In article ,
Rodger Whitlock wrote:
On Mon, 9 Aug 2004 11:27:44 +0100, Janet Tweedy wrote:

a red oak (Quercus rubra) [is] absolutely covered
in wasps. They are attracted by the honey dew left by presumably the
aphids which are higher up the tree.

Any evidence of ants farming the aphids? Take a hard look at the
trunk and if you see ants scurrying up and down, consider that
sufficient evidence.

As Blair said to Bush.

If ants are involved, then if you can keep them out of the crown
of the tree the aphid problem should decline and fall. Some kind
of barrier around the trunk would be called for. The sticky bands
used for wintermoth control will work, but if you can get Sevin
(carbaryl) and spray a band, say, 18" wide around the trunk and
renew it every two or three weeks, that will suffice.

Nonsense.

There isn't a scrap of evidence in favour of the theory that
discouraging ants reduces aphids (in the UK), and a hell of a lot
of evidence that it doesn't usually make the slightest difference.
The ants merely follow the aphids, and are irrelevant.

If ants aren't involved, then painting the trunk with Cygon
(again, if you can still get it) might control the aphids.

Good God, why?

Almost all of the aphids in the UK spread by means of flying adults,
and then breed explosively on their target. Some other insects do
overwinter in the soil and climb up, but as far as I know no aphid
does.


Regards,
Nick Maclaren.