New species and new record of Tetranychus Dufour from Australia, with a key to the major groups in this genus based on females (Acari: Prostigmata: Tetranychidae)

A new species of spider mite, Tetranychus bunda sp. n., is described and illustrated from Australia. It was found damaging the foliage of Desmodium tortuosum (Sw.) DC. (Fabaceae) in Darwin, Northern Territory. In addition, the geographical range of Tetranychus fijiensis Hirst is extended to include Australia. This species was found in the Northern Territory feeding on frangipani ( Plumeria sp., Apocynaceae), betel palm ( Areca catechu L., Arecaceae) and Macarthur feather palm ( Ptychosperma macarthurii [H. Wendl. ex Veitch] (H. Wendl. ex Hook. f., Arecaceae)). Details of the biology of T. bunda sp. n. and T. fijiensis are given. A key to the major groups of Tetranychus Dufour of the world, based on females, is presented and species known to occur in Australia are outlined.