" My question is did they do their science correctly? "

In this study larva were grafted and fed artificially, not fed by worker bees.  They compared diets that contained the surfactant at 10ppm plus viruses versus the same diet without surfactant and viruses.  They say 10 ppm of surfactant in the diet is 1/1000 the spray concentration typically used.

Did they do the experimental properly so the results can be trusted?  I would say yes from what is in the paper.  But, I also have concerns and questions.

1.  Is there any data to show that in field conditions the bees actually bring the surfactant back to the hive?  I see no such disclosure.

2.  If the bees do bring surfactant back to the hive what concentration is it in pollen and nectar?  Pure gut feeling is it would be well under 10 ppm by the time it was in larval feed unless by some mechanism it happens to get concentrated into the feed.  That really is a very high concentration for something sprayed at a rate of a few tenths of a pound per acre.  Think about spray for a minute.  Much of the spray ends up on leaves, branches or the ground.  Only a small % actually hits the flowers or buds.  Of that % that hits flowers only a small amount would end up in pollen or nectar.

3.  Part of the surfactant in pollen or nectar is going to get lost on the bee gathering the pollen or nectar and part could be lost by absorption into wax.  So again, getting 1/1000 of the total sprayed into larval feed seems high to me.

4.  They ran one concentration of surfactant in the larval feed.  It would be interesting to see a dose response holding virus titer constant with various surfactant concentrations in the feed.  Would 1 ppm in the feed be as bad as 10 ppm?  Perhaps it would be.  There is no way to know without doing the experiment.

5.  It is curious they only saw a positive response with black cell queen viruses and other viruses did not show the interaction with surfactant.  Would other viruses respond at higher surfactant concentrations?

Like most science papers this one is interesting and raises some real concerns.  But, as is so often the case it leaves a lot of good questions without answers.  In the current publish or perish climate leaving a lot of unanswered questions is a survival requirement in academia.  The only solid conclusion I can draw is this paper is for sure not a "green" flag for this surfactant when honey bees are working the crop, but also not a "red" flag.  More like a rather large "yellow" flag that begs for more work.  Particularly field data that shows how much honey bees actually bring back to the hive and is it brought back on pollen or nectar or both and what is the concentration in larval feed produced by workers.  After all, it makes little difference how much it harms larva if in the field they are not exposed or are exposed but to much lower concentrations that may not cause a problem.  On the flip side if field exposed bees produced larval food with 10 ppms of surfactant I would not want my bees exposed.  I think the suppliers of this class of surfactants better fund a bunch of work to see if the products are bee safe real fast.

Dick

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