Serratia Marcescens, Artificially Contaminating Brood and Worker Honeybees, Contaminates theVarroa Jacobsoni Mite

SummaryUsing Serratia marcescens, microbiological assays have indicated that Vanoa jacobsoni can harbour this indicator bacterium on its body surface and internally. The majority carry from several to hundreds of bacteria per specimen, others have more than 107 cells. Only a few mites fed on brood and worker bees artificially inoculated with the indicator by spray, feeding or injections, had no cells of Serratia. A source of Varroa pollution was not only bacterial inocula but also brood and bees killed by S. marcescens multiplication. Since this ectoparasitic stenophagous mite is easily polluted with Serratia and transmits bacteria from one bee to another, V. jacobsoni can disseminate microbes as a vector to a recipient bee host.