Archive for the ‘Uncategorized’ Category

An Empty Shell

April 25, 2015
Epicrius male gnatho

Under the business end of a male sejid mite

Macromite has been more than a bit of a slacker this last year or so, both scientifically (only one paper published – a record low) and in social media. I blame the latter on Facebook which has eaten all my social media impulses and regurgitated them into several-weekly postings on the fauna and flora accessible to my point-and-shoot camera. Alas, that does not include mites.

Epicroseius outside moult

The cast skin (exuviae – always plural, like clothes, so do not make the abomination of ‘exuvia’)

Also, I now live in the near outback: far from microscopes and internet access. My modem connection is both slow, expensive and unreliable and not conducive to rambling on about mites. That is a drag, but sometimes late at night the bandwidth is accessible and I am not asleep and that is true this post-ANZAC Day. Ergo, I would like to make a point about moulting in Mesostigmata that I don’t think  I have ever published: Mesostigmata moult forwards!

Epicroseius inside moult

Inside the glove: where the chelicerae and palps are extracted

Well, at least this species in the reasonably early derived (I would say ‘primitive’, but I know I would be stoned by the cladistically correct) Sejidae, or at least what I think is best attributed to an undescribed species of Epicroseius, moults this way. I know because I was able to culture it by feeding it nematodes (its’s progenitors came from a sample of wood mulch on the University of Queensland St Lucia campus). I think spiders moult the same way, but at least some members of the Acariformes go their own way. Possibly this may be phenological support for the lack of sister-group status between the two superorders of ‘mites’.

Epicroseius lateral

Epicroseius all grown up and undescribed

I do think that splitting the skin above the gnathosoma and other limbs is normal for Mesostigmata, but this hypothesis really needs to be tested against a variety of lineages. Meanwhile I will be wandering the back roads of Pie Creek, Qld, and learning to appreciate the larger charismatic microfauna including things like Clown Bugs – the habitat of Coreitarsonemus, the mites that eat the stink glands of leaf-footed bugs, or so it is asssumed!

Clown Bug Amorbus robustus 4th instar PieCk 2March15

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.

 

Anystis: the race is sometimes to the swift

February 13, 2014

 

An anystid (possibly an Anystis) eating a scale insect (Photo Geoff Waite)

An anystid (possibly an Anystis) eating a scale insect (Photo Geoff Waite)

I was reading an essay on political cant by George Orwell yesterday, “Politics and the English Language” (1946), at Project Gutenberg Australia*. As one exercise he rewrote, into political obfuscation, a famous and lyrical passage from the Bible:

“I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favor to men of skill; but time and chance happeneth.” (Ecclesiastes 9:11 King James Version)

Almost always Orwell makes his points clearly and with passion. I now feel a bit chastised at my writing and terrified of using ‘dying metaphors’, ‘verbal false limbs’, ‘pretentious diction’ and ‘meaningless words’. I especially don’t want to use meaningless words.

That same day, I received a request for help with the etymology of a genus of mites, Anystis von Heyden, 1826. I was at a loss, my books were of no help, and Google failed. I’ve previously posted on the psychic perils of reading Karl von Heyden’s mind. Anystis seemed to be without meaning.

This morning, though, after a long walk taking poor pictures of macropods and beetles, the verse from Ecclesiastes bobbed-up in my memory along-side Anystidae – a family of famously swift runners. Common names include ‘whirligig mites’ in North America and ‘footballers’ in Australia (don’t ask me to explain Australian Rules Football, but even a few minutes of watching will convince you that the players in colourful jerseys spin around with abandon much like the mites). Could Anystis be a name, not from the Latin or Greek, but of something or someone fast in the past?

My friend Bruce Halliday (at what is left of the CSIRO at Black Mountain) had sent on a list of von Heyden genera and from my limited knowledge, his names indicated an interest in Greek history. For example, Cunaxa  a genus of predatory mites may be a reference to the Battle of Cunaxa reported on by the Greek mercenary Xenophon.

