Scheloribates distinctus Mihelčič , 1964 – a species of mite ( Acari : Oribatida ) new to fauna of Poland and new records of three rare species

A new to fauna of Poland oribatid mite species (Scheloribates distinctus) and new localities of three rare species (Protoribates pannonicus, Punctoribates ghilarovi, Oppia nitens) are recorded from old compost heap in Łomianki near Warsaw, Mazovia Region, Poland.


INTRODUCTION
There is over 40 000 named species of mites (it is estimated that there is even 1 million unnamed species) and about 11 000 of described oribatid mites (Walter and Proctor 2004), with ca.500 species occurring in Poland.It is almost half of European oribatid species (Olszanowski et al. 1996).Recognition of oribatid mites' distribution is still unsatisfied as well (Niedbała 2004).
Windrows of compost are hot-spots of soil biodiversity in local scale and can be very promising in faunistic research (Rozkošný 1982, Ødegaard andTømmerås 2000).High richness of species and high abundance of individuals, are both much larger in compost heaps than in surrounding soil (Walter and Proctor 2004).Thereby probability of discovery of new or rare species is relatively high there.

METHODS
Mites were extracted from sample of over 20 years old garden compost, consisted of kitchen and garden vegetable litter, in January 2004, in Łomianki near Warsaw.For extraction a Macfadyen apparatus was used (Krantz 1978).Specimens were cleared in lactic acid before determination and examined under a compound microscope using the half-covered cavity-slide method of Grandjean (Niedbała 1980).Keys to oribatid mites of Gilyarov andKrivolutskiï (1975) andWeigmann (2006) were used for species identification.Sex of specimens was not determined due to objective obstacles in sex designation in oribatid mites (Niedbała 1980).

RESULTS
The following rare species was found in examined material:
The faunistic knowledge of the analyzed species is sparse.Also ecological data are insufficient.However, it was confirmed, that all these species are dwellers of habitats with higher contents of dead organic matter (i.e.marshes, litter) and O. nitens even prefer those habitats (Weigmann 2006).It remains unresolved how these species got into compost: by natural dispersion or by artificial introduction with wastes.