A new genus and species of the family Microdispidae (Acari: Prostigmata) associated with Oryctes nasicornis (Coleoptera: Scarabaeidae) and redescription of the monotypic genus Vietodispus Mahunka, 1975

Background: Mites of the family Microdispidae (Acari: Prostigmata: Heterostigmata) are fungivorous, usually living in soil, litter, decaying plant materials, and similar substrates, and adult females have phoretic associations with arthropods, particularly insects. The family Microdispidae is poorly studied, and because of the vague descriptions of most of the genera and species, the taxonomy of this family is in a state of confusion. Previous to this study, more than 109 microdispid species in 17 genera have been described worldwide. Results: In this study, a new genus, Neomicrodispus gen. nov. (Acari: Microdispidae) (type species Neomicrodispus iranicus sp. nov.) is described and illustrated based on phoretic females recovered from Oryctes nasicornis (Coleoptera: Scarabaeidae), which were collected from the forests in northern Iran. Also, the monotypic genus Vietodispus Mahunka, 1975 (type species Vietodispus calcaratus) is redescribed based on its holotype lent from the Hungarian Natural History Museum. The representatives of the family Microdispidae associated with arthropods are reviewed. Conclusions: There are now 18 genera of this family worldwide that are primarily defined by reductions in their morphology. Because of poor description of some genera and species, synonymies or decreasing in systematic ranks may be expected. A review of arthropod associations, provided in this paper, showed that these mites are primarily associated with ants and beetles, where a rich source of various kinds of fungi particles is easily obtained.