A new distribution map is provided for Tetranychus pacificus McGregor. Acari: Tetranychidae. Hosts: polyphagous, including melon (Cucumis melo), soyabean (Glycine max), cotton (Gossypium spp.), common bean (Phaseolus vulgaris), stone fruit (Prunus spp.) and grape (Vitis vinifera). Information is given on the geographical distribution in Asia (Japan) and North America (Canada, Alberta, British Columbia, Mexico, USA, Arizona, California, Idaho, Oregon, Utah and Washington).