatologists and after I’ve tracked down one last reference, all will be revealed. In the meanwhile, in a comment on the last post, James Trager pointed out that ” a better translation for Tectoribates would be either thatch roamer or roof roamer (roofs having once been mostly made of thatch)”.  This hypothesis is supported by the OED, which gives the origin of words like ‘tectiform’ (=roof-shaped) from the Latin ‘tectum’ (=roof). Additional support comes from Gordon Gordh’s and David Headrick’s excellent A Dictionary of Entomology (ADE, 2001 CABI), who point out that ‘tectiform’ is used to describe insects like cicadas that hold their wings roof-like in repose and also from Donald Borror’s handy Dictionary of Word Roots and Combining Forms (1971, Mayfield Publishing Company) that gives ‘tect-‘ as arising from the Latin and Greek for roof. This raises a number of problems though. First, my Tectoribates species are neither arboreal (so not roof mites) nor from grasslands (so thatch would be misleading), nor is any structural feature like thatch or a sloping roof. Second, acarologists have their own definition:  tectum (pl. tecta) – any shelf-like projection of the cuticle.

Acarologists often go their own way on terminology, and this is especially true of oribatologists. As a recently reconverted oribatologist (after a quarter century pursuing other types of mites), my pet peeve with the oribatid jargon is ‘sensillus (pl. sensilli)’ – used for the motion-detecting seta that emerges from a cup-like receptacle on the prodorsum (the spiky, club-like structures on the image above). All the rest of animal morphology uses the neuter form ‘sensillum (pl. sensilla)’ for a sensory seta or other sense organ. ‘Sensillus’ causes no end of confusion and snide comments when a literate, but non-oribatological, referee gets a paper. However, in defence of this non-conformity, it is worth noting that ADE gives ‘sensillum’ as being derived from the Latin ‘sensus’ (=sense), a masculine noun, and so the oribatologists may hold the high ground here.

On further study, this also seems true of ‘tectum’, or at least there is more too it than an A-shaped roof. Cassel’s Latin Dictionary (1968, Wiley) gives ‘tectum’ as the substantive of ‘tego’ the verb ‘to cover’ and exemplars of usage including burying, protection by a shield, and to conceal. The last two would seem to go to the heart of the tecta of oribatid mites: most such structures are designed to shield or cover the legs or other parts of the body where a nasty predator might try to gain a foothold. In the picture above you can see a variety of such tecta including the wing-like pteromorphs that cover the legs, the pedotecta at the base of the legs, the tutoria* (from the Latin to guard or protect) protecting the outer sides of legs I , and the median lamellae (from the Latin for a small plate) covering the tops of legs I. Nature must be very red in others’ teeth and claws for an oribatid mite.

Looking down on lamellae roofing the prodorsum

In Tectoribates the lamellae are unusually well developed and I suspect that Antonio Berlese may have been thinking ‘roof-like’ when he coined the genus in 1910. So, I’m going with Roofed Roamers and my thanks to James.

*tutorium, tutoria (not tutor as the spellchecker would have it)

Going batty: What’s in a name?

February 10, 2012

Pterochthonius angelus: Literally 'Wing Earth Angel'

Last year I got what I thought was a strange request. The people on my project who have to deal with the public were finding it difficult to explain why they needed to sample soil mites on people’s land. They suggested that people might be more responsive if I would give the mites names. I replied that I had already given them names – the Latin binomials – and if they would ‘Speak the speech, I pray you, as I pronounc’d it to you’, they had all the names they needed. But no, it seems that scientific names come trippingly not, on the tongue, and make most landowners uncomfortable or downright suspicious. Of course part of that may be that I tend towards my own idiosyncratic pronunciations. I may confuse scientists whose first language is not English (e.g. Pinus always sounds like a pine-us from me), but they still seemed good enough for media and landowners. But no, they asked for common names, please, just like birds and plants and if I didn’t do it, they would coin their own.

Synchthonius crenulatus - Fused-soil crenulate?

