神澤氏葉蟎及二點葉蟎對葡萄果實之為害

Abstract

The major spider mite species found in the vineyards in Tungshi of Taichung County was Tetranychus urticae Koch. T. kanzawai Kishida was rarely found. This was probably affected by the neighboring crops. Spider mites were found on grape clusters in eight out of the ten surveyed vineyards. Ten percent of grape clusters in average were infested with spider mites. However, the mite density on cluster was low, averaged 0.63 only per cluster. The percentage of grape berries infested was 0.4%. Inoculating T. kanzawai artificially onto grape clusters, the mites either died before developing into next instar or run away when the berry was not ripe. After the ripeness of berry, the mite could feed, develop, and reproduce on the berry.