Toxicities of some insecticides to Two-spotted Spider Mite, Tetranychus urticae Koch, on Chrysanthemum in Nara Prefecture

Abstract

Toxicities of insecticides for adult females of Tetranychus urticae Koch collected from five chrysanthemum fields in Nara Prefecture were investigated. The corrected mortality rates of bifenazate were 100% in all populations. The rates of acequinocyl and abamectin were higher than 80% in three and four populations, respectively. No significant decrease of susceptibility was found. The rates of milbemectin and emamectin benzoate were lower than 50% in one or two fields, respectively. The rates of cyenopyrafen, pyflubumide-fenpyroxymate, spinetoram were lower than 28.4% in all fields.