"Marie Dodge" writes:
Actually it says: "Flour preparations Flour mixed in water *is said to be*
very effective against aphids and spider mites.." I'm curious, said by who?

You might be interested in an aphid spray I use. 1 part denatured alcohol +
3 parts water. Spray onto the pests. They cease moving immediately, and more
importantly, never move again. I have not found it to harm any plants, but
there is nothing stopping you hosing it off 10 mins after applying if you
wish, as by then it has done its job. As always, it would be wise to do a
test spraying on just one plant initially, and then on the others 2 or 3
days later. I've found it ideal for killing aphids clustered on the tender
new tips of plants such as roses and lemons.

Denatured alcohol is called "methylated spirits" here in Australia. It's
just ethyl alcohol with a trace amount of an evil-tasting stuff to stop
people drinking it and evading the alcohol tax. (You could use cheap vodka
in place of the alcohol I suppose!!)

You could try it on spider mite. I have used it on small grubs, but doubt
that it would kill whitefly.

We live out in the country so that's impossible. We're surrounded by
woodland and underbrush, weeds and wildflowers. It would take thousands of
dollars and aerial spraying would be required. But thanks for the info.....

I read that aphids can over-winter on thistles. Skeptical, next winter I
took a closer look. They sure do: the leaves were thick with aphids. Then
I found one milk thistle with no aphids on its leaves. I pulled it up and
found its roots clad in an overcoat with aphids! So one measure you could
take is to make sure there are no milk thistles in fallow parts of your
garden.
--
John Savage (my news address is not valid for email)