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Subject: Re: White flies?
From: Gary Matson <matson@awwwsome.com>
Organization: Verio Northern California's Usenet News Service
Date: Tue, 20 Apr 99 17:52:19
Message-ID: <MOD$990420.15768@rec.gardens.ecosystems>
References: <MOD$990419.23005@rec.gardens.ecosystems>



The first step is to immediately hang quite a few yellow sticky traps right
near the plants. You can make your own cheaply by buying the bright yellow
kind of plastic plates (forgot the brand, but as long as you're in the US,
they're common) (speaking of which, where do you garden? Knowing the
location makes answering questions so much easier and the answers so much
more worthwhile), and then spraying them _lightly_ with the plain kind of
Pam (no-stick cooking spray). Or you can coat them with a thin coat of
tanglefoot. You can also buy ready-made sticky traps, if you want. But
there need to be a lot of them around the plants to attract and catch as
many flies as possible early in the season.

Every early female whitefly that sticks to the traps is hundreds fewer a
couple of generations later in the year.

Next, if the weather has warmed well, (and I presume it has where you live
since you have tomatoes in the ground), then you can order lacewing eggs
from an insectary. Order lots. They are _very_ small, but the non-flying
larvae that hatch out are voracious consumers of whitefly larvae. I scatter
them all over my greenhouse each spring as soon as I start to see whitefly
on the most vulnerable plants (usually abutilon and tender salvias), and the
whitefly infestation simply never materializes.

Outdoors, the adult lacewings that emerge later will probably disperse, but
if the problem persists, you can order more eggs periodically. This may not
eliminate all whiteflies from your garden, but should reduce the numbers to
where it does not reduce your harvest or require you to wear a respirator to
hunt for the hornworms.

Abstain from insecticidal soap while using the lacewings, as it will kill
the lacewing larvae as well as whitefly larvae. You might use it once right
away while you wait for the lacewing eggs to arrive (mine come priority mail
in a day), since it has no residual and might kill a few current whitefly
larvae that would be too large for the newly hatched lacewing larvae.

The key to insect control with beneficials is to get the early stages of an
infestation. After it is a full-blown population boom, it's too late.

Good Luck!

Gary Matson Far Northern California (Sunset zone 9, barely)

Tom Stone wrote:

> I decided to try growing our garden organically this year vs.
> chemicals. I have not observed any notes about whiteflies yet. I
> noticed my first 'buddies' flitting around the tomatoes this evening.
> >From past experience with them, unless they are controlled soon, they
> will be the death of my tomatoes.
>
> In using insecticidal soaps in the past, I have not been very successful
> in controlling them since they hide under the leaves. Maybe I am
> applying the soap with the wrong type of applicator or something. I
> also thought that the sprinklers might be washing off the soap.
>
> Do you have any suggestions? I appreciate your input.
>
> Tom Stone