抄録
On the main islands of Japan and in Taiwan, the spider mites Tetranychus kanzawai and T. urticae (green and red forms) are major pests on vegetable crops. The present study revealed that the dominant spider mite species injurious to vegetables in Okinawa, located between the main islands of Japan and Taiwan, differed from those in the two regions, providing important and fundamental information for controlling spider mites in Okinawa. T. okinawanus was the most dominant species throughout Okinawa with the broadest host range, even though the species has been regarded as a non-pest to date. T. piercei, which has similarly not been treated as a vegetable pest, was the second most dominant species with respect to frequency of occurrence and host range. T. kanzawai and T. urticae (green form) were comparable in the frequency of occurrence to T. piercei in the northern part of Okinawa (Okinawa Islands), whereas they were scarce in the southern part (Sakishima Islands). As other less-dominant species, T. ludeni, T. neocaledonicus and T. pueraricola were found infesting several vegetable crops. T. urticae (red form) was not found in this study.
