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help with fruit flies/fungus gnats in compost

Posted by nancybeetoo wOR USDAz8 (My Page) on
Wed, Dec 10, 08 at 22:38

Does anybody have ideas on dealing with excessive fly populations? They fly up in my face when I am working with the compost? In my eyes, ears, mouth etc. Super annoying. In the summer I had house flies and dealt with them by using two bins at once and alternated covering the piles with plastic sheeting. Since these piles typically heat at 140 F I was able to cook the larvae and diminish populations that way.

I look forward to seeing what ideas come out of this group. I have been reading with interest over the last year. I love the dedication and creativity that I have seen.

Nancy in western Oregon, about to get some real winter weather after a dry and mild fall.


Follow-Up Postings:

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RE: help with fruit flies/fungus gnats in compost

Cooking them out is the preferred way. Leaving them alone is a good way, after all they are decomposing something. Burying your fruit deeper is a good way, too.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Wed, Dec 10, 08 at 23:24

I had this problem this past summer with my Earth Machine. I didn't have leaves yet and I didn't have enough carbon/brown/whatever you want to call it to throw on top of the kitchen waste. Once the leaves started falling and I could get that mixed in the fruit flies/gnats went away.

Val


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RE: help with fruit flies/fungus gnats in compost

Fruit seems to be the worst offender, really drawing flies. I also had a big crop of maggots when I used really "rich" green and wet neighbor's grass clippings (fertilized grass). What I do is try to bury the fruit or other kitchen waste, turn it face down like watermelon rind, and keep shredded paper handy to throw over it.


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RE: help with fruit flies/fungus gnats in compost

Since those wee buggers need a pretty moist environment to hatch and grow the presence of them is an indication that your compost is too wet. Add dryer material, dry leaves, dry soil, or a dessicant to control them.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Thu, Dec 11, 08 at 8:14

kimm - I must disagree with you. In my Earth Machine there was no water added and the compost was not wet. It was merely the uncovered kitchen waste (fruit and vegetable peelings) that were attracting the "wee buggers". Once I was able to cover the offending kitchen waste they went away.

Val


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RE: help with fruit flies/fungus gnats in compost

Our main compost pile is a distance from the house, so we have an old, lidded, 13 gal. waste can on the back porch that accumulates the smaller bits and pieces - the sort of compostables that you might hold in the palm of your hand and ponder "Is this worth getting on the mud boots and hoofing it all the way down to the compost?" and decide "no". So, over the course of a few weeks, it builds up.

I opened this up the other day, and out flew a swarm of fruit flies that blackened the sky. It was like those cheesy horror movies where you just know something bad is going to happen next. The dog ran in terror, whimpering. There were so many fruit flies that it immediately brought back those fond memories.....

When I studied Genetics, oh so many years ago, one semester we were supposed to do a multi-generational study on the inheritability of albinism in fruit flies. This didn't work out too good, and there were a lot, a whole lot, of fruit flies flying around the biology building for a few weeks there.

So I waited until it was below freezing and went and dumped the thing.


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RE: help with fruit flies/fungus gnats in compost

A thick cover of dry browns tends to keep the flying gnats to a minimum in my pile. (Note that I said minimum... not eliminate.)


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RE: help with fruit flies/fungus gnats in compost

The eggs that Fungus Gnats, Fruit Flies, and most other flies lay need a fairly warm and moist environment to hatch and then the maggots the develop need a fairly moist environment to grow. Without that fairly moist environment they will not hatch and grow. Therefore logic follows that if your have these in your compost then your compost is fairly moist, most likely too moist to properly compost since these wee buggers are hatching and developing on the surface which when wet enough to allow that to happen indicates the interior of the compost is way too wet.


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RE: help with fruit flies/fungus gnats in compost

Yes but Kimmsr, Nancy is in a USDA zone 8 and one could logically surmise that even if she left out a piece of fruit on her deck that the fruit flies would find it quite attractive and pester the area. In essence, you don't even need a compost in such a zone/warm area to attract the little buggers. She could have the driest compost with moist fermenting fruit in it and they would just think she had supplied them with a nice friendly home.

Geez, when I think about it, they gang up on my kitchen if I leave a lonely banana on the counter. Nasty things!

