DRIFTING BEHAVIOR OF HONEY BEES (APIS MELLIFERA CARNICA POLLMAN, 1879) IN THE EPIDEMIOLOGY OF AMERICAN FOULBROOD

The drifting of honey bees often occurs in apiaries where numbers of hives are kept close together and it is an important vector in the spreading of honey bee diseases. It occurs in high numbers, frequently and over long distances. Within this work, it was investigated whether drifting might play a role in the epidemiology of American foulbrood. To determine the presence and the number of P. larvae spores in samples of honey, pollen and honey sacs, three different methods were used: modified Ritter-Kiefer (1993) method, Columbia blood agar test (Plagemann, 1985) and catalase tests (Haynes, 1972). Although the level of drifting within the colonies with clinical symptoms of AFB was slightly higher than the one within the colonies without clinical symptoms, AFB infection did not significantly influence the drifting frequency. Even when drifting was compared between two groups of young bees at the age of orientation flights, AFB infection did not significantly influence the level of drifting. However, as the level of P. larvae spores detected both in the pollen and honey stored in the hives, as well as in the pollen found on the legs of the bees from infected colonies, was significantly higher compared with the one in colonies with no clinical symptoms of AFB, it can be concluded that drifting plays a role in the spreading of AFB, especially during the orientation flights of young bees.