Well, I’m not one to make another’s job harder than it has to be, but unfortunately although there are common names for a few mites – mostly pests of one sort or the other – soil mites mostly go about their business with no one the wiser. So what to do? Well, since I work in a bureaucracy, first up was a protocol. Rule One was that, all else being equal, the common name should be based on the scientific name. Rule Two, that inequality being rife, the name should be reasonably descriptive of the morphology, ecology, or behaviour of the mite. Hence our Pterochthonius angelus at the top became ‘Angel-winged Soil Mite’. I thought that was pretty good – and probably pretty much what Antonio Berlese was thinking when he made it the type species of his new genus in 1913 (before that it was in Cosmochthonius – so God knows what he was thinking then). But I quickly hit a snag as with the clunking and obscure Synchthonius van der Hammen, 1952. This probably refers to a fusion of some of the lateral platelets, but I’m just guessing here. Still, maybe ‘Crenulate Soil Mite’ will do. But then came the first real impasse.

Camisia biverrucata - Nightgown two-warted

Behold Camisia biverrucata (CL Koch, 1839) – The Double-warted Nightgown Mite! Now that was fun and descriptive. When von Heyden proposed Camisia in 1826 my guess (I think I’ve become psychic) is that he was thinking the thick waxy coating of cerotegument was rather like a nightgown covering the mite.  Camisia is Latin and old French for a shirt or nightgown from which Middle English derived ‘chemise’ (and later Romance languages gave us the shorter camisole), so von Heyden certainly may have been daydreaming of nighties. The two ‘warts’ on the bum are diagnostic. Everyone at the Museum had a good laugh at this one and then I sent it on. My colleagues in public relations, however, were not amused. They appealed to me: ‘imagine trying to explain a “warts and nightgown mite” to a landowner’! Bugger, just when this exercise in popular nomenclature was getting more fun than frustrating! Hence Rule Three: no names too icky, too easily misconstrued, or potentially rude. So, we now have the ‘Twin Butte Nightgown Mite’ (its centre of abundance is around the town of Twin Butte).

Oribatula - Mountain-roamer-little

Well I lost that battle, but not the war: there are at least 7 other species of Camissia in Alberta. Unfortunately, they tend to have names meaning ‘spiny’, ‘double-thorned’, and ‘horrid’. I’d better start thinking of descriptive euphemisms. But there are other problems to coming up with common names and the Oribatula above is a good example. The Suborder Oribatida has a lot of generic names with similar roots, from Oribata Latreille, 1806, an obsolete genus. For example, species of Oribatula, Zygoribatula, Tectoribates, and Oribatella are common and diverse in Alberta.

Oribatella jacoti Behan-Pelletier, 2011 - Jacot's Little Roamer

No one is sure where the ‘oribat’ in Oribatida comes from, but one hypothesis is that it is from the Greek ‘oro’ referring to a mountain (as in ‘orogeny’) and ‘bat’ for ‘one who walks or haunts’. So, oribatid mites are ‘mountain roamers’? Well I guess it is possible. One could also translate ‘ori bata’ as the Latin for ‘mouth approval’, but that seems too weird even for an acarologist. ‘Bat’ can also mean a bramble in Greek and these mites do have a lot of spines, and ‘oro’ is Italian for gold, so maybe ‘thorny gold’ was the inspiration? I like that, but only because I just made it up out of the ether.

Propelops alaskensis - Alaskan Darkeye

So, with ‘Oribata’ unresolved, I’ve had to punt and went for ‘Roamer’: the probably undescribed species of Oribatula above is now officially the ‘Field Roamer’ – common in fields, croplands, and open grassy areas. Zygoribatula are ‘Yoked-Roamers’, Oribatella ‘Little Roamers’ and Tectoribates ‘Shelf Roamers’, but is there a better solution? Google tells me that there is a lizard in New Guinea named  Emoia oribata Brown, 1953, and an Australian spider named  Tegenaria oribata  Simon 1916, and even music called Ori Bata (the Ori beat?). Maybe ‘Oribata’ does mean something logical? Perhaps someone out there in the ether can help and offer me a better translation?

