Mansour, F., Dept. of Entomology, ARO, Newe Ya’ar Regional Experiment Station, Haifa, P. O., 31999, Israel

Dosage mortality data for 12 pesticides were determined with females of an insecticide-susceptible strain of the carmine spider mite, Tetranychus cinnabarinus (Boisd.), by the slide dip method; for four of the pesticides which are specific acaricides, also the Munger cell method was used. The LC50s ranged from 0.00078% to 0.041%, with the synthetic pyrethroids being more toxic than the specific acaricides. There were no differences in results between the two assay methods. Four synthetic pyrethroids that were very active against T. cinnabarinus in laboratory tests were examined in an unsprayed apple orchard for their effect on the population density of spider mites. An upsurge of tetranychid mites was noted 4 weeks after a single application © 1988, Springer Science + Business Media B.V.. All rights reserved.