With the proper modifiers, Google now came to the rescue with a passage from a delightful book on ‘Running through the Ages’ by Edward Seldon Sears: “The Spartan runner Anystis and Alexander the Great’s courtier Philonides both ran 148 miles (238 km) from Sicyon to Elis in a day.” (Sears 2001). This seems to be derived from Pliny in his Natural History, who thought this run (1305 stadia) was more impressive than the better-known dash of Philippides from Athens to Sparta (1140 stadia) to report on the battle of Marathon.

I take this race as strong inference of what von Heyden was thinking when he proposed the genus Anystis. Anyone who has watched these mites must be impressed with their speed, and although the ancient Anystis exhibited both speed and stamina, I now feel some confidence that I am using the generic name in a non-meaningless way.

References:

* http://gutenberg.net.au/ebooks03/0300011h.html#part47

von Heyden, C. H. G. 1826. Versuch einer systematichen Einteilung der Acariden. Isis, 18, 608-613.

Sears, E.S. 2001. Running through the Ages. McFarland: Jefferson, NC.

Merry Christmas 2013

December 22, 2013

Christmite_2013

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.

Photo Magnet: Antennolaelaps Appreciation

June 25, 2011

Ventral view of gnathosoma of Antennolaelaps sp.

What do Antennolaelaps, Emmylou Harris, Catherine Deneuve, FDR, The BVM, and assorted ladies with musical instruments, ladies in informal attire (or not attired), and a couple of strange dudes have in common?

Results of a Google Image Search

It must be the colour scheme, but at least no algorithm has confused this attractive member of the Mesostigmata with Darth Vadar. That would only be appropriate for members of the genus Darthvaderum Hunt, 1996, a member of the Oribatida.

Hat tip to Myrmecos.

Of Knots & Worms Not: Gordialycus

May 23, 2010

In the last posting I mentioned some long and lean mites, but not having any good images of them, I used an interesting near-insect to test the 500 pixel width effect. In a month or so, however, I will be teaching about some of these mites (at The Ohio State University Acarology Summer Program) and I’m taking advantage of a very dreary Long May Weekend to start getting my lectures in order. Since I’m borrowing an image from a paper for my Power Point anyway, I thought I’d tart it up and trial it here.

The mite is the extraordinary Gordialycus tuzetae Coineau, Fize & Delamare Deboutteville and the picture originally composed by my friends Roy Norton, Anibal Oliveira, and Gilberto de Moraes for their 2008 paper reporting this mite, or an indistinguishable relative, from Brazil for the first time. The original image was composed from 3 separate rather low-magnification light-microscope micrographs – that is what it took to capture the entire animal. I’ve simply masked the mite and tarted it up in Photoshop with a less elongate and more mite-looking Speleorchestes species for comparison. The red arrows point to the tiny legs III and IV (just posterior is the genital slit).

Speleorchestes in its full glory - almost a quarter millimetre long

Both Gordialycus and Speleorchestes belong to the enigmatic Endeostigmata – a perhaps paraphyletic basket that includes the most primitive-looking acariform mites. Endeostigmatans are found throughout the World, but are especially prominent in very dry habitats or dry microhabitats within more mesic ones. Both hot and cold deserts (e.g. see the Nanorchestes I’ve posted on before) have more than their share of endeostigmatans. Members of the Nematalycidae are the most worm-like of the group, and Gordialycus by far the longest stretch, but being relatively elongate is normal for the family and not uncommon in other families of Endeostigmata.

 Gordia– is probably from the Greek for twisted or knotted – as in the famous Gordian Knot and –lycus possibly from the Greek for wolf. Since the gut contents of this mite have no solids, and no Alexander has yet come along to cut this not, we have no idea whether or not it is a predator. Haupt & Coineau (1999), however, have a hypothesis about how this mite uses the annulations of minute plates that ring its body to row its way through the deep sands in which it occurs. This particular mite was taken on a beach in Brazil – and deep accumulations of unconsolidated sand are where you will find this mite and its shorter relatives. Since the upcoming International Congress of Acarology is in Recife this August, perhaps the beaches there will be filled with acarologists trying to collect more of these spectacular mites – and maybe a few trying to figure out what they are doing while they worm their way through the sand.