So no, the compost is not necessarily too wet. It simply has a food source and very romantic conditions for fruit flies.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Sat, Dec 13, 08 at 15:01

Kimm - you don't play well with others...do you? How can you keep insisting that the compost is too wet when I'm telling you it wasn't?

If you read very slowly maybe you'll see that it was the exposed fruit/vegetables that was causing my problems with the fruit flies/gnats. Once covered with a layer of leaves, they went away.

Almost everyone here (but you) is saying basically the same thing to the original poster, bury or cover the fruit. You really have no idea whether the compost is too wet or not, you just like saying that, don't you? C'mon, you can admit it.

Val


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RE: help with fruit flies/fungus gnats in compost

  • Posted by jean001 z8aPortland, OR (My Page) on
    Sat, Dec 13, 08 at 16:03

Val,

You wrote: "In my Earth Machine there was no water added and the compost was not wet. It was merely the uncovered kitchen waste "

As it turns out, those conditions and components do make for wet compost -- not necessarily sloppy wet, but wet enough for such flies to propagate freely.

And as has been said, even if it's just a solitary piece of fruit on the surface of a pile, it's a prime food source for those particular buggers. It's one of those things that, if you build it, they will come.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Sat, Dec 13, 08 at 19:03

Hi Jean - I appreciate your comment and agree with what youre saying.

In my case however, although I didnt want to go into the whole story because I didnt think it was a big deal, I will. It was early fall (this year) and Id emptied the EM of its contents and was just starting a new one. I threw in the last of my shredded paper, no water. Shredded paper wasnt even an inch and I knew I needed to make some more but the leaves were getting ready to fall so I didn't think much about it. The next day we decided to make applesauce and wound up with a lot of peelings. I didnt even think about it when I sent the kid out to dump the "kitchen waste" in the EM. The kid didnt spread them around, just dumped them into kind of a pyramid shape. Ooops! No leaves, no paper. I didnt have a need to go out there for a few days but when I didwoohoo - fruit flies and gnats out the patudynaturally.

Now the paper (what little there was) was still dry. And it wasn't for another couple of days that I was able to gather enough leaves to cover said "kitchen waste" and the bugs went away. Then Kimmsr writes the compost is too wet..well, there wasnt any compost in there to be wet. That is why I disagreed with her. She then writes back again that it has to be the compost is too wet. So that is why I wrote what I did.

Kimmsr is wrong about the fruit fly/gnat problem that I had although she may well be right about someone elses problem.

Val


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RE: help with fruit flies/fungus gnats in compost

  • Posted by pt03 3 Southern Manitoba (My Page) on
    Sat, Dec 13, 08 at 20:13

Okay...

What the heck is a "PATUDY"?

Lloyd


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Sat, Dec 13, 08 at 20:28

I could say that I'm too much of a lady to tell you but that would just be wrong....but so that I don't offend I'll give you a link. Scroll down just a tad and the picture should tell all.

I should say that I am in no way related to the link I just found it funny.

It's a word that's been used in my family for a long time.

Val

Here is a link that might be useful: Nudy Patudy


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RE: help with fruit flies/fungus gnats in compost

"Kimmsr is wrong about the fruit fly/gnat problem that I had although she may well be right about someone elses problem."

He, by the way, :-). And no I am not wrong. Logic. :-)


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Sun, Dec 14, 08 at 8:29

He, by the way

My bad

And no I am not wrong

Your bad

I will agree that we must disagree.

Val


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RE: help with fruit flies/fungus gnats in compost

Magma displacement.

Here is a link that might be useful: reference.


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RE: help with fruit flies/fungus gnats in compost

An entymologist friend asked me this, "Why on earth would someone want to encourage what are considered garden pests to take up residence in the compost from where they would be spread to the rest of the garden?" when we were talking about this subject.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Mon, Dec 15, 08 at 7:24

A psychologist friend asked me, "Why would someone keep saying the same thing over and over when they know it makes them appear silly?" when we were talking about this subject.

Maybe you meant entomologist and I don't see where anyone is encouraging fruit flies/gnats in the compost. Everyone is talking about how to get rid of them.

