Help! Fruit Fly / Fungus Gnat Infestation!

Thu Jul 23, 2009 3:00 am

Hello All,

I'm at the end of my rope! For almost a year now, I've been struggling terribly to get rid of fruit flies / fungus gnats. So first of all - I'm using these two flies synonymously... a local garden center expert said they were the same thing (is that accurate?)

I've tried sooo many things... About 3 different kinds of indoor insecticide, pheromone traps, balsamic vinegar traps, diluted lemon dish detergent spray...

It seems like everything I do only makes it worse, and this is becoming a real problem. I've got probably 25 plants in my apartment, and I've put a lot of time into growing them over the last 4 years or so. In other words, I really don't just want to get rid of them. Probably 50% of my plants have been chronically infested with these flies, and I've had occasional success at getting rid of them, but they always come back.

I've seen all kinds of home remedies, some of which I've tried, but I've been dogged by the feeling that maybe I'm not even dealing with the kind of fly I thought I was. But I'm pretty sure they're just fruit flies, though I can't be sure.

I'd really appreciate any help or suggestions. This is starting to become a real nightmare!

Thu Jul 23, 2009 4:05 am

This may sound weird, and I don't know that it will SOLVE your problem, if there are breeding there, but it couldn't hurt.

I vacuum mine up with my vacuum hose. Right out of the air.

Anyone looking in my kitchen when I have some must be wondering what the heck I am doing.. but it works! No squished fly guts anywhere either.

I hate fruit flies!!!!!!

I hope to hear something better than what I do!

Thu Jul 23, 2009 4:27 am

You really do need to ID them properly since they are completely different insects and have different habits. Try a Google Image search.

For Fruit Flies, see my post at the bottom of the 1st page of this thread:
http://www.helpfulgardener.com/forum/v ... hp?t=16717

For Fungus Gnats, I discussed them at length in this thread starting on 2nd page:
http://www.helpfulgardener.com/forum/v ... c&start=15

As you can see, I wouldn't think Zofiava is weird at all for vacuuming up the little flying pests. :cool:

Hope that helps. :wink:

Thu Jul 23, 2009 11:19 pm

Ha! I see that!

It's my chosen method for house flies too... I'm like the vacuum fairy!

Fri Jul 24, 2009 12:15 am

Fungus gnats are very tiny, even tinier than fruit flies and dark. They tend to stay right around the soil, not flying around in the air as much as fruit flies. If you have fungus gnats it's because you have moist soil with fungus. Part of the solution is to let the soil dry out between waterings as much as possible and treat the fungus. You can treat the flies with pyrethrin spray.

Fri Aug 28, 2009 4:53 pm

Wherever there is light and nutrients, algae will grow. Algae eat the nutrients you are trying to feed to your plants, and when pieces of algae die they attract fungus gnats. Fungus gnats lead to many other problems.

Some tips:

Keep humidity at 50% or lower
Keep heat below 75 F
Don't let stagnant water sit inside any trays
Don't mist the leaves of plants
Apply water directly to soil when it's dry
Apply a gentle insecticide in serious cases

If you're making your own compost and using it indoors, that could be your problem right there. We all know if we leave a banana peel on the counter for a few days, gnats will appear.