The overall objective of this project is to develop a technique for the dissemination of biological control organisms (BCO's) by bumblebees, for the protection of the inflorescences in apple and pear against fire blight (Erwinia amylovora). Pear cultivation is an important sector in the Flemish fruit both in terms of cultivation area (approximately 9080 ha, 430 companies) and economic value (EUR 120 million). Export is of crucial importance. Among the new markets are fire blight-free countries such as China which want a guarantee that the fruit from fire blight come free areas. Therefore the use of BCO will's against fire blight are focused primarily on the defined blight-free areas in Flanders (350 ha within two years). Second, the new combat technique of fire blight will warden applied to companies in the recent past were faced with fire blight infections (a potential of 400 ha and 600 ha apple pear). A third group of orchards where the BCO technique pretty quickly input will find the recently planted new plots apple and pear (about 100 ha per year).