Two new species of Pachyseius Berlese (Acari: Pachylaelapidae) from Turkey, with a key to the world species

Two new species of the genus Pachyseius are described from leaf litter in Turkey. Pachyseius destitutus sp. nov. is described based on the female, and P. quadrigeminus sp. nov. is described based on the female and male. These species have some uncommon character states for the genus, such as the absence of dorsal shield seta z1, four pairs of setae on the ventri-anal shield, and a male with a holoventral shield. We provide a key to the world species incorporating new information about the genus.