Re :  The paper Williams, et al (2015)  Neonicotinoid pesticides severely
affect honey bee queens.

Perhaps I should start by saying that the the subject line (4 ppb
thiamethoxam and 1 ppb clothiandin = double the drone layers) is
misleading, apparently due to a misinterpretation of the study's findings
by the originator of this thread.  There was no mention in the study of
queens becoming drone layers.

I've now had the chance to discuss the paper at length with the author, of
whom I think highly (and with whom I previously coauthored a paper).  We've
discussed the shortcomings in the original design of the experiment, which
come back to haunt us when we try to interpret the results.

In this study, queens were reared in two different cell builders, the Test
group being fed neonic-spiked pollen.  This added the variable of the two
groups of queens being reared not only with different exposure to neonics,
but also by different colonies.  This may or may not have had an effect.
But in a better-designed experiment, replicate cell builders would have
been used to eliminate the effect of "colony."

The main finding of the study was that after four weeks of being in mini
mating nucs stocked with roughly 1000 workers, fewer queens were
successfully laying in the Test group that had been fed neonics during the
cell building period.  The question then, is why?

Since nurse bees typically produce jelly free of pesticide residues, and
since the researchers did not test the jelly in the queen cells, we have no
way of knowing whether the developing queens were even exposed to neonics.
Without such confirmation of exposure, one cannot say that the queens were
actually exposed to the treatment.  The bees that *were* exposed were the
nurses that reared the queen larvae and later used to stock the nucs.

Interpretation of the results is confounded by the lack of replication of
cell builder colonies as mentioned above.  But more importantly, there was
another more serious error in design.

The 1000 workers with which nuc was stocked, instead of being taken from a
homogenized group of control bees, were instead taken from either the
spiked or control cell builder colonies.  So the nucs now had two
additional variables other than the potential exposure of the queen larvae
to neonics:

1. The bees used to stock the nucs in each experimental group came from one
of two different colonies, and
2.  The bees used to stock the Test nucs came from colonies that had been
fed neonics for 36 days, ensuring that those workers had been reared under
continuous neonic exposure, and then when they emerged had likely consumed
neonic-spiked pollen for their entire nursing period up 'til when they were
transferred to the mating nucs.

What this means is that the Test mating nucs were founded with a handful of
broodnest bees that had been exposed to neonics continuously for their
entire lives.  Any direct apparent effects on the Test queens, which,by the
way, flew and mated exactly the same as the Control queens and had
significantly more ovarioles than the Control queens  (but may have had
somewhat fewer stored spermatozoa), is pure conjecture.

The question then is, were the apparent differences between queen
performance due to direct effects of exposure to the queens during their
larval development, or were they do to the performance of the workers in
the nucs?  (This would be of interest in its own right).

Could the apparent differences in the number and viability of the
spermatozoa be due to poor queen care by those 1000 treated workers, or due
to poor thermoregulation, or simply due to their premature death leading to
rapid dwindling of those 1000 bees in the nucs?  The experiment was not
designed to answer those questions.

 The unfortunate result is that no conclusions can be legitimately drawn
regarding any direct effect on the queens, and the title of the paper is is
misleading (and inappropriately worded for sensationalism).   However, this
experiment certainly raises some questions, and I hope that it will be
replicated without the design flaws in order to answer the researchers'
original question of whether "exposure to field-realistic concentrations of
neonicotinoid pesticides would significantly reduce honey bee queen
performance."

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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