青森県のリンゴ園におけるナミハダニに対する殺ダニ剤の効力の推移

抄録

Bioassays have been conducted since 2003 to assess the efficacy of acaricides against the two-spotted spider mite Tetranychus urticae, collected from apple orchards in Aomori Prefecture. The current status of acaricide efficacy was evaluated and compared with its efficacy in the past. Milbemectin, bifenazate and propargite maintained high efficacy in most populations. The efficacy of cyflumetofen, cyenopyrafen and pyflubumide has reduced in recent years in some populations, and the data suggested that T. urticae exhibited cross resistance to these three acaricides. The efficacy of spiromesifen has become insufficient in most populations. Spirodiclofen, a new acaricide, demonstrated high efficacy against T. urticae eggs.