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

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.

A Big Mite & A Bad Dream for Moose

May 18, 2013
Business end of Winter Tick male Dermacentor albipictus (Packard, 1869)

Business end of Winter Tick male Dermacentor albipictus (Packard, 1869)

In a Comment under the previous post, George demanded “Give us new mites! We like mites!”. Well, okay, but I’ll give you one of the few mites that I loathe, a tick. Here’s a view of the subcapitulum of a Winter Tick, Dermacentor albipictus (Packard, 1869). Sadly, ticks are mites and real mites – members of the Parasitiformes. They also tend to be relatively large – a fully engorged female Winter Tick looks like a big, black marble and is about as big as any mite gets (~1.7 cm). This individual was pretty big, about 7 mm long, but a male and so not interested or even able to engorge.

Dorsum of male Winter Tick - both ornate and festooned

Dorsum of male Winter Tick – both ornate and festooned

Male hard ticks (Ixodidae) have their upper side (dorsum) covered by a large, leathery plate called a scutum. In a female, the scutum is much smaller and no hindrance to her body swelling – both stretching and growing new cuticle (without moulting – very rare in arthropods) – as she fills with blood and then eggs. Both do have pretty silvery and brown patterns, though, which makes them ornate ticks, and a square, tooth-like pattern on the posterior margin of the body called festoons. Both also have the diagnostic characters of ticks such as the retrorse teeth on the hypostome (the projection between the palps in the top picture) used to anchor the capitulum (‘little head’) in the skin of a host, slicing chelicerae, a hexapod larval stage and a cluster of pits, pockets and sensory setae on the tarsus I called Haller’s Organ.

Haller's Organ on tarsus I of Winter Tick

Haller’s Organ on tarsus I of Winter Tick

One reason I loathe ticks (and also terrestrial leeches) is that they are so blood-thirsty and avariciously desirous of slicing into your skin and regurgitating their secretions into the wound. A tick bite is invariably painful, at least once the tick has gone, and prone to infection. The infections are often delivered by the tick itself – after mosquitoes, no other arthropod group is such a good vector of disease. The feeding by the ticks themselves can be devastating both from paralyzing salivary secretions (as with the related Rocky Mountain Wood Tick or Australian Paralysis Tick) or the general irritation and loss of blood. Moose in Alberta often are covered with tens of thousands of Winter Tick resulting in hair loss, loss of condition and death. The grey, ratty and emaciated moose are called ‘Ghost Moose’ and are a sad sight.

Larva (6-legged stage) of Ixodes holocyclus

Larva (6-legged stage) of Ixodes holocyclus

I think that is about all I can stand to say about ticks on a fine Saturday morning. If you would like to learn more about Winter Tick and Ghost Moose, then there is no better place than Bill Samuel’s book:

Bill Samuel. 2004. “White as a Ghost: Winter Ticks & Moose” Federation of Alberta Naturalists.

If you want to learn more about ticks, try the Manual of Acarology 3rd Edition. If you aren’t in too much of a hurry and would like to learn all kinds of interesting (and often disgusting) facts about how ticks and other mites go about their lives, then I can tell you that the 2nd Edition of Mites: Ecology, Evolution & Behaviour was submitted to the publisher at the end of April. Meanwhile, I’ll leave you with a light micrograph of the subcapitulum of a male Winter Tick. You can compare it to the coloured-SEM at the top and decide which you would prefer to visit your dreams.

Winter Tick male subcapitulum

Winter Tick male subcapitulum

There are no Big Mites and the Big Prawn is in Limbo

April 20, 2013
The Big Prawn in happier days

The Big Prawn in happier days

It is a sad truth that there is no Big Mite in Australia, nor indeed anywhere in the World so far as I know. There is a Big Ant, at least as an abstraction, in Broken Hill and a Big Mozzie in Hexham and even a not-so-itzy Big Spider in Urana. But no Big Mite. Once, though, Ballina could boast of a Big Prawn.

The Big Prawn today - just a shell

The Big Prawn today – just a pallid shell

Alas, the Australian sun sent the Big Prawn  to a barbie and it came out looking much like a 60 tonne white elephant. Then its raison d’être  closed and the 20-something Prawn was condemned to demolition by the Ballina Shire Council in 2009. Thanks to the reluctance of its owner, popular demand and a promise to refurbish by Bunnings Warehouse the shell lingers on in a vacant lot awaiting its resurrection. I hope Bunnings comes through with its promise. The Big Prawn was always my favourite stop on the north coast of New South Wales and the opening slide to my lecture on eating arthropods. I suppose I’m suffering from nostalgia, and certainly from homesickness in several ways, but I prefer a giant pink prawn to any number of giant pink squid.

Giant Squid on top of Questicon, Canberra

Giant Squid on top of Questacon, Canberra

Well, actually, I prefer calamari to prawns when it comes to eating invertebrates, but Paul Hogan never said he’d ‘throw another prawn on the barbie’ anyway.

The Big Prawn, in no way a shrimp

The Big Prawn, in no way a shrimp


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