The Macromite Before Christmas

December 24, 2010

Water-skating Homocaligus adorned with Roynortonella pustules

The winter solstice (adorned with a full lunar eclipse on an almost clear night here in Edmonton) is several days past and my brief Albertan ‘mid-winter’ holiday season has just commenced. In Australia the first month of summer is almost over – Australia begins its summer on the first day of December, presumably out of the usual nonconformity or some other reason that was never clearly explained to me – but their summer solstice is just past and it is also the holiday season (with snow in the mountains, but otherwise warmer than here). Celebrating the longest night of the year makes a certain sense. Although I still have 4-5 months before green returns to the landscape, I can optimistically assume that the sun will be shining longer and longer each day, even if it is on clouds that are dumping snow on me, and eventually the winter will end, at least officially. So, in the spirit of my holiday season, I wish my readers, wherever they are and whatever their holiday or not, a happy Christmas and productive, healthy, and intellectually stimulating New Year.

An undescribed, but checklist making, Annerossella from Queensland

Over the last few years I have gotten into the habit of tarting up one of my mites for a Christmas card. This year I picked an unidentified Albertan species of Homocaligus – one of the two genera of the raphignathoid family Homocaligidae. This mite is a festive bright red in life and skates over the shallow margins of lakes among emergent vegetation and aquatic mosses. Eggs are probably laid on vegetation as in Annerossella knorri Gonzalez, a homocaligid described from the leaves of water lettuce (Pistia stratiotes) near Bangkok, Thailand. I suspect it is a predator, perhaps of the springtails (Podura aquatica) that hop along in this habitat. I once kept an undescribed Australian species of Annerossella in a small aquarium, but other than watching it skate across the water, I was unable to add anything to the knowledge of its ecology (at about 0.5 mm in length, it is difficult to observe). However, I did make one of my early coloured SEMs of the mite and posted it on the Mite Image Gallery at the University of Queensland. Much to my surprise this was the first record of the family in Australia and my friend Bruce Halliday, putting aside his doubts about the validity of ephemeral web publications, cited the image in his Mites of Australia, a checklist and bibliography (1998, CSIRO Publications). Interestingly, the image at the top of a species of Homocaligus is probably the first record of the family from Alberta.

A pustule from the gymnodamaeid Joshuella agrosticula at 40,000x

Although festive enough for the holiday in itself, I thought the Homocaligus needed more adornment. The pine cone-like bulbs on the mite are cerotegumental pustules from another mysterious Albertan mite, Roynortonella gildersleeveae (Hammer, 1952). This mite used to reside in the genus Nortonella Paschoal, named after the great oribatologist Roy A. Norton. Unfortunately, in 1908 a certain Rohwer had already used Nortonella for a genus of tenthridinid sawflies; thus, the name was preoccupied. I suggested the new name as a replacement that was in keeping with the author’s original intentions. Like other members of its family (Gymnodamaeidae), the surface of the adult mite has scattered fields of strange and intriguing Bucky Ball-like pustules. The pustules arise as the cerotegument dries after the adult moult in what must be some interaction between microfibers and wax. Their elaborate form and species-to-species variants keep me, if not tied to a particular belief in the nature of the Universe, at least still amazed by how rewarding the study of even the smallest parts of Nature can be.

For more on Homocaligidae and Gymnodamaeidae see:

Fan Q-H. 1997. The Homocaligidae from China, with description of two new species (Acari: Raphignathoidea). Entomol. Sin. 4: 337-342.

Gonzalez RH. 1978. a new species of mite on water lettuce in Thailand (Acari: Homocaligidae). International Journal of Acarology 4:221-225.

Walter DE. 2009. Genera of Gymnodamaeidae (Acari: Oribatida: Plateremaeoidea) of Canada, with notes on some nomenclatorial problems. Zootaxa 2206: 23–44.

Wood TG. 1969. The Homocaligidae a new family of mites (Acari: Raphignathoidea), including a description of a new species from Malaya and the British Solomon Islands. Acarologia (Paris): 11: 711-729.