Susceptibility of Tetranychus kanzawai Kishida and Phytoseiulus persimilis Athias-Henriot towards insecticides used in the tea fields of Shizuoka Prefecture, Japan

Abstract

We investigated the chemical susceptibility of Kanzawa spider mites (Tetranychus kanzawai Kishida) and colonized exotic predatory mites (Phytoseiulus persimilis Athias-Henriot) collected from tea fields in Shizuoka Prefecture from 2019 to 2021.

The chemicals that caused in a corrected mortality rate of ≥90% in adult females and eggs of T. kanzawai across all populations were abamectin, milbemectin, acequinocyl, bifenazate, ethoxazole-pyrimidiphene, cyenopyrafen, cyflumetofen, and acynonapyr, out of the 16 chemicals tested.

Out of the 32 chemicals tested, profenofos, emamectin, abamectin, milbemectin, tebufenpyrad, pyridaben, tolfenpyrad, etoxazole, pyrimidifen, and fluxametamide were highly toxic to P. persimilis. In contrast, dinotefuran, clothiazinine, pyrifluquinazone, etoxazole, BPPS, chlorfenapyr, lufenuron, methoxyfenozide, acequinocyl, bifenazate, cyenopyrafen, cyflumetofen, pyflubumide, cyantraniliprole, chlorantraniliprole, cyclaniliprole, flubendiamide, flonicamide, and acinonapyr were less toxic to P. persimilis.

Moreover, acequinocyl, bifenazate, cyenopyrafen, cyflumetofen, and acinonapyr were highly effective against adult females and eggs of T. kanzawai, while having little negative effects on adult females P. persimilis. In contrast, spraying the three chemicals, emamectin, tolfenpyrad, and fluxamethamide, that are not applicable to T. kanzawai and highly toxic to P. persimilis in tea fields may lead P. persimilis population decreasing, while T. kanzawai increasing.