First record of Parasitus americanus ( Berlese , 1905 ) and Cornigamasus ocliferius Skorupski & Witaliński , 1997 ( Acari : Mesostigmata : Parasitidae ) from Slovakia

Two species of Parasitidae, Parasitus americanus (Berlese, 1905) and Cornigamasus ocliferius Skorupski & Witaliński, 1997 were found for the first time in Slovakia. Parasitus americanus is a cosmopolitan species, which was found in several cemeteries and in a botanic garden in Bratislava. Almost all records of C. ocliferius are from Poland except for one record from Egypt. Cornigamasus ocliferius was found in decomposed plant material in Western and Central Slovakia and in bird nests in Western and Eastern Slovakia; part of the material was previously published as Cornigamasus lunaris (Berlese, 1882) and is revised here.


Introduction
The mites of the family Parasitidae are free-living predators which can be found in soil habitats.Some genera of this family, for example Parasitus and Cornigamasus, frequently occur in ephemere habitats as compost, manure or decaying hay.The greatest diversity of the family Parasitidae is in the Palearctic, but several species are known from North America (Hennessey and Farrier 1989) and from the Southern Hemisphere (Karg and Schorlemmer 2009).The deutonymphs of P. americanus can be phoretic on insects, and this species seems to be very frequent in agricultural soil (Hyatt 1988).On the contrary, C. ocliferius is a very rare species with only a few known records, mostly from decaying hay.
Mites were collected from soil, leaf litter, bird nests and compost samples.For the studied localities see the map (Fig. 1).Mites were collected by 2 methods-substrate samples and pitfall traps.Pitfall traps consisted of a plastic cup (3 cm diameter × 8.5 cm deep) buried up to its rim in soil and partly filled with 10% formaldehyde.Traps were exposed from April to October 2014 and were emptied at monthly intervals.Mites were extracted from substrates to 70% ethylalcohol solution by Berlese-Tullgren funnels.Mites were separated from other soil arthropods collected using a Leica EZ4 stereomicroscope, and the material was processed to yield microslides using the chloralhydrate Swan's medium.Photographs were taken using a Leica DM 2500 compound microscope with a Canon EOS 70D Camera Module (EOS Utility v. 2.13.20.0).We used bright-field microscopy as well as DIC microscopy to take the photographs.Voucher specimens are deposited in the Slovak National Museum with catalog numbers SZ 10 885 and SZ 10 886 and in Acarological Collection in Department of Zoology, Faculty of Natural Sciences, Comenius University.

Results
Our specimens of P. americanus fit with the redescription by Hyatt (1988).This species is closely related to Parasitus fimetorum (Berlese, 1904) but the adults can be easily recognized according to following characters: the first pair of sternal setae of females is not closer to each other than second pair of sternal setae (Fig. 2), the form of the endogynium (Fig. 3), the epigynium bears near its apex a pair of small anteriorly directed teeth and 1 small secondary tip (Fig. 4), the movable digit of the male's chelicera bears only 1 big tooth (Fig. 5), and the corniculi of male are entire (Fig. 6).As noted by Hyatt (1988), we cannot separate with certainty the deutonymphs.
Cornigamasus ocliferius is similar to and often misidentified with C. lunaris.We used the identification key provided by Witaliński (2014).The deutonymphs can be easily distinguished from other Cornigamasus species because they have only 9 pairs of setae on the opisthonotum (Fig. 7).The adults can be separated according to a lacking ambulacrum on tarsus I (Fig. 8).Males have only 1 small conical main spur on femur II (Fig. 9), and the opisthonotum of females bear only 2 pairs of stout setae (Fig. 10).

Discussion
Parasitus americanus is a cosmopolitan species, found mainly in agricultural soils.Deutonymphs are frequently phoretic on beetles.It was described from Paraguay (Berlese 1905) and is widespread in South America (Athias-Henriot 1980, Postner 1953), USA (Morlan 1952),  the Pieniny Mountains in southern Poland, and only few kilometers from Slovakia, so we assume that this species is also in Slovakia; now we have confirmed it.
Skorupski and Witaliński (2014) stated that C. ocliferius is a very rare species and only a few specimens of both males and females are known.Despite that, we found a relatively large population of this species, and the revision of the material deposited at the Department of Zoology, Comenius University in Bratislava showed that C. ocliferius is not as rare as we assumed.Most of the records of C. ocliferius from Poland are from rotten hay, and only 1 record is from decaying litter and fodder of a rabbit (Witaliński 2014).However, we found this species in high abundance in a decomposed plant material and also in bird nests.

Figures 2
Figures 2-6.A comparison of P. americanus on the left side of each figure and P. fimetorum on the right.2. Sternal shield of female with sternal setae.3. Endoynium of female.4. Epigynium of female.5. Digitus mobilis of chelicera of male.6. Corniculi of male.Scale bars: 100 μm.

Figures 7 -
Figures 7-10.A comparison of C. ocliferius on the left side of each figure and C. lunaris on the right.7. Opisthonotum of deutonymph.8. Tarsus I of female.9. Leg II of male.10.Opisthonotum of female.Scale bars: 100 μm.