Distribution of beneficial bacteria on nashi and apple flowers using honey bees

Abstract

Honey bees have previously been shown to disperse biological control agents of fire blight (caused by Erwinia amylovora), such as Erwinia herbicola [Pantoea agglomerans] Eh252, onto apple flowers. In this study we investigated whether bees could also effectively disperse Eh252 onto nashi (Pyrus pyrifolia) flowers. After providing lyophilized bacteria to two bee hives in a commercial nashi orchard (New Zealand) for seven days, 83% of the flowers were colonized with Eh252. After removal of bacterial inoculum, 95% of newly opened flowers were still colonized, indicating transfer of beneficial bacteria from flower to flower. In a similar experiment carried out three weeks later in an apple orchard, the rate of colonization of apple flowers by Eh252 in the first three days was even greater.