Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:

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 certainly don't remember this - and visiting Google groups didn't
seem to help.

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.

Others say:

``Management of ants is a key component of aphid management [...]''

- http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7404.html

....and...

``Using covers such as horticultural fleece can give good protection
against aphids and the viruses they transmit. Some ants "farm" aphids
for their honeydew that they produce. This means that they move the
pests around a plant to new pastures". If a tree is badly infested with
ants and aphids, a band of fruit tree grease, or a purchased 'grease
band' painted round the trunk stops the ants climbing up the tree.''

- http://www.myerscough.ac.uk/arboricu...b%20p age.pdf

....and...

``Apply grease bands or barrier glue to stakes and trunks. Keep in place
until late April. Can be reapplied in early summer to control ants,
which encourage aphids.''

- http://www.crown-nursery.co.uk/organictips.html

The percieved relationship is widespread enough to appear in
UK Organic association factsheets and in advice given by the
Royal Horticultural Society - I think it's quite reasonable
to think gardeners with aphid problems often look to their ants.

Also, it's a common sales pitch for ant killer sellers to point out
that ants protect and cultivate aphids.

I think you may be under-estimating the attention which
gardeners with aphid problems give to ants.

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?

I have no reason to think the ants in my garden (Bristol) are particularly
special.

I also found this description of similar ant behaviour:

``This genus of ants is known to tend aphids by “milking” them for
honeydew and therefore will attack the natural enemies of aphids.
Oftentimes they will take chewed up plant fibers and build a shed or
wall around the aphids to protect them from natural enemies and from
rain.''

- http://www.butterflies.org/news.cfm?newsID=10

I can make no claim about how widespread this behaviour is -
since I've only seen a few reports of it.

I've not seen ants attacking other plants with aphids in this way -
I conjecture that fennel is unusual in the extent to which it places
a carbohydrate rich food store at an accessible location at ground level.

Both my fennel and my ants survived the winter. I'll try to photograph
the behaviour - if it occurs again later this year.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:
Nick Maclaren wrote or quoted:

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.

I'd best restore the snipped exchange in full in this case:

--BEGIN--
Even there, I doubt that "ants are the aphids' friends", because it
is probably that there is more ant predation on aphids than ant
protection of them. [...]

AFAICS, that doesn't seem to make sense :-(

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

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.

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.
--END QUOTE--

To reiterate my original point, observations of ants eating aphids
should not count as evidence that they are not also cultivating them, and
are not also in a mutually beneficial symbiotic relationship with them.

Analogously, evidence of humans eating bacon does not count as
evidence against the hypothesis that humans farm pigs; and that
the two species are in a mutually beneficial symbiotic relationship.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

In article , Tim Tyler wrote:

Also, it's a common sales pitch for ant killer sellers to point out
that ants protect and cultivate aphids.

I think you may be under-estimating the attention which
gardeners with aphid problems give to ants.

No, I am not. I am stating that it is based on prejudice.

There is considerable evidence that ants milk aphids of honeydew,
at least in the UK, but effectively damn-all that they cause or
enhance aphid infestations. There are two possible explanations
of the observed interactions, plus intermediate states.

A) Ants herd aphids, move them to new locations, protect them
from predators. As a result, they both cause new infestations and
enhance their severity.

B) The aphids produce honeydew as a way of "buying off" ants
(Danegeld, in human terms), ants are a parasite on aphid populations
and aphids would do better if they were absent.

As far as I know (and I have looked fairly thoroughly), there is no
good information to distinguish the two in the UK. In some cases of
tropical ants, the former is pretty clear; it is also the case that
some species of root aphid are dependent on Lasius flavus, but I
don't know if any are serious pests in gardens. But, as far as the
aphids that are major pests in the UK are concerned, forget it.

It would be possible to test this, say, for Lasius niger and Aphis
fabae (a VERY common combination and claimed symbiosis). Make a
21'x21' concrete slab with 6" walls, put 100 3' by 1' diameter tubes
on it, fill them with gravel and soil, put 3" of water and a film
of paraffin on the slab, a broad bean plant in each tube, string to
connect each black square (assuming a chequerboard) and ensure that
there were Lasius niger nests around.

Then measure the Aphis fabae infestation of each plant and the crop
of beans, and analyse them. My prediction is that there would be
damn-all difference. Yours is that the ant-accessible plants would
do worse.

What I am saying is that, until such an experiment (or equivalent)
has been done, there is damn-all evidence that ants either cause or
enhance aphid infestations in the UK. There is some weak evidence
supporting it (the research you mentioned and your earth walls), and
some weak evidence opposing it (mine on distributions and relative
crops), but both are too indirect to be definitive.


Regards,
Nick Maclaren.

Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:

Also, it's a common sales pitch for ant killer sellers to point out
that ants protect and cultivate aphids.

