Terrifying Zombie Fungus



The fungus Entomophthora muscae has a survival strategy that's impressive and likely to cause you to lose another meal: it infects and "zombifies" female flies before sending out irresistible chemical signals to drive the male flies into necrophilia. 

By attracting these males to mate with the zombified females, the fungus can be transmitted to the male flies and theoretically has a better chance of further spread. The unfortunate male fly is then eliminated by E. muscae in the same way.

Important in this process is the release of sesquiterpenes, or chemical messages that are synthesized in the female body and sent out as an attractive signal. Based on experiments conducted by researchers, the longer a corpse is dead, the more attractive it is to men. 

"Chemical signals act like pheromones that target male flies and cause them to mate with dead female corpses," says evolutionary biologist Henrik H. De Fine Licht. , from the University of Copenhagen in Denmark. 

When E. muscae infects a female fly with its spores, it begins to reproduce. After about six days, it controls the behavior of the insect, sending it to the highest point possible (on a wall or plant) before it dies. 

The spores of the fungus are then sent off the dead fly in the hope that they will land on another. But as this new study shows, by attracting a male, E. muscae can ensure that it continues on to at least one more host and once again carries its tracks far and wide. The team is using various chemical analyzes and genetic sequencing techniques to determine exactly what the fungus has done, as well as the exposure of male flies to female partners at different stages of infection. 

"Our observations suggest that this is a conscious strategy for the fungus," says H. De Fine Licht. "He's a real master of manipulation - and it's very interesting." Tests showed that female flies that died within 3-8 hours attracted 15 percent of males, while corpses that died within 25-30 hours increased that number to 73 percent. As more time passes, more chemical signals are released. This is not the only time scientists have observed the use of sesquiterpenes to attract the attention of insects.

As chemical signals go, this seems to be one of the most effective in manipulating these little critters. There are many possibilities for further research here, especially in effective repellents - flies can infect people with various diseases, and sesquiterpenes can be used to attract flies from a certain place, for example where food is prepared. "This is where the fungus Entomophthora muscae can be useful," said H. De Fine Licht. "It's possible that we could use the same mushroom odors as a biological pest control that would attract healthy males to the fly trap instead of the corpse."