A new species of Parapygmephorus Cross, 1965 (Acari; Heterostigmatina; Neopygmephoridae) phoretic on Halictus quadricinctus (Fabricius, 1776) (Hym.; Halictidae) from Iran

A new species of the genus Parapygmephorus Cross, 1965 (Acari: Heterostigmatina, Neopygmephoridae) is described from Northeastern Iran. A phoretic adult female of Parapygmephorus khorasanicus Hajiqanbar and Khaustov sp. n. was discovered clasping on hairs on the ventral body surface of Halictus quadricinctus (Fabricius, 1776) (Hymenoptera; Halictidae). It is the fifth representative among the known species of the genus Parapygmephorus in the world. Differentiation of new species from other species of the genus is discussed, and a key to known world species is provided.