I think you may be under-estimating the attention which
gardeners with aphid problems give to ants.

No, I am not. I am stating that it is based on prejudice.

I was referring to this claim:

``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.''

Maybe the people you consulted didn't pay attention to the ants -
but I reckon there are quite a few others who do. After all,
the UK Organic association and the The Royal Horticultural
Society, publicly state that ants protect aphid infestations -
and IMO, their relationship mythical or not, is pretty common
knowledge.

There is considerable evidence that ants milk aphids of honeydew,
at least in the UK, but effectively damn-all that they cause or
enhance aphid infestations. [...]

It would be possible to test this, say, for Lasius niger and Aphis
fabae (a VERY common combination and claimed symbiosis). Make a
21'x21' concrete slab with 6" walls, put 100 3' by 1' diameter tubes
on it, fill them with gravel and soil, put 3" of water and a film
of paraffin on the slab, a broad bean plant in each tube, string to
connect each black square (assuming a chequerboard) and ensure that
there were Lasius niger nests around.

Then measure the Aphis fabae infestation of each plant and the crop
of beans, and analyse them. My prediction is that there would be
damn-all difference. Yours is that the ant-accessible plants would
do worse.

The equivalent - with a tarred cloth around a tree - might be simpler
still.

There are some drawbacks to this kind of experiment - since there
is at least one cofounding factor: the ants may protect the aphids
against other creeping aphid predators, which would also have their
access to the plants inhibited by any such physical barrier.

I'm not sure "the establishment" is likely to perform such an
experiment - since the symbiosis between ants and aphids is
common knowledge, and not exactly newsworthy.

However, this *is* the sort of experiment those wanting to
vindicate the ants might like to consider.

What I am saying is that, until such an experiment (or equivalent)
has been done, there is damn-all evidence that ants either cause or
enhance aphid infestations in the UK. There is some weak evidence
supporting it (the research you mentioned and your earth walls), and
some weak evidence opposing it (mine on distributions and relative
crops), but both are too indirect to be definitive.

It would be nice to see an analysis of the type in:

``Friend or foe? A behavioral and stable isotopic investigation of an
ant-plant symbiosis.''

- http://calorierestriction.org/pmid/n=15179580

....for a range of UK plants.

However, I'd be pretty suprised if a fairly major link between ants and
aphids was not established in the process. Ants get a good fraction of
their diet from honeydew - and IMO, the question is a *lot* like asking
what would happen to the number of cows in the UK if the humans were
removed.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

In article , Tim Tyler wrote:

Maybe the people you consulted didn't pay attention to the ants -
but I reckon there are quite a few others who do. After all,
the UK Organic association and the The Royal Horticultural
Society, publicly state that ants protect aphid infestations -
and IMO, their relationship mythical or not, is pretty common
knowledge.

I find the idea that repetition of a myth by Eminent Bodies will
turn it into a fact somewhat bizarre. If they have no evidence for
their beliefs, those are prejudice. If they do, I can't find it,
and you haven't.

Then measure the Aphis fabae infestation of each plant and the crop
of beans, and analyse them. My prediction is that there would be
damn-all difference. Yours is that the ant-accessible plants would
do worse.

The equivalent - with a tarred cloth around a tree - might be simpler
still.

But it would be vastly less reliable. No matter - not even THAT
has been done.

However, this *is* the sort of experiment those wanting to
vindicate the ants might like to consider.

Guilty until proven innocent? How very scientific.

However, I'd be pretty suprised if a fairly major link between ants and
aphids was not established in the process. Ants get a good fraction of
their diet from honeydew - and IMO, the question is a *lot* like asking
what would happen to the number of cows in the UK if the humans were
removed.

Nobody is denying the link. What I am saying, and I need to repeat
for the Nth time, is that I have reason to believe that there is no
evidence that ants cause or enhance aphid infestations in the UK,
in an agricultural or horticultural context at least.

If you find any reasonable evidence for that, please post. But
please don't bother to post yet more examples of self-proclaimed
experts parrotting each others prejudices.


Regards,
Nick Maclaren.

Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:

Maybe the people you consulted didn't pay attention to the ants -
but I reckon there are quite a few others who do. After all,
the UK Organic association and the The Royal Horticultural
Society, publicly state that ants protect aphid infestations -
and IMO, their relationship mythical or not, is pretty common
knowledge.

I find the idea that repetition of a myth by Eminent Bodies will
turn it into a fact somewhat bizarre.

It /is/ an odd idea. Where did you get it from?

However, this *is* the sort of experiment those wanting to
vindicate the ants might like to consider.

Guilty until proven innocent? How very scientific.

Ants have been proven gulity on numerous occasions. The issue
appears to be that few (though at least one) of the experiments
which I can find illustrating ants protecting and cultivating
aphids were done with UK-native ants and aphids.

