Hello Jim, and all.

This paper:

 "Four Common Pesticides, Their Mixtures and a Formulation Solvent in the Hive Environment Have High Oral Toxicity to Honey Bee Larvae" by
  *   Wanyi Zhu ma

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  *   Daniel R. Schmehl,


  *   Christopher A. Mullin,


  *   James L. Frazier
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...was probably largely written by the first author.  Being somewhat familiar with the procedure for writing papers in academia, I can tell you that James Frazier, whom most on this list respect, is the senior author because his name is last.  Therefore he was a "guiding light" on the research and write-up (and he probably provided the money to do the work), but the work itself was largely conducted/overseen by the first author.  In such situations the writing reflects the efforts of the first author edited by the last, while feedback and suggestions on the various drafts are requested from everyone "in the middle of the sandwich" of authors.  Those folks in the middle are the consultants, technicians, and others who were helpful but not central to the work.

The problem Jim and others are having with dosages used in this study is due to the fact that the writer was not very clear about his/her rationale.  I found it confusing, too, but I know that James Frazier is well aware of proper experimental design, and also knows better than most of us on this list what the actual concentrations of contaminants in the hives is.  So I read and re-read the paper to figure out why they are using dosages ostensibly higher than "field-relevant" ones.

Here is the most revealing text:

"Developing bees are exposed to pesticide residues by contact with the wax, beebread and contaminated bees, so the level found in trapped pollen or royal jelly is not fully representative of actual exposure of larval bees to pesticides.
For example, pollen residues of fluvalinate and coumaphos primarily originate by transfer from the contaminated comb wax, which contains much higher levels (e.g. 100-times) of these miticide residues [1]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0077547#pone.0077547-Mullin1>, [2]<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0077547#pone.0077547-Johnson1>. Therefore, in the absence of exact measures of pollen residues in larval foods, we chose to test at 10 times the levels of these four pesticides found in pollen samples."

So they used 10X residues in pollen and royal jelly because they say that wax is the major source of the poison to larvae, via diffusion.  Since the concentration of the residues is 100X in wax what it is in the royal jelly, etc. they picked 10X as a "safe hedge" concentration based on their best guess of the rate of diffusion out of the wax.

What they don't mention is that not all brood wax is equal.  Ancient crappy black brood comb is not the same as two-year old comb, and surely it has more chemical residues accrued during more years of service than one finds in new brood comb.  One would have to go to the source of their info on residues in brood comb to know whether they were using appropriately "average" values, or not.  I haven't done that.

Christina

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