Potential of Monitoring for Some Species of Eriophyid Mites by Using Suction Devices Developed for Capturing Small Insects in Tea Fields

We tried monitoring the seasonal occurrences patterns of several species of mites in tea fields by using small suction devices driven by dry cell batteries, which were developed for capturing Pseudaulacaspis pentagona larvae, from April to November 2010. The devices captured Tetranychus kanzawai, phytoseiidae mites and two species of eriophyid mites: Acaphylla theavagrans, and Calacarus carinatus. The number of captured individuals of the two species of eriophyid mites was larger. Simultaneously, after replacing the trap cartridge in the device, we collected 20 tea leaves weekly from areas near the place where the capturing device was set, and investigated the density of each mite species on the collected leaves. We compared the densities of the mites and the number captured by the device. For the two species of eriophyid mites, A. theavagrans, and C. carinatus, the patterns of seasonal occurrence revealed that the number of mites captured and their density on leaves were almost synchronized. Moreover, a significant positive correlation was found between the number of mites captured and their density. Although the device had some problems in outdoor durability, the findings suggested that it is suitable for monitoring of eriophyid mites in tea fields.