Val


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RE: help with fruit flies/fungus gnats in compost

The OP seems to have more than one type of fly problem. She mentions house flies, which are not attracted by fruit and ARE a hygiene problem if left to breed. However, most of this discussion has been about fruit flies, which are more likely to be the type which 'flies up in clouds' and is small enough to be breathed in. Something which nobody has addressed so far is whether or not the OP should actually be worrying about fruit flies. She says they are 'super annoying' which, if they are in large numbers is true. However, they don't bite or sting, don't spread disease and are not a pest of healthy fruit. They don't paddle about in rotting flesh or faeces like house flies. They only go for damaged, decaying or very ripe fruit. They will not 'spread to the rest of the garden' unless there is a food source to go to. The best way to deal with them is just to deny access to ripe/damaged fruit, whether by covering the fruit bowl in the kitchen or burying any fruit put on the compost heap. In our house their favourite summer hang out is a glass of red wine. We are always fishing them out. Annoying - yes. Dangerous -no.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Mon, Dec 15, 08 at 8:49

Here's a link to a fact sheet about fruit flies. It's interesting to note that it does mention "moist" organic material once but that there are many many other ways to attract fruit flies.

I also find it interesting that they use the term "moist" and not "wet" as in "your compost should be moist not wet".

Here is a link that might be useful: Michael F. Potter, Extension Entomologist


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RE: help with fruit flies/fungus gnats in compost

Val said,
I don't see where anyone is encouraging fruit flies/gnats in the compost. Everyone is talking about how to get rid of them.

It's time for me to stand up and be counted. In my original reply to the OP I was very luke warm in my suggestions for getting rid of the flies. I even suggested leaving them alone. In my own pile I encourage the flies. When I put out banana and orange peels, I lay them carefully on top of the pile until the fruit flies find them. Next time I visit the pile, I bury them. I consider flies and everything they bring with them to be important to the biology of the pile.


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RE: help with fruit flies/fungus gnats in compost

As the people that have written articles about composting at North Dakota, North Carolina, Cornell, and a couple of other research institutions have stated the presence of flies and their larva in compost is a sign of poor management. They contribute nothing of any value to the compost. Compost, to digest properly, should be about as wet as a well wrung out sponge, not really moist and certainly not moist enough to support the growth of flie maggots, whether fruit flies, fungus gnats, of other flies, and repeating this is not a sign of insanity.
So, Why on earth would you encourage an insect that is considered a pest elsewhere to live and grow in your compost?


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RE: help with fruit flies/fungus gnats in compost

Kimmsr your point has been made. You don't need to repeat it. People can read it - once is pleasing, twice is more then plenty, three times is bothersome, anything more than that is down right rude.

BTW there is more than one way to "manage" a compost pile. A low maintenance, cool, rarely-turned, pile is not necessarily improperly managed. The advantages of a low maintenance pile is that the labor input is minimal. The disadvantage of a low maintenance pile is that it takes longer to get finished compost. A cool pile relies on larger organisms than bacteria for primary decomposition. These insects are not necessarily garden pests.

However this thread is about fruit flies, which pretty much everyone agrees are pesky. No one on this thread is encouraging fruit flies. Everyone on this thread has offered suggestions on how to get rid of fruit flies. The OP can read all of the advice and choose which she would like to try.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Tue, Dec 16, 08 at 8:19

Ahhh...dchall, I see now. Kimmsr must have been referring to you when he wrote:

An entymologist [sic] friend asked me this, "Why on earth would someone want to encourage what are considered garden pests to take up residence in the compost from where they would be spread to the rest of the garden?" when we were talking about this subject.

Since he doesn't preface his posts regarding to whom he is speaking, I sometimes get confused. Also, I mostly agree with you about the fruit flies in the pile. I don't stress over them too much, hence my post that I waited until the leaves fell before covering them up. If I had been too worried about them, I would have run in and shredded more junk mail :-)

I have to say I don't like when they fly up from the EM into my face though. Ugh!

Val


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RE: help with fruit flies/fungus gnats in compost

  • Posted by pt03 3 Southern Manitoba (My Page) on
    Tue, Dec 16, 08 at 9:05

-humor- I have no more friends left since I took up composting.

-serious- Sometimes (if I haven't tumbled in a few days and there is fresher materials in them) there are fruit flies/bugs of some kind in the tumblers (only in summer, go figure) but I usually tumble a few times before I add so they get mixed in and are not an issue. Once the material decomposes a bit they don't seem to be around as much.

