Cover photograph (Copyright © 2008, American Society for Microbiology. All Rights Reserved.): Image of negatively stained nucleocapsids of a polydnavirus from the ichneumonid parasitoid Glypta fumiferanae. Mature virions consist of several nucleocapsids surrounded by two envelopes; the latter cannot be distinguished here because of the detergent treatment used to expose the nucleocapsids. Each nucleocapsid is believed to package more than one and possible many double-stranded circular DNA molecules, but it remains unclear whether each nucleocapsid, or virion, contains the full spectrum of more than 100 genome segments. (Micrograph by Don Stolz.) (See related article in June 2007: vol. 81, issue 12, page 6491.)