Two new studies:

http://m.phys.org/news/2013-03-pesticide-combination-affects-bees-ability.ht
ml



About the first study:
Cholinergic pesticides cause mushroom body neuronal inactivation in
honeybees
Mary J. Palmer1, Christopher Moffat1, Nastja Saranzewa1, Jenni Harvey1,
Geraldine A. Wright2
& Christopher N. Connolly1

Abstract
Pesticides that target cholinergic neurotransmission are highly effective,
but their use has
been implicated in insect pollinator population decline. Honeybees are
exposed to two widely
used classes of cholinergic pesticide: neonicotinoids (nicotinic receptor
agonists) and organophosphate
miticides (acetylcholinesterase inhibitors). Although sublethal levels of
neonicotinoids
are known to disrupt honeybee learning and behaviour, the neurophysiological
basis
of these effects has not been shown. Here, using recordings from mushroom
body Kenyon
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. Our findings demonstrate a neuronal
mechanism that
may account for the cognitive impairments caused by neonicotinoids, and
predict that
exposure to multiple pesticides that target cholinergic signalling will
cause enhanced toxicity
to pollinators.

I read both, Randy :-)

Kind regards,


Ghislain De Roeck,
Belgium.

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