Abstract
The basic ecological characteristics of Tetranychus okinawanus Ehara, a new spider mite speciesf rom Okinawa Islands, were examined and compared with those of other tetranychid mites. The mites develop more quickly and lay more eggs at young ages than other typical colonizing speciesuch as T. urticae and T. kanzawai. Thus, T. okinawanus has the highest intrinsic rate of natural increase among tetranychid mites reported so far. The mites lack diapause capacity and do not survive well at low temperatures. However, the polyphagous nature and the extremely highreproductive capacity of T. okinawanus may potentially enable it to be a serious pest in controlled environments such as greenhouses.
