On Tue, 1 Jun 2004 09:24:37 +0100 in
, "Sally"
graced the world with this thought:

Despite my using companion planting, my greenhouse tomatoes are becoming
infested with whitefly. Any recommendations of biological control would be
gratefully received.
Thanks so much

I've had luck with Safer's Soap, also, the old "cardboard painted
yellow and coated with cooking oil," works pretty well, too.