Infection divides two wasp species

Giving antibiotics to tiny wasps to cure them of a sex-related disease reveals the best evidence yet that infections can help make new species, say researchers in New York.

A Nasonia wasp, about 3 millimeters long, injects an egg into a fly pupa. (c) Werren

Each of two closely related species of wasps in the genus Nasonia carries two separate strains of Wolbachia bacteria, notorious saboteurs of insect reproduction, report Seth Brodenstein and his colleagues at the University of Rochester.