description
First, the literature of the last two decades on nutritional effects of host plants on spider mites isbriefly reviewed. Second, experiments are described that subjected micro-propagated apple trees tofour different leveis of each macronutrient N, P and K. Spider mites ( Tetranychus urticae Koch)feeding on leaf disks of these plants were checked for their developmental time, egg production andlongevity. Plant analysis revealed that the concentration ofN, P and K corresponded to the respectivetreatments.