As suggested by Kawashima (2006), the most abundant Tetranychidae was Tetranychus sp. as a pest in persimmon orchards. The observatory orchards were selected 16 in total, 2 from Gurye, 2 from Gwangyang, and 2 from Suncheon in Jeonnam Province and 3 from Jinju, 4 from Sacheon, and 3 from Sancheong in Gyeongnam Province. Number of mites in 100 persimmon leaves were observed from each orchards nearly every ten days. Careful rearing of the mites sample collected from the four observaory persimmon fields at which the mite had occurred the most seriously among 16 fields and results from taxanomical identification process indicated that the species was identified Tetranychus urticae. Maximum number of T. urticae reached to 436 on 27 June at Jeongdong, Sacheon, 108 on 1 August at Sinann, Sancheong, 406 on 26 June Okgok, Gwangyang, and 509 on 15 June Muncheok, Gurye. When the number reached to more than 400 mites, the persimmon leaves changed from clear yellow dots, to pale yellow, and to grey in the backside. An experiment was conducted to control T. urticae and to select highly active miticide in persimmon orchards in Jinju and Sacheon. Spiromesifen 20SC and acequinosyl 15 SC were effective.

• Bu-Keun Chung(Divison of Plant Environment, Gyeongnam Agricultural Research and Extension Servicies)
• Mitsuhiro Kawashima(Department of Agricultural Biology, Andong National University)
• Chuleui Jung(Department of Agricultural Biology, Andong National University)