Bacteria carried by the fruit flies. Live Drosophila melanogaster flies were immersed in a mannitol medium designed to culture Acetobacter aceti. Bacteria present on and in the fruit flies propagated very rapidly and the medium became opaque within 12 hours. The bacteria were captured on a bacterial filter, fixed, and prepared for SEM. A variety of bacteria may be seen but the bacteria were not identified by microbiological criteria. When transferred by the Drosophila flies onto fruits, the bacteria find a nutrient-rich medium and propagate rapidly, thus spoiling the fruit and making it unfit for human consumption. Drosophila may also spread microscopical plant pathogens. Enhanced SEM. Image width: 9.1 micrometers. Magnification: 10,990x if the image is printed 10 cm wide.