In article ,
Stephen Howard wrote:
On 1 Jul 2003 19:22:17 GMT, (Nick Maclaren) wrote:

In article ,
Ron wrote:
Well. the flypaper is still catching blackfly and the war against the ants
continues but at least the aphids are very few on my runner beans - got to
leave some for the ladybirds! Talking of runner beans, I'll be picking
the first ten or twelve tomorrow.

Do you have a scrap of evidence that persecuting the ants has any
effect on the blackfly?

It should do. Ants 'farm' sap-sucking insects for the 'honeydew' they
excrete, and in return they offer protection against predators.
Reduce the 'minders' and you should tip the odds in favour of the
beasties that would normally prey on the black/green fly.

That is an old wive's tale.

The 'farming' ants are all tropical, and the common ants in the UK
do not even 'herd'. I have made some reasonably scientific observations
on blackfly, in my garden and elsewhere, and the evidence was that the
presence of ants makes no difference whatsoever. My observations have
been confirmed by entymologists.

Far more ants in the UK prey on aphids than protect them in any way,
and (after several years of querying in many ways), I have failed to
discover ANY evidence that ANY ants EVER increase aphid damage in
the UK. As I mention above, quite the contrary, in fact.


Regards,
Nick Maclaren.