As I wrote in the article that accompanied that photograph, the ladybug then does something remarkable: it becomes a bodyguard. It hunches over the wasp and defends it against predators and other species of parasitic wasps that would try to lay their eggs inside the cocoon. Only after the adult wasp emerges from its cocoon does the bodyguard ladybug move again. It either recovers, or dies from the damage of growing another creature inside of it.

How parasites turn their hosts into zombie slaves is a tough question for scientists to answer. In some cases, researchers have found evidence suggesting that the parasites release brain-controlling chemicals. But the wasp uses another strategy: there’s a parasite within this parasite.

Continue reading “Parasitic Wasps Infected with Mind-Controlling Viruses” →

Here are two recent stories about viruses. They started out alike, and ended up very differently.

In October, a woman in Guinea died of Ebola, leaving behind two daughters, one of them two years old, the other five. A relative named Aminata Gueye Tamboura  took the orphaned children back to her home in northwest Mali–a 700-mile journey. Tamboura didn’t know it then, but the younger girl, named Fanta Conde, was infected with Ebola as well. For three days, they traveled on buses and in taxis as Fanta grew ill, developing a scorching fever and a perpetual nosebleed. Soon after arriving in Mali, she died.

Yet Tamboura never became infected with Ebola. Nor did Fanta’s sister or her uncle, who also made the trip. Nor did anyone else who shared the buses and taxis with Fanta, or who encountered Fanta elsewhere on her doomed journey. After Fanta’s death, the entire country of Mali braced for a devastating outbreak. But the outbreak never came.

Continue reading “How The Measles Virus Became A Master of Contagion” →