Studies show that Blattisocius mali (Acari: Blattisociidae) is highly effective in controlling insect pests infesting potato tubers under storage conditions. However, its ability to control mite pests infesting bulbs has not been tested so far. Since some edaphic predatory mites are very promising biocontrol agents against acarid mite pests infesting stored lily bulbs, we hypothesized that the edaphic predatory mite B. mali might be highly effective against acarid mite pests infesting flower bulbs. This study aimed to investigate whether B. mali could control the mould mite Tyrophagus putrescentiae Schrank (Acari: Acaridae) infesting lily (Lilium L.) and tulip (Tulipa L.) bulbs. Typically, lily bulbs are stored with peat at a lower temperature, so we tested whether altering accessibility of B. mali to T. putrescentiae by adding peat in lily bulbs could affect the predator-prey interaction. In lily, B. mali was released on infested bulbs, stored either without peat or with peat, in a predator-prey ratio of 1:40, while in tulip, it was applied to infested bulbs stored without peat in a predator-prey ratio of 1:40 or 1:20. All the experiments were performed using plastic containers containing three lily or tulip bulbs at 26 °C temperature in darkness, optimal condition for both the predator and prey. Each treatment was replicated twelve times for each experiment. The mean numbers of T. putrescentiae motiles found at the end of trials were significantly lower in the treatments, lily bulbs stored without peat, lily bulbs stored with peat, tulip bulb with predator-prey ratios of 1:40 and 1:20 (98.7, 190.0, 184.0, and 38.0 motiles/container, respectively) than those in the respective controls (1718.7, 2753.3, 2139.7, and 920.7 motiles/container). Similarly, the mean numbers of T. putrescentiae eggs were significantly lower in both treatments of tulip bulbs (26.3 and 9.7 eggs/container, respectively) than in respective controls (744.7 and 33.7 eggs/container, respectively), while these did not vary significantly between treatment and control in lily bulbs. The effectiveness values of B. mali in controlling T. putrescentiae were 93.75% and 91.98% in lily bulbs stored without peat and with peat, respectively, while these were 92.70% and 95.01% in tulip bulbs with predator-prey ratios of 1:40 and 1:20, respectively. This study suggests that B. mali was highly efficient in diminishing the population of T. putrescentiae in both stored lily and tulip bulbs.