# Where do these darn "banana gnats" come from? **URL:** \ **Category:** Factual Questions\ **Created:** [September 30, 2000, 5:16am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118 "2000-09-30T05:16:58Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![stuyguy](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@stuyguy](https://boards.straightdope.com/u/stuyguy)\ **Post date:** [September 30, 2000, 5:16am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/1 "2000-09-30T05:16:58Z")
Every time I buy bananas my kitchen becomes home to six to ten flying, gnat-like bugs. (I don’t buy many other types of fruit, so I don’t know if it happens with anything besides bananas. Also, I don’t know if my bugs are what are commonly called fruit flies, so rather than misstate the situation I’m describing the symptoms rather than the disease. Onward…) These banana gnats, as I call them, seem pretty harmless and usually disappear in a few days after the bananas are gone. Here’s my Q. Where do they come from? Possibilities include: 1. They are fully developed and merely hitch a ride on the bananas when I buy them. This seems unlikely since I never notice them flying out of the bag when I unwrap my yummy yellow beauties. 2. They hatch out of eggs planted in the peel – or the fruit itself. This stikes me as a little gross, but the likely scenario, though I’ve never seen an emerging gnat-birth, nor evidence of their hatch holes. 3. They come from the outside or elsewhere and are merely attracted to the bananas. Doubtful, I think, because I live in the north and the gnats, IIRC, appear even in winter when surely they can’t survive outside. Who can solve this for me? ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [September 30, 2000, 6:51am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/2 "2000-09-30T06:51:00Z")
[Here is a somewhat related thread you may find helpful](http://boards.straightdope.com/sdmb/showthread.php?threadid=36328). ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [September 30, 2000, 11:34am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/3 "2000-09-30T11:34:06Z")
**GNATZIS!** :wally ---
**Author:** ![stuyguy](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@stuyguy](https://boards.straightdope.com/u/stuyguy)\ **Post date:** [September 30, 2000, 3:51pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/4 "2000-09-30T15:51:29Z")
wevets, thanks for the link. I must have missed that earlier thread because I thought it was about plain old flies, not “fruit flies.” But while it is very helpful regarding controlling the little buggers (pun intended), it’s pretty vague about their origins. I’d still love more insights, so keep those cards and letters coming in… ---
**Author:** ![Skelji](https://avatars.discourse-cdn.com/v4/letter/s/b38774/32.png) [@Skelji](https://boards.straightdope.com/u/Skelji)\ **Post date:** [September 30, 2000, 5:15pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/5 "2000-09-30T17:15:31Z")
stuyguy, were you cutting science class at Stuy and hanging out at Tony’s Pizza? 😃 (or did you go to the _new_ Stuy?) IIRC, Mr. Kane covered this one day (class of '81 here) Adults, larvae, or eggs will generally hitch a ride somewhere in the nooks and crannies of the banana bunch. Since they are a tropical import and are kept from any freezing temps during transport, you can find them any time of the year. Most of our common kitchen pests arrive this way. Flour weevils and meal moths often infest your food at the source of packaging, or in the store. If you’ve ever had an infestation, the source was probably something that’s been sitting in your closet for a while, giving the eggs plenty of time to hatch, feed, and if you’re lucky enough, reproduce :eek: thus ensuring that you will have ample oppurtunity for repeat performances. I have learned the hard way to take any type of flour based product and stick it in the freezer for a week, to kill any eggs. (oddly enough, those little fuckers like curry powder, too) Since we can’t do this for fruit, all we can do is dump our compost everyday (what? you don’t compost? tsk tsk), or toss our fruit by-products in the outside trash or down the chute asap. Besides, fruit flies aren’t real bad, stuyguy. As a graduate of the premier science HS, you should welcome the oppurtunity for genetic experimentation. Get yourself some mustard plants and you’re really in for a good time 😉 One wonders how many Manhattan apartment dwellers have had roaches imported from D’Agostinos. And remember, kids… Time flies like an arrow, fruit flies like bananas ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [September 30, 2000, 5:17pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/6 "2000-09-30T17:17:07Z")
I thought science had established like centuries ago that it was spontaneous generation? ---
