Cover photograph (Copyright © 2004, American Society for Microbiology. All Rights Reserved.): Larva of the greater wax moth, Galleria mellonella. The advanced innate immune response of this insect makes it an excellent model host for studying bacterial, fungal, and nematode infection processes. (For an article in this issue dealing with the use of G. mellonella to examine the regulation of the mrf gene cluster of the entomopathogen Photorhabdus temperata in vivo, see page 611.)