Oribatida (formerly Cryptostigmata), also known as moss mites or beetle mites are an order of mites, in the "chewing Acariformes" clade Sarcoptiformes. They range in size from 0.2 to 1.4 millimeters (0.008 to 0.055 in).

Oribatid mites generally have low metabolic rates, slow development and low fecundity. Species are iteroparous with adults living a relatively long time; for example, estimates of development time from egg to adult vary from several months to two years in temperate forest soils. Oribatid mites have six active instars: prelarva, larva, 3 nymphal instars and the adult. All these stages after the prelarva feed on a wide variety of material including living and dead plant and fungal material, lichens andcarrion; some are predatory, but none is parasitic and feeding habits may differ between immatures and adults of the same species.

The Oribatida are of economic importance as hosts of various tapeworm species, and by increasing the breakdown of organic material in the soil, in a similar manner to earthworms.

BTW, you can use from this file that attached as PDF.

Thanks Ebrahim. I  downloaded all papers about oribatid in internet, but i  couldnt find the best identification key 

Dear Ito,

Mount your mites in a temporary cavity slide in aqueous glycerine (70% v/v). Store them in vials in ethanol.

There is no 'best' identification key to oribatids on the internet or anywhere else. The reference to the Balogh & Balogh two-volume work that Ibrahim sent you is hard to use, even for experts. Having said that, I started out using the 1973 version of these keys.

The best introductory guide to identification (but only to superfamily)and systematics is Norton, R.A. and Behan-Pelletier, V.M. (2009) Suborder Oribatida. In: Krantz, G.W. and Walter, D.E. (eds.) A Manual of Acarology. Third edition. Texas Tech University Press, Lubbock, Texas, pp. 430–564. The illustrations to morphology are very good and without a  basic understanding of morphological terms you won't be able to use the keys anyway.

Hope this helps. Cheers, Matt 

Thanks @Matt Colloff. Yes, i also use A Manual of Acarology 3rd edition.  Thank you very much.

Thank you Dear Matt Colloff.

I used of your contents.

Dear Ito

If you are interested in working with Oribatida, I will suggest you to take the OHIO mite Summer Program, Soil Mite course, Columbus, Ohio State University, Prof. Hans Klompen.  There are couple of lucid keys in the Internet by David E Walter that you could use.  Oribatida is to mites, what beetles are to Insecta; you will need many different references and notes from many authors and the OSU course is your best start point. 

Dear Ito

The best way to mount oribatid in order to identify is in temporary open slice with lactic acid (1:1) as medium. For conservation propose deffinitive preparation in hoyer are good, but can occured that the specimens broken, the best way for conservation are in alcohol (glass flask).

As all the previous collegues told you the last edition of Acarology (2009) is the book you can find all the information. About the keys, well it depend of the level you want to achive: for family level you can used the book Acarolgy. If you need species level you must seach for another key, mainly a local key (from your region)

Best luck

Dear Ito,

Don't use lactic acid as a temporary mounting medium for examination of mites in cavity slides. Clear and macerate the mites first in lactic acid or  50% aqueous potassium hydroxide and then wash in water (five minutes) and transfer to 70% aqueous glycerol. If you leave the mites in lactic acid on a cavity slide for extended periods they tend to fall to pieces because the connective tissue dissolves. Incidentally, the lucid key Mites in Soil http://www.publish.csiro.au/web_cds_demo/mites/userguide.htm#HowTo) by David Walter and Heather Proctor referred to above does not include keys to oribatids. The Delta key to oribatids by Hunt et al. (1998; cf. link above for reference) is only for Australian taxa, but it is out of 'print'. Cheers, Matt  

Dear Ito,

About slide mounting, I but my mesostigmatid and oribated mites (those have a hard sclorotized bodies) in Lactic Acid for 3-4 days in room temp. and transfere them into the slide, I use Hoyer medium for mounting, so before I but the cover I drop a large amount of media to being sure that the mite won't be damaged.

You can follow and contact Dr. S.G. Ermilov Tyumen State University, Tyumen, Russia. I haven't a personal communication with him, but he has a well publication in oribated mites, I think he would may help you.

You can follow him in Researchgate: Sergey G. Ermilov

Or send him an e-mail: e-mail: [email protected]

Good luck,

Islam  

Thanks and best regards @Matt Colloff, Islam M. Zidan, Natalia Andrea, and Ronald Ochoa.

And I want to say thanks to Ronald Ochoa, I read your journals about Brevipalpus, which was very informative.