Zombie fungus hijacks fruit flies' brains

Abstract

A zombie fungus that infects fruit flies may take control of them by releasing chemicals into their brains. Parasitic fungi usually infect a host then control its behavior in a way that gives the fungus a better chance of spreading to more victims. Now Carolyn Elya at the University of California, Berkeley, has observed this kind of fungus infecting fruit flies in her back garden. Getting it to attack fruit flies in the lab allowed her team to learn more about how parasitic fungi operate, because fruit flies are so well studied--they are used in labs around the world. The fungus, called Entomophthorci muscae, kills fruit flies in four to seven days, Elya's team has found. The animals appear to behave normally until the final day, when their gait becomes shaky and they won't fly even if prodded. Instead, they start heading up any vertical object and soon stop walking altogether. The flies then extend their proboscis and use it to glue themselves to whatever surface they are on. Over the next 10 minutes, they slowly spread their wings in little bursts. Then, a few hours before sunset, they die in a characteristic pose. It was this pose that drew Elya's attention to the infected wild flies in her backyard. After the flies die, the fungus starts sprouting from their bodies.