**Author:** ![stuyguy](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@stuyguy](https://boards.straightdope.com/u/stuyguy)\ **Post date:** [September 30, 2000, 6:00pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/7 "2000-09-30T18:00:37Z")
Hey, hey, Mr. Wolf! I was wondering when another of us would show up here! Like you, I’m “Old School,” as the rappers would say – c.o. '77. BTW, I had Mrs. Chu (later Ms. Aukim, or something like that, post-divorce), not Kane, so maybe she skipped fruit flies. I guess the real reason for my curiousity is this. While I don’t consider the little guys so annoying as to go to great lengths to exterminate them (see link in wevets post), I would like to minimize their appearance. So if someone can tell me their EXACT m.o. perhaps I can devise some countermeasures. Say, for example, they hide out as fully-formed adults in the, as you say, nooks and crannies; then maybe a nice, prolonged water bath or spraying might flush/drown them out. Or if, say, they hatch out of the “hub” where all the bananas join together, maybe I can cut that off right away and discard it, leaving the bananas themselves fly-free. But if, say, the flies come in from the outside, I’m screwed because ther’s nothing I can do. So, in a way I am conducting a science experiment. And like Mr. Orna taught me regarding the scientific method, I am learning from the knowledge of researchers who went before me. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [September 30, 2000, 6:31pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/8 "2000-09-30T18:31:16Z")
I have ocassionally but not often enough to bother.Generally it is the decaying peels of any fruit that seems to make them appear and getting rid of the garbage gets rid of them. If you want more drastic and preventive measures I guess you could keep the fruit outsite (window sill?) or try washing it or spraing it with something. ---
**Author:** ![Skelji](https://avatars.discourse-cdn.com/v4/letter/s/b38774/32.png) [@Skelji](https://boards.straightdope.com/u/Skelji)\ **Post date:** [October 1, 2000, 4:49pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/9 "2000-10-01T16:49:37Z")
Hey, stuyguy…I checked on some links that I have for banana plants. (I have a lot of banana plants) According to one source, all fruit has naturally occurring yeast on the surface, which eventually ferments into alcohol as part of the decaying (or wine-making) process. This yeast is what attracts fruit flies to hang out and pick up other single fruit flies, have wild fruit fly sex, and then lay their eggs. Nothing is mentioned about preventing fruit flies, but I suppose that some kind of soapy water bath or spritz would break down the waxy coating and remove the yeast. It would probably flush out any freeloaders as well. [slight hijack] well, it _is_ your post, and since you’re a fellow Pegleg…Ever have a class with Mr. McCourt? Ever slam into a pillar in gym? Ahhh, the good old days. Stairways as narrow as coal chutes, wooden desks with inkwells and names scratched in from 1928, and no cops or metal detectors at the front door! ---
**Author:** ![stuyguy](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@stuyguy](https://boards.straightdope.com/u/stuyguy)\ **Post date:** [October 1, 2000, 11:28pm UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/10 "2000-10-01T23:28:52Z")
Wolf: Thanks for the banana tips. I’ll try the soapy bath theory. [Pegleg chat hijack reply follows] No, I didn’t have McCourt but, FWIW, I did travel in the same circles (theater & gov’t.) as Tim Robbins who was a grade older; boy, he was a nutsy kid back then. Yeah, the old building was something else – probably the only school in the world without lockers. (At least when I was there; I know they installed some years later.) I had a one hour commute each way on the subway – standing of course – lugging 25 pounds of textbooks all the while! I still walk crooked. ---
**Author:** ![Skelji](https://avatars.discourse-cdn.com/v4/letter/s/b38774/32.png) [@Skelji](https://boards.straightdope.com/u/Skelji)\ **Post date:** [October 2, 2000, 1:29am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/11 "2000-10-02T01:29:44Z")
Holy crap! I didn’t know Tim Robbins went to Stuy! Gee, that sure beats taking English with the guy from “Up The Academy”. Didn’t most of us have a one hour commute? The good old L train. I don’t miss it. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [October 2, 2000, 3:17am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/12 "2000-10-02T03:17:26Z")
Dire Wolf wrote: > [@](#): > > This yeast is what attracts fruit flies to hang out and pick up other single fruit flies… I’ve noticed that when the little buggers have been in my house, they’ve been _really_ attracted to congregate around my glass of beer. I guess it’s like a little fruit fly singles bar. ---
**Author:** ![stuyguy](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@stuyguy](https://boards.straightdope.com/u/stuyguy)\ **Post date:** [October 2, 2000, 3:41am UTC](https://boards.straightdope.com/t/where-do-these-darn-banana-gnats-come-from/35118/13 "2000-10-02T03:41:57Z")
[More Stuychat:] Dire: Yes, Tim went there. Also, Tommy Colabro, a regular on Melrose Place (or was it 90210… I dunno… I never watched either of them) was a member of my class, too. But, hey, you had Adam Horowitz of the Beastie Boys, right?