Fungus gnats-- was --Looking for pic of the smaller Narcissus fly
Sun, 29 Mar 2009 10:11:00 PDT
To clarify, Bacillus thuringiensis israelensis is used against Diptera 
larvae, most commonly mosquito larvae but also fungus gnat larvae.

When mixed into the irrigation water for potted plants, one must 
continue using it for at least 3 weeks to disrupt the fungus gnat's 
life cycle.

The form which kills caterpillars is different -- it's Bacillus 
thruingiensis kurstaki.

Hope this helps,
Jean in Portland, OR

-----Original Message-----
From: Kelly O'Neill <>
To: Pacific Bulb Society <>
Sent: Sat, 28 Mar 2009 8:19 pm
Subject: Re: [pbs] Fungus gnats-- was --Looking for pic of the smaller 
Narcissus fly

> Let the surface of your pots dry out to prevent
> infestation.

There are multiple advantages to letting pot tops dry out. For
the gnats though, I use a BT product (Bacillis thurgensis may
be spelled wrong). Comes in small bottles at many retail garden
stores. Takes time to build up the living anti-gnat population of
BT critters. Then they attack the larva under the soil. Works
great for me. Just dilute and pour on soil. Water it in a bit. Once
they are established, just treat new soil or pots you bring in if
you want them to be protected. The stuff probably kills all
butterfly and moth larva. I'd be careful not to get it on the leaves
of plants eaten by larva you love. May not be active outside the
soil though.
Happy "Spring" for those on the North part o' the planet, KellyO

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