Male fruit flies drink more alcohol to get females to like them

Fruit flies (Drosophila melanogaster) are tremendously fond of fermented foodstuffs. Technically, it's the yeast they crave, produced by yummy rotting fruit, but they can consume quite a lot of ethanol as a result of that fruity diet. Yes, fruit flies have ultra-fast metabolisms, the better to burn off the booze, but they can still get falling-down drunk—so much so, that randy inebriated male fruit flies have been known to court other males by mistake and fail to mate successfully.

Then again, apparently adding alcohol to their food increases the production of sex pheromones in male fruit flies, according to a new paper published in the journal Science Advances. That, in turn, makes them more attractive to the females of the species.

"We show a direct and positive effect of alcohol consumption on the mating success of male flies," said co-author Ian Keesey of the University of Nebraska, Lincoln. "The effect is caused by the fact that alcohol, especially methanol, increases the production of sex pheromones. This in turn makes alcoholic males more attractive to females and ensures a higher mating success rate, whereas the success of drunken male humans with females is likely to be questionable."

Fruit flies are the workhorses of modern genetics research, used to study everything from cancer to sleep disorders. They make excellent model systems because they share so many genes with humans, plus they are cheap, easy to breed, and can be genetically altered easily. Many years ago, I had the privilege of visiting the University of California, San Francisco laboratory of behavior geneticist Ulrike Heberlein, who spent years getting fruit flies drunk in an "Inebriometer" to learn about the various genes that influence alcohol tolerance. (Heberlein is now scientific program director and laboratory head at the Howard Hughes Medical Institute's Janelia Farm Research Campus.)