Frankliniella occidentalis is the most important pest in greenhouse crops. Successful control of this pest is very difficult. In laboratory and greenhouses studies predator mites Amblyseius swirskii and Amblyseius cucumeris showed a high efficacy used together in control of western flower thrips (83% mortality). Predators used separately were less efficacious against the pest (about 63% mortality). The studies showed neutral interaction of A. swirskii and A. cucumeris populations in control of western flower thrips.