During a study 20 hydrophilid beetle species and 2,457 individuals of beetles belonging to 4 genera: Cercyon, Cryptopleurum, Megasternum and Sphaeridium were collected. On the surface of the bodies of 59 beetles (2.40% of the beetles collected) belonging to six species, 174 cases of phoresy [55 deutonymphs of Uropoda orbicularis (Müller, 1776) and 119 pedicels without deutonymphs] were observed. New hydrophilid beetle carriers of phoretic deutonymphs of U. orbicularis are given. Most mites were carried by Sphaeridium species. The population dynamics of both groups of arthropods was also studied. Most cases of phoresy were recorded in May and in the second half of July. However, phoretic deutonymphs were not present on the body surface of hydrophilid beetles throughout the whole period of this study.
Of 31 species of coprophagous beetles from the following families: Aphodiidae, Geotrupidae, Scarabaeidae, individuals of 25 species carried deutonymphs of Uropoda orbicularis (Müller, 1776). The mite's preferences for attaching to specific parts of an insect's body were determined by examining 4,318 specimens of beetles from the following families: Aphodiidae, Geotrupidae, Scarabaeidae, Hydrophilidae and Histeridae. We recorded 14,507 cases of phoresy (5,822 deutonymphs and 8,685 of pedicels without mites) on 2,056 insects. Elytra and the third pair of legs were the areas most frequently occupied by the mites. The mite's preferences for attaching to specific parts of an insect body are reported for the first time.