Due to the limited surface area of covered bean cultivation, there is only a limited amount of practical experience in this area. However, where Amblyseius swirskii is applied, it appears to be easier to combat thrips than when A. cucumeris is used. Preventative introduction in a clean crop appears to have little point. Although the flowers of a bean crop produce pollen, very little of this pollen is available for the predatory mites; it remains inside the flowers, in contrast with the pollen of sweet pepper and aubergine flowers. Should preventative introduction become necessary, this should in any event take place by means of slow-release bags. Effects of A. swirskii on whitefly have been mentioned, but it appears that parasitic wasps are also necessary alongside predatory mites in order to achieve the required effect.