Résumé
The species of the tetranychid mite genus Pseudobryobia are revised mainly based on data published in the literature. Following a survey of the classification history of the genus, emphasizing the changes that occurred in the morphological characters used in its definition, we briefly discuss their relative importance for the genus delimitation. As a result, we provide amended diagnoses for the genera Pseudobryobia and Bryobia and transfer 7 species from Pseudobryobia to Bryobia. Species belonging to the genus Pseudobryobia bear two setae on coxisternal plate II, one pair of tenent hairs on all the empodia and are distributed in the Nearctic biogeographic zone. Conversely, some species previously assigned to the genus Pseudobryobia bear one seta on coxisternal plate II, two rows of tenent hairs on empodia II-IV, and are recorded in the Palearctic and Afrotropical biogeographic zones. These species are transferred to the genus Bryobia. The following nomenclature changes resulting from the revision are proposed: B. (Bryobiopsis) abbatielloi new combination, B. (B.) anacantha reinstated combination, B. (Allobia) bucharica reinstated combination, B. (B.) eurotiae reinstated combination, B. (A.) japonica reinstated combination, B. (B.) neoephedrae new combination, B. (A.) nikitensis reinstated combination. We recognise six subgenera for Bryobia, as previously considered by other authors, and also treat Nuciforaella Vacante (1983) as a junior synonym of Bryobia (Allobia) Livshits and Mitrofanov, 1971. A key to the species of Pseudobryobia is also provided.