Lloyd


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edited

  • Posted by pt03 3 Southern Manitoba (My Page) on
    Tue, Dec 16, 08 at 9:22

The original was actually this:

"-humor- I have no more friends left since I took up composting. (by the way it took about three months in a hot pile)"

but took out the last part in case it might offend some.

Lloyd


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RE: help with fruit flies/fungus gnats in compost

  • Posted by ajpa z6 (My Page) on
    Tue, Dec 16, 08 at 11:07

Catch and throw a (live) spider into the pile?

I'm just kidding -- I know nothing about composting but I grew up in the tropics and I hate flies of any kind. Good luck!


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Tue, Dec 16, 08 at 16:32

Lloyd - Are you for real?

Not the part about composting your friends...that part I believe.

It's the fact that you didn't post (by the way it took about three months in a hot pile) the first time but then turned around and posted the words right after that. Frankly, I'm offended!

Val - who plagiarizes other people and who's going to....(well, you know where)

PS - to keep it on topic. You CAN get fruit flies in your house on mushy fruit. Yes, it's damp, mushy and wet but my compost wasn't :-)


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RE: help with fruit flies/fungus gnats in compost

Ha! I didn't get Lloyd's joke on composting friends until Val spelled it out. Duh.

Believe it or not - and Lloyd, don't go getting apoplectic - but even though I disagree with Kimm, I think he has as much right to repeat his stance as the rest of the people have to continue to argue with it.

Now, that being said, might I suggest something? When dealing with someone that puts out bs to sound smart one should try using the bs-ers own tactics and go one step further. He slings names. Sling them back. I picked only one. Cornell. The difference is that I don't expect you to trust me. Instead I encourage you to read what they have to say about fruit flies in compost (sorry, but I keep forgetting how to put a link in a post):

http://www.css.cornell.edu/compost/faq.html#What about

Funny. It doesn't say at all that they shouldn't be in compost. In fact, it doesn't even say the problem has to do with moisture. The fix doesn't even include removing moisture or adding dry material. Why? Because logic that leads to fruit flies equal too much moisture is not logic at all. A basic knowledge of fruit flies will dispel that anyway. And I'm not saying all should have that basic knowledge because I only just learned a bit about them when I started vermicomposting.

Fruit flies are not borers. They can't dig down into the compost to lay eggs (as Cornell indicates, oddly enough). They need air. Yes they need moisture. Just like the bacteria that are responsible for composting. But mostly they need fermenting foods. If you want to trap them, use a homemade vinegar trap. There are instructions in the Cornell document I referenced or you can just google it. They are cheap and simple. You might find yourself making one for your kitchen like we did, but beware of curious cats. The results of these traps are so good that you may even begin to believe fruit flies are naturally suicidal.

Joepyeweed, what do you mean by magma displacement? You said that after I ranted about Kimm and his misinformation in another thread and I thought you were criticizing my rant against Kimm and people that purposely misinform to sound as if they are an ultimate authority on a subject.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Tue, Dec 16, 08 at 17:53

Joe...Joe....Joe - since we had a small misunderstanding I'm gonna help you out.

See the rectangle message box where you type your message? Right below that is a long rectangle box that says "Optional Link URL:" - paste your link in that box instead of in your message body.

Right below that is a rectangle box that says "Name of the Link:" - In here is where you type what you want to call the link (example would be Cornell)

Using those two rectangles is how people make the link show up at the bottom of their post.

If you look at JoePyeWeeds post there is a link at the bottom of it that says "reference". This link will take you to a message thread that explains her use of "Magma displacement". It's actually very funny.

See, I can be helpful sometimes instead of a smart patudy :-)

Val


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RE: help with fruit flies/fungus gnats in compost

  • Posted by pt03 3 Southern Manitoba (My Page) on
    Tue, Dec 16, 08 at 19:34

I can't believe people don't get my humor. (well actually I can but I needed to type something in this area to post the link for Joe).

Lloyd

Here is a link that might be useful: Cornell (for Joe)


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RE: help with fruit flies/fungus gnats in compost

Hi,

This is Nancy Bee, the OP (Original Poster), writing in with an update and summary.

