The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pest species devastating many horticultural and ornamental crops and fruit trees. In the present study, a field strain was collected in January 2001 and has been selected for sixteen years with acequinocyl. The resistance ratio calculated from the LC50 of eggs and adults was 191- and 4,237-fold, respectively. The laboratory-selected acequinocyl resistance (LSAR16) strain was screened with 11 acaricides for cross-resistance. The detoxifying enzyme activities and quantitative real-time PCR analysis were performed in the LSAR16 strain. Crossing experiments revealed that LSAR16 strain was inherited maternally, incompletely dominant and monogenic. Most importantly, we identified two new point-mutations at mitochondrial cytb from acequinocyl resistant T. urticae.

• Sung Il Kim(Department of Plant Medicine, Chungbuk National University, Republic of Korea)
• Won Jin Kang(Department of Plant Medicine, Chungbuk National University, Republic of Korea)
• Yeseul Choi(Department of Plant Medicine, Chungbuk National University, Republic of Korea)
• Hyunah Kim(Department of Plant Medicine, Chungbuk National University, Republic of Korea)
• Bueyong Park(Crop protection division, National Institute of Agricultural Science, Republic of Korea)
• Hyun Kyung Kim(Department of Plant Medicine, Chungbuk National University, Republic of Korea)
• Hyun-Ha Koo(Department of Plant Medicine, Chungbuk National University, Republic of Korea)
• Gil-Hah Kim(Department of Plant Medicine, Chungbuk National University, Republic of Korea)