Found alive in home-made wine. What is it?
April 10, 2010
Hello. At a party in October 2009 some friends brought home-made wine. Someone noticed something floating – and moving – in their glass. Removed one, and took photographs using macro setting on my camera. It was tiny, maybe 3 millimeters in length? A fair amount of wine was consumed before noticing the swimmers, and it would be nice to know what they were. The wine was made in “classic” fashion – without a lot of regard for health and safety concerns. (Obviously!) It was made in Summer/Fall 2009, in an earthenware jug with a cheesecloth “stopper”. (I know, I know…) I did not drink any of the wine, but my friends did. So what did they actually consume? I hope you can help!
New Brunswick, Canada

Vinegar Fly Maggot

Hi Lincoln,
We believe this is the larva of a Vinegar Fly in the family Drosophilidae, a group also called Pomace Flies.  They are commonly called Fruit Flies, though that name is more correctly reserved for members of another family of flies that are agricultural pests.  The Fruit Fly of genetics experiments is actually a Vinegar Fly, Drosophila melanogaster.  The larvae develop in fermenting fruit, including spirits like beer and wine.  Vinegar Flies are often found in restaurants and bars where they are attracted to the open bottles, and finding dead flies in the bottles can become a health code violation.  Though the thought of fly larvae in the wine may not be appetizing, no harm would come from accidental consumption.  BugGuide does not have any images of the larvae of Vinegar Flies, but we did find a nice sketch of the life cycle of Drosophila on the Biology Department of Kenyon College website.

Mr. Marlos,
Thank you most kindly for your response!
I will pass along your information to the people who *did* drink the wine…along with a stern lecture on cleanliness and safety!
Thank you also for correcting a long-held misconception on my part. I had always thought that “Drosophila” and “Fruit Fly” were synonymous. I shall now know them as Vinegar Flies! And I will do my best not to ingest any of them…if at all possible!
I am replying via e-mail and not via a comment at the website, as I am not a member, and therefore I could not log in.
But I definitely wanted to pass along my appreciation.
(On the subject of the website, whenever I click on the link to my posting:
I just get a blank page. I am not sure if this is a serious problem, but I thought you should know.)
Please take care.
Thank you for your interesting and informative website!
Lincoln (from Canada) –

One Response to Vinegar Fly Maggot: What's That Bug in my Wine???

  1. CarolC says:

    Will fruit fly larvae ruin my wine already in carboys? Will racking soon and adding sulfite help?

Leave a Reply

Your email address will not be published.