First- the update on the cooking. I covered one bin with plastic, then a layer of straw for insulation, then more plastic to hold the heat in, for a couple days. When I removed the plastic a few adults flew out but not many. I had placed a thermometer at the top of the compost just below the plastic and temperatures were over 130 F so I think the cooking of larvae and pupae was successful. Since then we have had several days of below freezing conditions and the adults are gone. I have also been adding more straw to try to cover the exposed food. It's difficult because so many people are contributing to the compost. Even if I go by twice a day to cover with straw there is still exposed food for some period of time.

More background: I manage composting for a community of about 70 people. We generate about 2 cubic yards of compost a month. It is particularly rich in food scraps and does tend to be quite moist. In December in Oregon, almost everything going in is pretty moist. I do add straw as the only dry ingredient. The bins heat very well- typically at 130 to 140 and even up to 155 F. So, I do not think that they are too wet to be aerobic.

Reading this discussion has made me wish that I had had the flies identified. Without knowing what they are, we are only speculating about the life cycle, speed of reproduction etc.

What we know is that it appears that they are successfully completing their life cycle in the compost. Next fall I expect that they will reappear and then I will get them identified.

Thank you for all your thoughts and good wishes.
Nancy


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RE: help with fruit flies/fungus gnats in compost

Hi folks - enjoyed the repartee (banter/jousting/wordplay), but must say that there were probably more words about yourselves, than on topic. tsk, tsk.
Lloyd, your levity was much appreciated by this reader.
Hang in there, Val...

Nancy Bee, the plastic is somewhat effective by itself, heating the top pile surface (where flies breed) due to direct sunlight on it, thereby reducing their penchant for reproduction (a method I use).

However, below is a method that has worked for me for a long time, to AVOID such 'invasion' issues during hot/moist south Texas coastal summers:
I very rarely have any insect larval/adult propagation problem in my compost because I make sure that my pile has sufficient BT in it. It occurs naturally in soil and when sufficiently present, is a very effective microbial insecticide.

The Cornell link referenced below states "...fly larve..." without listing specific fly larvae susceptibility, but from my experience, this has been 'an ounce of prevention' that has (apparently) worked well for me over the years (based on the issues I deal with, helping a multitude of other composters in our 3-county area).

Yeah prevention - like 'snapping' my fingers to keep elephants away.
Don't see any, do ya?

I produce compost for wholesale distribution, and cannot afford (time or money) to deal with such issues, since my professional reputation is at stake.

BT is supplied to all residents of this County free, from our Health Department in clay 'donuts' (for mosquito control), which I keep soaking in my screen-covered, water-filled kitchen-scrap bucket, then cast the water (with other soaked, rotting material) on a near-to-top layer of my pile. Once - then BT is in the material through harvest, and in leached 'tea' inocculant as well. Can also be purchased from most plant nurseries. One donut lasts for 15-20 buckets at the rate I use them.
Then I cover the pile top surface with 10-mil black plastic.

This procedure is SOP since I also 'cap' my freshly-made piles with manure to 'seal' them - and as you know, even 'aged' manure attracts a multitude of flying critters.

Like taking vitamins to help keep your immune system strong. Do vitamins work? Prevention Magazine says a person will live longer by taking vitamins. So my compost piles get BT - for a strong immune system. BT works for me.

Pile heat is not very effective, since the surface area where fruit (and other flies) breed, does not get (and stay) sufficiently hot on an uncovered pile.

Robert

Here is a link that might be useful: Bacillus thuringiensis


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RE: help with fruit flies/fungus gnats in compost

Thanks Val and Lloyd.

I'm soooo embarrassed that I didn't see that bold print right below the message box all this time. For some reason I thought you had to do the href stuff on this site. I have successfully shown my incredibly absent minded side twice in one thread.

Nancy, that's awesome. 70 people! That's a lot of kitchen scraps. If you didn't feel like reading my longwindedness, at least take a look at the link I mentioned that Lloyd provided. I picked that one because it actually answered your original question of how to deal with these flies with near immediate results. Well, that and I'm partial to Cornell.


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RE: help with fruit flies/fungus gnats in compost

but must say that there were probably more words about yourselves, than on topic.