 Species of Speleorchestes can be found on beaches too – but they can be found in a variety of habitats pretty much anywhere – my front yard, for instance. Speleo– probably refers to a cave and –orchestes possibly to dancing. Species of Nanorchestes can jump – as close to dancing as one might expect in a mite – and are tiny (nano-). I can’t remember ever seeing a Speleorchestes jump, but I can’t remember seeing any feed either. Alas, members of the Nanorchestidae also feed on fluids and so their foods are mysterious, although there is one report of a species munching on algae.

References:

 Coineau Y, Fize A, & Delamare Deboutteville C. 1967. Découverte en France des Acariens Nematalycidae Strenzke l’occasion d’aménagement du Languedoc-Rousillon. C. R. Acad. Sci., Paris 265: 685-688.

 Haupt J & Coineau Y. 1999. Ultrastructure and functional morphology of a nematalycid mite (Acari: Actinotrichida: Endeostigmata: Nematalycidae): adaptations to mesopsammal life. Acta Zool., Stockholm 80: 97-111.

 Norton RA, Oliveira AR & de Moraes GJ. 2008. First Brazilian records of the acariform mite genera Adelphacarus and Gordialycus (Acari: Acariformes: Adelphacaridae and Nematalycidae) International Journal of Acarology 34: 91-94.

Inspired by Myrmecos: Parajapyx

May 4, 2010

Parajapyx - another long, lean, post-crustacean

This posting was inspired by Myrmecos, a general lack of inspiration, and just wondering what a 500 pixel wide microarthropod might look like. Although there are some long, lean mites that might be more appropriate, Prolixus forsteri comes to mind, or perhaps the unbeatable long lean acarine, Gordialycus tuzetae Coineau, Fize & Deboutteville 1967 – which looks more like a giant nematode than a worm (for a light micrograph see*), alas, I have no pictures of them.

Really, I’m just tired of shovelling snow (~20 cm today, and it is well into May) and ready to veg out in front of the most recent Circus of the Spineless, so here’s one of my larger contributions, a ~ 3 mm long Parajapyx species from Queensland (where snows are few and far between). Not much seems to be known about these mini-diplurans. The monstrous Heterojapyx (~ 20 mm) make better pets, especially if you enjoy watching them catching collembolans with their posterior pinchers, twisting around their abdomens, and then eating the RSPCAless springtails alive, but are far too large to contemplate for the SEM.

Heterojapyx sp. -one of the largest living dipluran

*Norton RA, Oliveira AR & de Moraes GJ. 2008. First brazilian records of the acariform mite genera Adelphacarus AND Gordialycus (Acari: Acariformes: Adelphacaridae and Nematalycidae) Internat. J. Acarol. 34: 91-94.

A menagerie of microarthropods

April 29, 2009
A selection of mites, springtails, and a Parajapyx

A selection of mites, springtails, and a Parajapyx

I got interested in mites through soil ecology and I’ve yet to lose my amazement that one can find dozens of species of microarthropods living in a few handfuls of decomposing plant matter almost anywhere.  True desert soils usually only have a couple dozen, and there are probably only 5-6 dozen species of microarthropods known from the Antarctic continent, but pretty much everywhere else a handful or two of litter may have a dozen dozen or more.  A couple of years ago a friend who was writing an ecology text asked me for a plate showing diversity in the decomposers, and I made him this.  These mites (mostly), springtails (2), and a more or less insect are all scaled the same and you might be able to faintly make out the 0.1mm scale bar in the middle of the picture.

Evimirus attack

April 27, 2009
Eviphididae from Mars

Eviphididae from Mars

Perhaps only an acarologist would find this image strange, but the curlicues coming out of the peritrematal shields of this Australian species of Evimirus (Mesostigmata, Eviphididae) shouldn’t be there. Well, not unless they drown in alcohol. The large pore on the peritrematal shield apparently has a defensive function and squirts out something that hardens in ethanol. Didn’t do this mite much good, but allowed me a rare flight of fancy.