| abstract | The group of the heteromorphic deutonymphs (or hypopi) of the astigmatic mites (Acari) phoretically associated with fleas of mammals and birds, is reviewed. The authors describe Psyllopus gerbillicola n.g. and n.sp. (Acaridae) from hypopi found from Gerbil-fleas from North Africa. Up to now 31 species of these hypopi have been recorded, they belong to 12 genera and 3 families of mites. The corresponding adults are known for only 7 species, i.e. Acarus siro, A. farris, A. nidicolous, Rhizoglyphus echinopus, Michaelopus corticalis, Histiostoma feroniarum and Psylloglyphus parapsyllus. This phoretic association has been observed in 76 species of fleas belonging to 43 genera and 9 families. This type of phoresy is particularly frequent in nidicolous fleas, it is rare or completely lacking in the fleas living in the fur of the rodents. A list of all the known species of phoretic hypopi and of their hosts is given. |