Velvet Mite

[TonyT]

Checking on BugGuide this appears to be a Long-legged Velvet Mite.
Extracted from leaf litter below Oak trees. Mounted dry.
Top image shows the entire mite; middle image is @ 20x; 3rd image is a crop fromn image 2,
This mite appears to have only 2 hairs, in the dorsal central part of the body which is lacking those black "dots",
I will try to get a more magnified image of those "dots".

[mrsonchus]

Interesting and good images. Perhaps a few of the 'dots' may be removed, with or without that part to which they are attached, and examined perhaps with an oil-mountant and coverslip on a compound 'scope's higher and transmitted illumination - I refer to oil to place the sample pieces into and then coverslip over, not to an oil-immersion objective's use.
They clearly have structure, a closer/higher-resolution look would be interesting - I wonder what they are?

I think your image/s have turned out very well and contain details to stimulate further enquiry?

[tgss]

I agree with mrsonchus - the images are good and interesting. I assume your interest in the "black dots" is because you have not found a reference to a species with this sort of surface texture as a normal attribute? Certainly my quick search didn't turn up anything like this. Is this a case of "fleas on fleas"?
Tom W.

[TonyT]

Thanks for the comments, a couple more images:
top: head end taken with a 60x Nikon MPlan objective
bottom: close-up of the region level with the eye.
The black dots appear to be highly modified hairs, pyramidical with a few longitudinal spikey ridges; similar structures on the legs but more elongated

[mrsonchus]

Hmmm, the plot thickens...... They have a look also of some type of spore-cases, but their apparently ordered orientation 'along' the legs in particular suggests otherwise? More detail/research is needed! Great images and subject.

[mrsonchus]

Success!
I found a paper re a recently identified new species of velvet mite, Here's the PDF.....

I think these structures are known as, in this paper at least, "scobalae" - there's a superb image of such scobalae around the eye-region of said newly discovered species. (see PDF link)

A snip from within image,

velvet mite scobalae.JPG (51.96 KiB) Viewed 2536 times

A search for 'scobala' or scobalae' is a tricky one! Not much comes up of any use at all, then I saw this in the list of search reply snippets,

scobalae definition.JPG (28.75 KiB) Viewed 2536 times

It would seem that scobalae are "non-sensillary setae", setae being, after another search, 'hairs'.....
Further-on those spikey projections upon these un-hairlike scobalae/setae are 'spicules' (dorsal in this case?). The above linked-to paper uses the number of these spicules upon the scobalae as a taxonomic feature it seems... Fascinating!

You never know - your may be a new species! I'd like to thoroughly check the 'long-legged velvet mite' ID, but it certainly looks like it, two front legs used to feel-around in the abscence of antennae.... Non-segmented body, 8 legs not 6..... what an interesting track from your great images!

[TonyT]

John,
Thanks for finding all that info. Non-sensillary indicates not a sense organ. However, they must have an important function whatever it is.
I took an image with my Olympus 100x Oil Splan +1.25x intermediate tube + 2.5x projection eyepiece on my BH2; saw more detail, seems a good subject for a SEM.
In life these scobalae stand upright, in this image they are beneath a coverslip and thus not orientated upwards. They vaguely remind me of certain lepidoptera eggs.

[mrsonchus]

Simply fascinating, and a great image - I suspected they were squashed-down but no problem there! Nice level of detail - the number of spicules may be of taxonomic value too, as it is said to be in that excellent PDF of the new species discovered.

May I ask what set-up you're using? A BH2 (can't get a better base than that I'd say) and are you using transmitted or incident illumination? I think the images are very impressive certainly considering the irregular and untreated/processed natue of the specimen - primarily the scobalae.
A really excellent and interesting and inspiring post! Not my area (I say that so often these days); must try to get back to some Botanical work myself, things are quite difficult at the moment.

Thank you so much for following-up with the further investigation - it's always the same with microscopy I find, whatever the subject.... As soon as the ever-enquisitive mind feels a tiny prickle, the learning and discovery rockets exponentially with a will! Congrats, nice post and work.

[Javier]

Impressive images and very interesting information.