Of course, because I am the center of my universe. It is all about me after all. ;-)


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RE: help with fruit flies/fungus gnats in compost

soil guy, I use Bt for fungus gnats all the time in my greenhouse and house plants - the same deal with soaking a 'skeeter doughnut in water and then using the water to irrigate the plants.

Good to know it works in compost as well.


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RE: help with fruit flies/fungus gnats in compost

That is a clever idea for using BT in the pile. Still I would rather give the flies a shot at doing that thing they do so well. My pile is out on the ground with nothing to contain it -- it is a pile. I never cover it so 300 days a year it is pretty dry.

Another interesting thing I found when using the mosquito dunks (a variety of BT) is that the 20-year accumulation of black mold covering the bottom of my bird bath completely disappeared in about 6 months. "Suddenly" it was concrete colored again. I could even see the air bubble holes from the concrete pour. I'm not sure that killing mold is a good thing but it is what I saw happen.


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RE: help with fruit flies/fungus gnats in compost

dchall, The BT is a good thing in your bird bath. The birds will appreciate the cleanliness - just as you do. Watch for more birds in the bath as a result.

Because of ground contact, your pile should already have sufficent BT from the natural soil, but do recommend that you water it. Dry conditions make BT go 'dormant' (i.e., the 'donut' your received was dry).

A way to tell, is if you don't see any beetle larvae (grubs) in the BOTTOM of your compost (shovel INTO the bottom of the pile at grade, about 2' - no grubs? Good.
If you find grubs, there is not enough BT. Add more BT and water more. Beetle larvae are not particularly 'bad' in compost, but they do not contribute much either - and are an effective means of "measuring" BT effectiveness.

And really, the fly larva don't do anything good for your compost - they only proliferate in the top layer and do cause damage to your neighbor's fruit and vegetables,
particularly the Mediterranean fruit fly (Medfly), Mexican fruit fly and Oriental fruit fly. But the USDA does not consider them to be a major threat to the U.S. agriculture due to effective erradication programs in place.

However, each composter should do his/her part...for the good of all.

Robert

Here is a link that might be useful: Fruit Fly damage protection - CA


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RE: help with fruit flies/fungus gnats in compost

Not all strains of the Bacillus thuringiensis bacteria are equally effective for all types of insects. You need to get the type most effective for the pest you have. So BTI is what is in those mosquito dunks while BTK is what is prrayed on plant leaves to control the leaf eaters, and BTSD is used to control the Colorado Potatoe Beetle. There is no BT out there to control grubs. For them you need to spread Bacilus popilliea, Milky Spore Disease.
There is no evidence that putting any of this in your compost is effective.


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RE: help with fruit flies/fungus gnats in compost

So soilguys experience with using Bt is not evidence?

But I wouldn't use Bt in my compost, because I am gardening for wildlife. I am a native plant gardener and I plant to attract butterflies, moths and caterpillars to my garden.

Insects are food the birds. So I am not gardening to eliminate or minimize insects, in fact I am gardening to maximize insect populations. (Which is why my veggie garden is at my FIL's house)

I would worry that Bt in my compost would be harmful to the caterpillars in my garden.

The key is a balance of many insects keeps any one insect from dominating and doing damage.


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RE: help with fruit flies/fungus gnats in compost

kimmsr,

Disagree with you, simply based on experience.
I used to have lots of grubs in my very moist compost before using BT.
Rarely see a grub of any kind anymore, using the same methods/materials with the addition of BT.
http://www.nysaes.cornell.edu/ent/biocontrol/pathogens/bacteria.html
States: Primary hosts: caterpillars; some BEETLE and fly larvae.
Also states: "Over 90 species of naturally occurring, insect-specific (entomopathogenic) bacteria have been isolated from insects, plants, and the soil, but only a few have been studied intensively".
So I give credit to BT.
I put some good soil in my new compost piles, which has had applications of all commercial BT strains, so I can't say which one (if any) are at work against grubs. Doesn't matter to me. So I give credit to BT, et al. - and don't have names for the other 86 or so insect-specific (entomopathogenic) bacteria spoken of, OR other such non-specific bacteria that may not have been identified yet.

http://ohioline.osu.edu/hyg-fact/2000/2500.html :
'Grubs' is a 'generic' term, used for larvae of a large group of beetles called SCARABS. The most important species are: Japanese beetle, Popillia japonica Newman; May or June beetles, Phyllophaga spp.; northern and southern masked chafers, Cyclocephala spp.; and black turfgrass ataenius, Ataenius spretulus (Haldeman). Other, more localized, white grub pests are: European chafer, Rhizotrogus majalis (Razoumowsky); the Asiatic garden beetle, Maladera castanea (Arrow); and the green June beetle, Cotinis nitida (Linnaeus).

