A new species and new records of Tetranychidae (Acari: Trombidiformes) from Saudi Arabia, with a key to world species of Mixonychus Ryke and Meyer

The spider mite genus Neotetranychus Tragardh is reported for the first time from Saudi Arabia (SA) based on N. longisetus n. sp., collected from Heliotropium arbainense (Boraginaceae). The new species is described and illustrated from the adult female, and three species, Mixonychus (Bakerina) aculus (Chaudhri), Paraplonobia (Anaplonobia) harteni (Meyer) and Sonotetranychus daleae (Tuttle and Baker) (Acari: Tetranychidae) are reported as new to the mite fauna of SA. Mixonychus (B.) aculus (Chaudhri) is re-described and illustrated based on adult female, collected from an exotic mesquite species from Mexico and Caribbean, Prosopis juliflora (Sw.) DC. (Fabaceae). Moreover, the species, Evertella orissaensis (Prasad) n. comb., is moved from the genus Mixonychus Ryke and Meyer to the genus Evertella Meyer and Mixonychus (Bakerina) ganjuis (Qian, Yuan and Ma) n. comb., is moved to the subgenus Bakerina Chaudhri from the subgenus Mixonychus. A key to the world species of the genus Mixonychus is also provided. Additionally, legs chaetotaxy of all known species of the genus Mixonychus is given.