Fruit Flies Tipple

Lifting the lid on the compost bucket in the kitchen produced a small cloud of tiny flying creatures.  When some landed on the counter and refrigerator I was able to get this photograph which was enough to confirm on INaturalist that it is a common fruit fly(FF) with the catchy name of Drosophila melanogaster.  If that sounds vaguely familiar, you could have come across them in basic biology courses.

FF have been the go to animal for studies about heredity and genetics since Thomas Hunt Morgan began using them at Columbia University in 1910.  They are undoubtedly the most studied insect and their sex life has been an open subject of discussion for a hundred years.  

FF are ideal for genetic and other research.  Measuring 2mm, they are easily contained in large numbers.  Their lifecycle is10 days at room temperature and the female lays up to 2,000 eggs.  They are easily anesthetized to study genetic changes in morphology.  Their reproductive rate isn't appreciated as much in our kitchen.

The female deposits feces on the eggs so the larvae can acquire the enzymes needed to digest bacteria on rotting fruit as well as the sugars.  Adults can use fruits, yeasts and insect carcasses as their food sources.  They are also attracted to the fermenting sugars present in spilled alcoholic beverages.

D. melanogaster male- Wikimedia

Now studies have demonstrated the effects of their alcohol intake.  Male fruit flies that have been rejected by females drink significantly more alcohol than those that have mated freely, suggesting that alcohol stimulates the flies' brains as a "reward" in a similar way to sexual conquest.

 Many people get flushed when they consume alcohol, and so do fruit flies but in a different and beneficial way.  Fruit flies feeding on fruit that is fermenting obtain protection from tiny parasitic wasps.  Not only were the wasps less likely to lay eggs on imbibing FF but the eggs are less likely to survive.  

"If you dissect open a fly that was fed alcohol food, the wasps were obviously dead and in a lot of cases the internal organs in the wasp larvae had fallen out the wasp's anus," Schlenke said. "They were turned inside out." Now that's a bad hangover."  LiveScience

FF on a banana - Wikipedia

A detailed Wikipedia page can answer questions I haven't even thought of.  A final connection you may have encountered in English class as an example of a pun or double entendre, "Time flies like an arrow; fruit flies like a banana."  It even has its own page in Wikipedia.  Those fruit flies sure get around!