A revision of the family Ameroseiidae (Acari, Mesostigmata), with some data on Slovak fauna Author Masan, Peter Institute of Zoology, Slovak Academy of Sciences, Dubravska cesta 9, 845 06 Bratislava, Slovakia uzaepema@savba.sk text ZooKeys 2017 2017-09-29 704 1 228 http://dx.doi.org/10.3897/zookeys.704.13304 journal article http://dx.doi.org/10.3897/zookeys.704.13304 1313-2970-704-1 111A101E74054C408F51693957A64D97 CB39FF8EFFA2FF8CFFBFFFA9FF94FF8B 1149838 Ameroseius callosus Masan , 1998 Plate 3 Ameroseius callosus Masan , 1998: 648. Type depository. Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia. Type locality and habitat. Slovakia, Podunajska Nizina Lowland, Brunovce, in floodplain forest, on fruiting body of willow bracket fungus, Phellinus igniarius ( Basidiomycota , Hymenochaetaceae ). Published material from Slovakia . Trnavska Pahorkatina Wold: Brunovce Village ( Masan 1998 ). New material from Slovakia . Ipeľska Kotlina Basin: 1 ♀ - 23. 6. 1997 , Ipeľske Predmostie Village , Ryzovisko Forest , willow-poplar flood-plain forest ( Salici-Populetum ), wood-destroying fungus Trametes sp., altitude 130 m , leg. P. Masan . Podunajska Rovina Flatland : 4 ♀♀ - 5. 10. 2004 , Bratislava Capital , Mlynske Nivy Settlement , park with willows and poplars, individual collecting on fresh wood-destroying fungi, altitude 135 m , leg. P. Masan ; 3 ♀♀ - 14. 6. 2015 , Bratislava Capital , Cunovo Settlement , wood-destroying fungus ( Phellinus sp.) growing on old walnut tree ( Juglans regia ), altitude 130 m , leg. P. Masan . Povazsky Inovec Mts. : 1 ♀ - 17. 5. 1997 , Hradok Village , Hradocka Dolina Valley , broad-leaved deciduous forest, individual collecting on wood-destroying fungi, altitude 450 m , leg. P. Masan . Trnavska Pahorkatina Wold : 1 ♀ - 18. 5. 1997 , Brunovce Village , Vah River (alluvium), degraded willow-poplar flood-plain forest ( Salici-Populetum ), individual collecting on wood-destroying fungus Trametes sp., altitude 170 m , leg. P. Masan . Remarks. Ameroseius callosus shows a close resemblance to Ameroseius fungicola , except for some characters of the dorsal shield (sculpture and relative length of setae). Although A. callosus may be easy and reliably separated from A. fungicola , several pieces of evidence show that this species could be only a polymorphic form and synonym of A. fungicola . This hypothesis should be confirmed by further comparative studies, based also on laboratory rearing and molecular analyses, to establish their correct systematic status. Polymorphism has been mentioned in a few mesostigmatic mites of the families Ascidae , Laelapidae , Macrochelidae and Parasitidae .