Field tests with acaricides for the control of Tetranychus urticae Koch on strawberries.

Twenty-three pesticides were evaluated in 18 trials in 1974-79 for the control of red spider mite (Tetranychus urticae) on strawberries in areas in England where strains of mites resistant to the organophosphorus pesticides and dicofol were known to occur. The organophosphorus pesticides chlorpyrifos and triazophos continued to give good control at most of the sites. Demeton-S-methyl, dioxathion and omethoate used at only two of the sites significantly reduced the number of mites. Pirimiphos-methyl, dimethoate and quinalphos used at only a few sites did not give a significant control. The carbamates aldicarb, thiofanox, formetanate and methiocarb usually gave significant control. Of all the pesticides tested, cyhexatin consistently gave the best control The specific acaricides amitraz, dienochlor, dinobuton, fenbutatin oxide, propargite and quinomethionate were usually effective. Dicofol gave much more variable results than in earlier trials, probably because of resistance. [ABSTRACT FROM AUTHOR]