Option 4: Biological Control - Milky Diseases - Several strains of the bacterium, Bacillus popilliae (bacterium is extracted from Japanese beetle grubs and is most active against this species), have been found that attack white grubs...Unfortunately, recent studies in Kentucky and Ohio indicate that the currently available products have NOT PERFORMED WELL IN OUR SOILS. (caps are mine).
Goes on to say that parasitic nematodes are a up to 80% effective, but "...do not appear to be effective from one season to the next".

So you can take exception with me if you want to - your opinion is just as valid as mine - but now let's hear from YOU about your EXPERIENCE with grubs...

Robert


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RE: help with fruit flies/fungus gnats in compost

Like most other people I have grubs, and have found tons of them in some loads of horse manure. However since grubs do very little damage I see no reason to spend time, money, and energy on control, birds do a good job (especially the Starlings). Some people will argue that grubs need to be controlled because moles eat them, but moles also eat earthworms so just eliminating the grubs will not solve the mole problem, and killing off the earthworms is not a viable option. So while there is a whole industry (very profitable, too) based on eliminating moles the simple fact that it will be an immpossible task does not seem to enter into anyones equation.
There is no strain of Bacillus thuringiensis that is effective for controlling grubs.


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RE: help with fruit flies/fungus gnats in compost

  • Posted by val_s z5 central IL (My Page) on
    Sun, Dec 21, 08 at 9:45

At our last house, the grubs were making yellow patches in the lawn. There we brought in a lawn service to control them. Whatever they used worked.

Here, after tilling a spot for the garden, I did notice there were a lot of grubs in the spot I tilled. I didn't think too much about it because I just thought the birds would get them. Then a mole moved in to that area within a week. A friend told me to put down something called milky spore and it would eventually kill the grubs thus moving the mole out. She also said that the reason birds didn't get more grubs is because they can't stand the light and as soon as they were exposed they burrowed down deeper.

Not sure if it (milky spore) will work but I was desperate because I wanted to get my garlic in before winter. Didn't happen because even though I managed to kill one mole, within a few days another moved in. Someone said that a mole can hear you tilling your garden from a mile away.

Hate grubs, hate moles!

Val


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RE: help with fruit flies/fungus gnats in compost

Must admit that mine is a particular problem:
Some of my finished compost goes to people who buy it.
That's why I took steps to eliminate grubs in it.
Because the people who buy it don't finding like grubs in it.
Why?
They don't like them in their garden, eating plant roots, or under their grass killing their lawn.

If I have grubs in my compost, which is thereafter added to a garden or spread on a lawn,
Then to the extend grub eggs/larvae are alive in the compost, to that degree a garden has just been inocculated with grubs.
Better to not have them in compost in the first place.

kimmsr,
Do you just not comprehend what I wrote to you?
Or do you just like to aggravate folks and 'stir the pot'?
I said, I can't prove it does (even though Cornell said it might) but I no longer find live grubs in my compost.

I CHALLENGE you to PROVE the last statement you made - via a scientific BT resource, or state that your words are ONLY your opinion - OR just be quiet.

Robert


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RE: help with fruit flies/fungus gnats in compost

This summer we had a while when the fruit flies/gnats or whatever they are were aggravating. One needed to hold one's breathe when flinging compost in the pile, so as to avoid breathing the little buggers in. I compost massive quantities of fruit and veg, market leftovers. I add a lot of dried leaves and sometimes shredded branches, but still, fruit is wet. Unless one is going to dehydrate fruit going into the pile, it really can't help being moist. Fruit is moist. Doesn't mean I neglect my pile, thank you. It means I am putting massive quantities of fruit and veg in, and it will naturally take a little time for the moisture to come out of them, regardless of how many leaves are added.

Marcia, normally a kimmsr fan


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