Taxonomy of the Genus Bryobia Koch (Acari: Tetranychidae): Reconsideration of Subgenera and Updated Species Groups

The present study aimed to revise the subgeneric divisions of the genus <i>Bryobia</i> based on persistent characteristics and to propose species groups in each subgenus to further ease the identification of species. As a result, only three subgenera, based on literature, are recognized, viz, subgenus <i>Bryobia</i> Koch (duplex setae present on leg tarsi III-IV), subgenus <i>Allobia</i> Livschits and Mitrofanov (duplex setae absent on leg tarsi III-IV), and subgenus <i>Lyobia</i> Livschits and Mitrofanov (duplex setae present only on leg tarsus III). The analysis based on morphological characters and available COI sequences on the GenBank database did not resolve the phylogenetic relationship of <i>Bryobia</i> species, and likewise, no support could be found for the proposed subgeneric divisions. The species in each subgenus were further categorized into species groups based on the position of the fourth pair of dorsocentral setae <i>f</i>1, viz, three species groups, <i>praetiosa</i>, <i>osterloffi</i>, and <i>neoephedrae</i> in subgenus <i>Bryobia</i>; three species groups, <i>pritchardi</i>, <i>abbatielloi</i>, and <i>deserticola</i> in subgenus <i>Allobia</i>; and three species groups, <i>eurotiae</i>, <i>sarothamni</i>, and <i>rubrioculus</i> in subgenus <i>Lyobia</i>. Furthermore, detailed notes are provided on eight <i>Bryobia</i> species which were described by Meyer, having morphological characteristics of both the tribes Bryobiini and Hystrichonychini. The generic status of two bryobine species, <i>B</i>. <i>pseudorubrioculus</i> Smiley and Baker and <i>B</i>. <i>tuttlie</i> Smiley and Baker, is also discussed and considered as <i>species inquirendae</i>.