The subgenus Oligonychus (Oligonychus) Berlese (Acari, Prostigmata, Tetranychidae), diagnostic keys to world species, and taxonomic notes

The present study provides the morphotaxonomic-based identification of the world species of the subgenus Oligonychus (Oligonychus) Berlese. In this lieu, five diagnostic keys were erected to identify Oligonychus (O.) species belonging to five subgroups; smithi, peruvianus, subnudus, aceris, and coffeae. In addition, taxonomic notes on some Oligonychus (O.) species, either briefly described or closely related, were provided, and intraspecific variations were highlighted.