The old saying goes “you can catch more flies with honey than with vinegar.”
But fruit flies love the chemistry of rotting fruit -- and that includes vinegar.
So can we hack fruit flies’ sense of smell to get rid of the darn things?
It’s worth a try.
First of all: you’ll probably catch some flies with honey.
That’s because honey is mostly sugar, and fruit flies get most of their energy from
sugar.
But they detect sugar mainly by taste.
NOT smell.
So setting out a bowl of honey, which doesn’t smell all that strong, is not the most efficient
way to make the flies come... flying.
Fruit flies feed on, y’know, fruit.
And fruit contains all sorts of chemicals, including volatile ones -- meaning the ones
that can easily vaporize and lift off into the air, thereby activating a fly’s sense
of smell and telling it hey!
Tasty fruit here!
One of those volatile chemicals is the acetic acid found in vinegar.
Acetic acid tends to be released by microbes, specifically yeast, living on rotting fruit.
And research has shown that fruit flies are extremely good at detecting vinegar -- it
leads them to food -- usually rotting fruit, which is both a delicious meal and a place
to lay eggs or mingle with other single fruit flies.
But flies are actually picky when it comes to how intense the vinegar smell is.
When they’re not super hungry, they’ll actually ignore fruit with either too much
or too little vinegar.
Instead, flies will zero in on a Goldilocks zone of not too rotten, not too fresh -- just
ripe.
But when they are hungry, a switch flips in their tiny, poppy seed-sized brains and they’ll
go for any vinegar they can smell: too much, too little, doesn’t matter, they’ll eat
it -- although that need to lay eggs and mate plays in to it too.
So there’s our first piece of advice for catching fruit flies: Take out the trash and
lock away your bananas in an airtight container.
In other words, starve your flies.
If there’s no other food around, they are more likely to try and eat from your vinegar-based
trap.
But fruit flies can smell more than just vinegar.
In fact, their senses get pretty specific.
They can sniff out volatile compounds like these, which are indicative that a specific
type of yeast have set up shop on the fruit.
You might have heard that beer or wine, which are yeast-fermented beverages, attract fruit
flies.
And actual fly biologists will say the same -- fruit flies will come to a trap baited
with wine or beer.
That could be because these same yeasty compounds are sometimes found in beer or wine.
But flies will also come for apple cider vinegar, which is also made using yeasts and also probably
cheaper.
Is that apple cider vinegar better than plain old white vinegar, or some other kind?
Maybe -- apple cider vinegar is made from apple juice, and fermented by yeast in much
the same way hard cider, beer, and wine are -- except in vinegar, there are also these
bacteria hanging out.
So it’s possible that the yeast are making the same “come and get it” chemicals in
cider vinegar.
Plus, cider vinegar is made from fruit, and still contains some of the same volatile chemicals,
like these.
So apple cider vinegar probably still smells like fruit to a fruit fly.
So here’s what to do: Put a splash of cider vinegar in a jar and place a funnel inside,
then tape the funnel in place.
Or just rubber band some plastic wrap over the top and poke a few holes.
Either way, make sure you remove all the more fruit-fly-delicious sources of food, or they’ll
just keep munching on that avocado you swear you’re gonna get to.
JUST MAKE GUACAMOLE ALREADY!
What are you waiting for?
PBS Digital Studios just launched a new show, and I've got to say it is the best idea for
a show ever.
Head over to the Storycast YouTube channel to check out Tacos of Texas, a new series
that will explore the Lone Star state's most iconic tacos.
Join longtime friends and taco journalists Mando and Jared as they explore the stories,
food traditions, and communities that led to each city's unique take on tacos.
Just don't watch on an empty stomach.
Seriously you will get hungry.
Thanks for watching.
What's your tried-and-true technique for getting rid of fruit flies?
Let us know down in the comments what works for you.
Feel free to experiment.
We're gonna be honest.
We could have set up an experiment ourselves but none of us wanted to volunteer to set
a bunch of flies loose in our kitchen or the video studio.
Make sure to subscribe and hit the bell for notifications and we'll see you next week.