I see no terribly convincing reason for thinking that these will
prove to be an exception.

These are some more UK papers which look like they bear on the
subject. Though reviewing them is currently beyond my scope,
some answers may lie within:

El-Ziady, S., and J. S. Kennedy. 1956. Beneficial effects of
the common garden ant, Lasius niger L., on the black bean
aphid, Aphis fabae Scopoli. Proceedings of the Royal
Entomological Society London (A) 31:61–65.

Nixon, G. E. J. 1951. The association of ants with aphids
and coccids. Commonwealth Institute of Entomology, London UK.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

In article , Tim Tyler wrote:
Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:

Maybe the people you consulted didn't pay attention to the ants -
but I reckon there are quite a few others who do. After all,
the UK Organic association and the The Royal Horticultural
Society, publicly state that ants protect aphid infestations -
and IMO, their relationship mythical or not, is pretty common
knowledge.

I find the idea that repetition of a myth by Eminent Bodies will
turn it into a fact somewhat bizarre.

It /is/ an odd idea. Where did you get it from?

Your responses to my pointing out that certain things were not
evidence.

You might be amazed at how much common knowledge (even as known by
'experts') is incorrect, and you certainly would at how much is
actually just favoured speculation.

Ants have been proven gulity on numerous occasions. The issue
appears to be that few (though at least one) of the experiments
which I can find illustrating ants protecting and cultivating
aphids were done with UK-native ants and aphids.

Actually, no. In the vast majority of cases, they were assumed
to be guilty and the results were shown to be consistent with that
hypothesis. There is a major difference.

These are some more UK papers which look like they bear on the
subject. Though reviewing them is currently beyond my scope,
some answers may lie within:

El-Ziady, S., and J. S. Kennedy. 1956. Beneficial effects of
the common garden ant, Lasius niger L., on the black bean
aphid, Aphis fabae Scopoli. Proceedings of the Royal
Entomological Society London (A) 31:61–65.

Now, THAT is evidence. It is the first proper test of anything
that I have heard of. It did an experiment very like the one I
described (oil bath and all), though with a very small sample
(3+3 for the matched sample, 7+7 in toto). If we ignore the statistical
uncertainty that causes, they showed that ants are consistently and
significantly associated with much larger numbers of aphids, and a
delay in developing their winged forms. The ant-free samples had
vastly more winged adults. They provided evidence to show that
the ants did remove ladybird larvae but that this was probably not
the main reason for the larger numbers of aphids.

They did NOT show any difference in the bean crop, nor did they
even speculate as to how many winged adults had developed on the
ant-free plants and left. It is therefore very weak evidence that
ants cause larger aphid infestations, rather than just preserving
the aphids in the apterygous form.

Nixon, G. E. J. 1951. The association of ants with aphids
and coccids. Commonwealth Institute of Entomology, London UK.

That isn't in the UL, so I can't check it. But, for the Nth time,
NOBODY BUT NOBODY is denying the association, so why do you keep
bringing it up?

The relevant questions are whether ants CAUSE aphid infestations
or ENHANCE their severity. The first paper is weak evidence for
the latter, and I have STILL seen no evidence of the former!


Regards,
Nick Maclaren.

Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:
Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:

Maybe the people you consulted didn't pay attention to the ants -
but I reckon there are quite a few others who do. After all,
the UK Organic association and the The Royal Horticultural
Society, publicly state that ants protect aphid infestations -
and IMO, their relationship mythical or not, is pretty common
knowledge.

I find the idea that repetition of a myth by Eminent Bodies will
turn it into a fact somewhat bizarre.

It /is/ an odd idea. Where did you get it from?

Your responses to my pointing out that certain things were not
evidence.

Notice that in the case cited above, the claim in quesition was whether
your are under-estimating the attention which gardeners with aphid
problems give to ants.

I think the advice of expert UK gardening bodies on the subject
(correct or not) is relevant to that issue.

Also in this area, do not ignore the power of advertising:

``Horticultural glues are very effective organic controls to prevent
crawling insects reaching the tops of trees in order to feed, mate, or
deposit eggs. This includes codling moth, procession caterpillars, tent
caterpillars and ants. Controlling ants reduces scale, aphids and mealy
bug problems, as the ants protect these pests.''

- http://www.greenharvest.com.au/pestc...glue_prod.html

``Ants protect ants from predators to take advantage of the sugary sap. An
effective barrier to ants leaves aphids vulnerable to natural
predators.''

- http://www.paradisepark.co.uk/acatalog/Other_Pests.html

These are some more UK papers which look like they bear on the
subject. Though reviewing them is currently beyond my scope,
some answers may lie within:

El-Ziady, S., and J. S. Kennedy. 1956. Beneficial effects of
the common garden ant, Lasius niger L., on the black bean
aphid, Aphis fabae Scopoli. Proceedings of the Royal
Entomological Society London (A) 31:61?65.

