In nk.net Snooze
wrote:
We've got some whiteflies as well here in San Jose. They seem to like
the tomato and zucchini plants, far more then they like the roses.
I agree - they can really hit a tomato bush but I've never seen these
things take to roses.


Spray pesticide doesn't work very well, because they tend to hide on
the underside of the leafs.
That depends on the spray. A systemic one will enter the plant and
poison the sap, making the insects drink their own death. You CAN use
those sprays on food crops although I'd personally rather not do that.
On roses, systemic is the way to go.