Wolbachia are well known bacteria because they often kill developing males of all manner of creatures, from nematodes to crustaceans. Karyn Johnson and her colleagues from the University of Queensland in Brisbane, Australia, now report that Wolbachia offer fruitflies some protection against diverse and deadly RNA viruses.
They compared the survival of two strains of fruitfly infected with Drosophila C virus with that of the same species infected with both this virus and Wolbachia pipientis. The bacterium seemed to delay virus-induced mortality by the same amount of time that it delayed the accumulation of virus particles in the flies, implying a causal link. Johnson's team then tested two other viruses in the same way, and also found that Wolbachia delayed mortality.