The first alarms about the sudden widespread disappearance of honeybees came in late 2006, and the phenomenon soon had a name: colony collapse disorder. In the two years that followed, about one-third of bee colonies vanished, while researcherstoiled to figure out what was causing the collapse. A study published last week in the Proceedings of the National Academy of Sciences surmises that there may not be a single pathogen involved but a collection of culprits. What have entomologists and beekeepers learned in the last few years of dealing with the crisis? We asked May R. Berenbaum, an author of the study, and other experts for an update