Abstract
Susceptibilities to five chemicals on two different strains of Phytoseiulus persimilis were compared. One was introduced from University of California, Riverside (UCR, susceptible), the other from “Biologische Bundesanstalt für Land- und Forstwirtschaft, Institut für biologische Schädlingsbekampfung” Darmstadt, Federal Republic of Germany, in 1984 through the kindness of Dr. Sherif A. HASSAN (DAS, resistant). Susceptibilities to fenitrothion, carbaryl and chinomethionat were low in the DSA strain. However, susceptibility to acephate was the same and that to permethrin was very high in both strains.
