Wasps like to invade fruit flies and take over their bodies, like some insect version of Invasion of the Body Snatchers. Scientists have now discovered that fruit flies have developed a way to defend themselves: alcohol.
The Drosophila melanogaster, A.K.A. the fruit fly, has developed a resistance to alcohol. Since it thrives on yeasts that grow on rotting fruit, which can contain up to 6 percent alcohol, the flies can handle their liquor, thus preventing the fruit fly from actually becoming drunk. But the insect's tolerance to ethanol also helps protect it from predators. In a study published in Current Biology, scientists report that the alcohol kills parasitic wasps that lay eggs inside fruit flies. If the eggs survive, they grow until the fly bursts and the baby wasps eat the flies alive from the inside out.
The researchers found that parasite-infected flies actively chose more alcoholic food. The wasps didn't lay as many eggs in flies that had been partaking, and when they did lay eggs in boozy flies, the eggs didn't fare very well. They went to great lengths to prove this, according to Discover's Not Exactly Rocket Science Blog: "When Milan cut them out of the flies, he found that their internal organs were deformed, and they could barely move."
Image: Todd Schlenke