[...]

Nixon, G. E. J. 1951. The association of ants with aphids
and coccids. Commonwealth Institute of Entomology, London UK.

That isn't in the UL, so I can't check it. But, for the Nth time,
NOBODY BUT NOBODY is denying the association, so why do you keep
bringing it up?

As I said, I was trying to find relevant research on ants and
aphids published in the UK. I was pleased to hear my first
paper contained relevant information. This one doesn't have
such a relevant-sounding title - but I obtained it from a
bibliography dealing with ant-aphid mutualism - and it *may*
contain relevant information.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

In article , Tim Tyler wrote:

Notice that in the case cited above, the claim in quesition was whether
your are under-estimating the attention which gardeners with aphid
problems give to ants.

No, you introduced that irrelevance into a serious debate about
whether ants cause or enhance aphid infestations.

I am fully aware that the hoi polloi believe an excessive amount of
claptrap, and that remark applies equally to the hoi polloi in
science. You are clearly underestimating the number of people who
believe that the cure of aphids is dianetics, prayer and chanting,
or wearing only linen on Fridays.

I don't give a damn what the great unwashed believe - I am talking
about what really goes on. You may side with the great unwashed if
you wish.


Regards,
Nick Maclaren.

Nick Maclaren wrote or quoted:
In article , Tim Tyler wrote:

Notice that in the case cited above, the claim in quesition was whether
your are under-estimating the attention which gardeners with aphid
problems give to ants.

No, you introduced that irrelevance into a serious debate about
whether ants cause or enhance aphid infestations.

The subject of whether gardners paid attention to ants was raised
by you, with:

``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.''

Lots of gardners with aphid problems *do* pay attention to ants -
as I've mentioned - since the idea that ants protect aphids is
a commonplace one - and is supported by expert UK gardening bodies
in their factsheets.

Perhaps the subset you contacted represent a biased sample.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

In article , Tim Tyler wrote:

Notice that in the case cited above, the claim in quesition was whether
your are under-estimating the attention which gardeners with aphid
problems give to ants.

No, you introduced that irrelevance into a serious debate about
whether ants cause or enhance aphid infestations.

The subject of whether gardners paid attention to ants was raised
by you, with:

``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.''

I was talking about scientists researching into aphid control, not
about the ecologically ignorant hoi polloi.

Perhaps the subset you contacted represent a biased sample.

Unquestionably. They were real scientists. Totally unrepresentative
of the general population.


Regards,
Nick Maclaren.

An anecdote:

Today I found four large black aphids on the very top of a metre high
passion flower plant which I had moved into the garden - from my nursery -
a few days previously.

I photographed the plant - and have indicated the aphid location with
a red arrow:

http://timtyler.freeshell.org/temp/a...ion_flower.jpg

The rest of the plant was entirely free of aphids - though there
were other similar-looking aphids on the nasturtium in the foreground.

The four aphids were being attended by two ants. I removed the
insects from the plant with my fingers.

My theory about how the aphids arrived at that spot is that the aphids
were carried a metre up into the air by ants - and placed on the plant's
most tender growth area by them.

Possibly this act was performed by the same two ants I found in
attendance.

If this theory is correct it may be possible to observe the transportation
act in progress - with a bit of luck. I'll keep an eye out for this
event. It seems it may be possible to catch the ants in action.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.

Tim Tyler wrote or quoted:

http://timtyler.freeshell.org/temp/a...ion_flower.jpg

[...]

My theory about how the aphids arrived at that spot is that the aphids
were carried a metre up into the air by ants - and placed on the plant's
most tender growth area by them.

Possibly this act was performed by the same two ants I found in
attendance.

If this theory is correct it may be possible to observe the transportation
act in progress - with a bit of luck. I'll keep an eye out for this
event. It seems it may be possible to catch the ants in action.

The event seems too infrequent for me to stand much chance of observing
it :-(

I did some aphid speed tests, though - and was impressed with the
speeds the aphids could manage when stressed - the aphids I saw could
easily have reached the top of the plant under their own steam.

Another possibly-ant-implicated phenomenon I've observed is "leaf-tents"
at the tops of currant bushes. These do not look like a simple side
effect of aphid attack - and look *exactly* as though they are "designed"
to provide UV protection - and heat shade - for the aphids underneath.

I presume these are mainly created by attacking the backs of the leaves,
causing them to curl - and aphids are significantly better placed to
perform such attacks than the attending ants are. However, the leaf
tents appear to have a significant degree of sophistication - and I
suspect that the ants may have had a guiding hand in their creation.

A literature search might help identify whether such a phenomenon has
ever been linked to the presence of ants.
--
__________
|im |yler http://timtyler.org/ Remove lock to reply.