Cover photograph (Copyright © 2006, American Society for Microbiology. All Rights Reserved.): Section through the abdomen the Oregon R strain of Drosophila melanogaster, stained with an antibody that recognizes enterococci and cross-reacts with other bacterial species (red) within the alimentary tract. The section is also stained with 4`,6`-diamidino-2-phenylindole (blue) to highlight the nuclei of Drosophila cells. Bacteria are abundant in the crop (round red speckled mass in the lower right), in the rectal ampulla (red speckled ellipse on the left), and in the ventriculus (red speckled masses in the middle). Enterococci were found to be an invariant component of the Drosophila flora, establishing the fly as a tractable model for studying native microbe-microbe and microbe-host interactions involving this genus. (See related article on page 1565.)