In article , Tim Tyler wrote:

Are you serious? Why on earth do you imagine that this particular
ecological association is constant over the whole earth, when no
other one is?

What didn't make sense was the idea that - because orgainisms of
one species eat organisms from another one, the two species are
not in a mutually beneficial symbiotic relationship.

I did not claim that. What I claimed was the following:

I have seen no evidence that ants either cause aphid infestations
or enhance them in the UK, and that my observations and most of
the other information I have seen indicates that it probably does
not happen, at least as far as it affects gardeners.

Note that the requirement for causing or enhancing an infestation
is a stronger one than for ants acting to defend aphids. It also
requires such a defence to make a significant difference.

Also, the CONTEXT was that of aphid infestations as they affect
gardeners. I can easily believe that there are occasional and
irrelevant exceptions, or even that there are a few, rare aphid/
ant symbioses that affect a few gardeners. I haven't seen any
evidence for the latter, but it wouldn't surprise me.

IMO, the ants are *farming* the aphids - in similar ways all over the
world.

Well, you are simply wrong. See any respectable book on entomology.
Michael Chinery "Insects", for example.

What are you claiming here? That there are differences in the ways that
ants farm aphids in different locations? Just because there are
similarities, that doesn't exculde the possibility of there also
being differences. I stand by my statement.

Would you claim that someone going out to pick elderberries is farming
the elder trees? Or that people shooting rabbits are farming them?

Just because the ants eat the aphids, that doesn't mean the aphids are
/not/ being farmed. You might just as well argue that humans are not
farming pigs because people have been observed to eat bacon.

No, it doesn't. But, as far as every reference that I have seen has
said, 'farming' ants are either absent from the UK or EXTREMELY rare,
and even ones that actively 'herd' aphids are not common.

You've presented no evidence to that effect, that I've seen.

I am pretty sure that you have responded to posts of mine where I
gave it in the past, so I think that you have forgotten. I have
posted at least the following:

I have observed black ants cohabiting with ladybird larvae on
the same aphid patch.

I have done a crude (but fairly reliable) analysis of aphid
populations on some plants (mainly broad beans) in my garden
and elsewhere, and have found evidence that the populations
were being spready by rain and adult aphids but not ants.

I have searched the net and some other places for evidence of
the claims that ants cause or enhance aphid infestations, and
found effectively damn-all.

I know that aphid infestations are a major agricultural problem,
and I knew people working on defences, but not one was even
considering attacking the ants. This indicates that they knew
it was an irrelevance.

The size of the UK makes it harder to find research on the ant-aphid
symbiosis which is demonstrably applicable.

Would you like to explain that? We have one of the largest and most
effective biological research communities in the world, an ecology
that supports God knows how many ants (but of only a few species),
and hundreds of species of aphids, many of economic importance
(thus meaning that a LOT of research has been done on them).

UK is a small country, most research on ants is performed elsewhere.

But a lot of work on aphids is, or at least was, performed here. As
I said, they are a major agricultural pest.

OK, fair enough. Try these:

UK Organic association factsheets:

``Some ants ‘farm’ aphids for the honeydew that they produce. This means
that they protect them from predators and move the pests around a plant
to new ‘pastures’. ...

``Ants have learnt to ‘farm’ these creatures, milking them for a fresh
honeydew drink. Like all good farmers, ants look after their livestock,
protecting them from predators and moving them to new feeding grounds.

The Royal Horticultural Society - on ants and aphids:

``Ants can protect aphids from attack by ladybirds and other predators in

order to secure their supply of honeydew. ...
A page about wood ants in Scotland:

... In return for the
honeydew the ants protect their precious sugar source from predators and
competing sap sucking insects.''

Look, do you understand the difference between statements and facts?

My investigations indicate that those statements are simply copying
a "well known fact", but that "fact" has little or no evidence to
support it and may well be a myth. I have so far found effectively
no EVIDENCE to support it, and my research indicates that it is very
likely false.

Can you provide any references to real evidence?

All the evidence I've seen supports the idea that ants and aphids
tend to form mutually beneficial symbiotic relationships.

I don't think that you have looked very hard, then. I know that some
ants do, and probably even some UK ants do, but I have found none
that it is a phenomenon in the UK that is significant enough to affect
gardeners.

I've witnessed phenomena which I can only explain in terms of ant
protection of aphids:

For example last year my bronze fennel was attacked in the autumn by
aphids at ground level. The strange thing was, that the aphids were all
protected by a 4cm high wall of dirt, close up against the fennel stem.
I regularly knocked this off with a stick - and it was regularly rebuilt.
The plant was about four feet from two ants nests. The only conclusion I
regard as plausible is that the ants were responsible for building the
protective wall around the aphid infestation.

Ah! Yes, I will accept that as evidence. I have never seen it, in
my garden or any other, but I have heard of it. Are you claiming
that most (or even the most common) ants will build such walls?
If so, why are they so rarely reported?

Your claim - that ants in the UK don't look after aphids - is the
one that seems to lack any supporting evidence.

I have never made that claim, as you should know. I have stated that
I believe that they RARELY do, and that such behaviour makes effectively
damn-all difference to gardeners.

If you have evidence to the contrary, please produce it.


Regards,
Nick Maclaren.