> As those around the world read the Mark Winston
> article I will take his
> article a step further .
I am not as connected in the well-kown scientific
communty as you are, just few comments from a small
hobbyist beekeeper (in my clumsy groping English).
> The problem as I see it is in proving Imidacloprid
> is the root of the
> problem.
I am not sure to understand this root concept. I was
under the feeling pesticides intoxication is one more
trouble bees have to face. One more, perhaps one too
much for numerous colonies in an already
low-biodiversity environment (namely the colony has to
face intensiv and short nectar and pollen flows
alternatively with starving period), already facing
pests and treatments.
If Imidacloprid *is* the problem then we
> are moving into an area
> bees being effected by 1ppb and less.
In september 2003, a special French commitee released
its final report about Risk assessment for bees due to
Imidaclopride exposure
(http://www.agriculture.gouv.fr/spip/IMG/pdf/rapportfin.pdf
). The first part of this 106 pages study is a
complete review and validation of existing studies in
the world about imida toxicity tests on bees. The
second part is an assessment study with risk
calculations via each source (nectar, pollen, etc.)
from each major imida treated plant (corn, etc.).
Calculations are based on results from validated
studies. Imida by-products in plants were also
considered when data were available, as far as I
understood. Some by-products (olefine) are more toxic
for bess than imida itself.
And as the
> French & some U.S.
> beekeepers problems show seriously effected.
The French were the first to react at a national level
and to pressure politics. But there are claims about
imida poisoned bees and debates in other Western
Europe countries (Belgium, Germany, Netherlands,
Switzerland, etc.). This geographic spread of the
problem has to be taken into account when explaining
hives losses and similar symptoms in all those
countries. Yet, each area have its own planted
patterns using Imidacloprid (Sunflower in France,
potatoes in North America for example, so the problem
may be more or less intense depending on imadaclopride
use, surfaces planted and their particular
consequences on bees exposure).
> Through new methods we can now detect even smaller
> amounts than ppb.
>
> Researchers are puzzled that the 1ppb of
> imidacloprid detected in nectar &
> pollen could be the root of the problem. After all
> ppb of known higher toxic
> chemicals have been found and the bees *seemed*
> unaffected.
But I think bio-essays (i.e. proboscis extension
response) to evaluate sublethal effects (that can lead
to medium term disorder in the colony, or weakness
that will make wintering a hazardous venture) are very
recent (Pham-Delègue, 2002). It seems those bio-essays
are not specific enough to be a tool in large field
(Pham-Delègue and al, 2002; Tautz and al, 2003). They
still have not been use on large scale, if I
understood well; they are also time consuming and will
certainly not be conducted easely by an "average
beekeeper". My point is bees "seemed" unaffected
perhaps because we had not the tools to see it. And
even if they "seemed" unaffected in laboratory
conditions for a short period of time, they can be
affected in the field in production conditions and
submitted to real other stress factors, IMHO.
Scientists try to segregate cause and conditions to
satisfy repetitivty criteria; good for the scientific
method but bees are exposed to multiple pesticides.
Synergetic toxicity can not be taken into account by
such approach, without talking about by-products. Does
it mean beekeepers have to wait for the science
miracle in lab to prove, without any doubt, bees are
dying from one pesticide more than from another one ?
Or that bees could have passed through the winter if
not exposed but exposure was too much for half of them
?
> "What is the problem if the problem is *not* being
> caused by imidacloprid"
I have trouble with that question. It tends to
attribute one cause to one consquence. The scheme may
be more complicated.
> Because the evidence I have seen does not represent
> a "smoking gun" by the
> past history of toxic problems most including myself
> & Mark are saying
> simply :
>
> "Are we correct is saying that imidacloprid is the
> only problem and give up
> looking for a possible other answer.
Ask the question that way also carries the answere. It
seems to me no one can resume all trouble to one
cause. I would propose other ways to considere the
question :
"Does imida implies a significant risk for bees and
for beekeeping industry ?"
And if its use generate more benefits for the society
than potential drawbacks for a community, "does imida
use internalize all costs ?"; namely who pays its
use's consequences ?.
Thus, the fact it is the only problem or the root
problem is no more the question. The question becomes
Is its use acceptable ?
> All of the older beekeepers clearly remember the
> malady named in all the bee
> books "disappearing disease".
Several studies showed some pesticides generate a
disappearing syndrom at the hive (Bendahou and al,
1999 for cypermethrin; Vandame and al, 1995 for
deltamethrin) so that suspecting imida does or other
pesticides does not look un-reasonnable.
> The French problem resembles the old "disappearing
> disease".
It sounds more like a widespread problem than a nation
limited problem. I do not know if they right or no,
but their point about imida is a lot more than a
feeling.
Good D-day commemorations,
Hervé
Laval, Canada
Pham-Delègue and al, Behavioural methods to assess the
effects of pesticides on honey bees, Apidologie 33
(2002) 425-432
Tautz and al, Behavioural performance in adult honey
bees is influenced by the temperature experienced
during their pupal development, PNAS 100 (2003)
7343-7347
And I am too lazy for the 2 last references but they
are listed in the first reference
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