> . Honeybees are
> exposed to two widely
> used classes of cholinergic pesticide: neonicotinoids (nicotinic receptor
> agonists) and organophosphate
> miticides (acetylcholinesterase inhibitors).
>

This is a revealing study. If you step back from it and look not at the
neonics and their effect, but at the whole picture you can get a very
different take.

One issue of mine in the studies of the neonics is that there is no
comparison with prior pesticides. For example, why not have, in any study
of the effect of neonics on bees, organophosphates or pyrethroids for
comparison/controls? This study shows an additive effect of the neonics and
organophosphates. Also, that they are both cholinergic pesticides and have
the same effect on bees.

Which brings up another question. We beekeepers lived with organophosphates
for decades. They were not just in agriculture, they were in backyard
gardens and on our pets. They were all over but our bees seemed to survive
in spite of them.

We had tracheal mites and 80% kills but there was no finger pointing toward
the organophosphates with their effects on bees.

Then we had the serendipitous arrival of Varroa, neonics, new virus, nosema
cerana and the capstone, CCD. The organophosphates were still around (and
still are in your hive if you use Cumophose).

What got the blame for bee deaths? What still is the number one culprit and
has some beekeepers suing the EPA?

Again, from the study-

cells in acutely isolated honeybee brain, we show that the neonicotinoids
> imidacloprid and
> clothianidin, and the organophosphate miticide coumaphos oxon, cause a
> depolarizationblock
> of neuronal firing and inhibit nicotinic responses. These effects are
> observed at
> concentrations that are encountered by foraging honeybees and within the
> hive, and are
> additive with combined application.
>

This study implies that a prior pesticide potentially caused bees problems
at low doses, just the same as the neonics. If I were in the insecticide
business, I would run comparative studies to see if we are looking at
something brand new or if it has been with us for decades but we just did
not notice.

As I said, it is a revealing study.

Bill Truesdell
Bath, Maine

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