In a long-sought step toward building a safer mosquito, researchers have infected the insects with bacteria that sabotage their malaria-causing parasites.

Researchers would like to use Wolbachia bacteria to keep malaria parasites from thriving inside a mosquito. In theory, a mosquito with the right bacterial infection could bite people without delivering the parasites that cause malaria.

Wolbachia naturally infect insects from butterflies to cockroaches — but not mosquitoes. Years of effort have established Wolbachia in mosquitoes that spread dengue fever (SN: 7/14/12, p. 22), but the Anopheles species that carry malaria have been very difficult to infect.

At last, after a team led by Zhiyong Xi of Michigan State University in East Lansing injected Wolbachia bacteria into thousands of embryos of the mosquito Anopheles stephensi, one female caught a lingering case and started a laboratory line of infected offspring.