Laboratory studies were conducted to evaluate rates of increase of both the two-spotted spider mite, Tetranychus urticae Koch and its predaceous mite, Phytoseiulus macropilis (Banks), on five different host plants. Mass rearing of this predator on the two-spotted spider mite on bean plants was also investigated during three months rearing periods. All tested host plants were found to be susceptible to the two-spotted spider mite infestation. Also, the highest increase of the predator popul­ation was noticed when both the prey and the predator reared on bean plants.