Randy, I think you incompletely read the figures in the Tsvetkov paper.  You said:


“I hope that the pasted graphic of her Fig.  2D shows below.  The experiment,which among other things, tracked the presence of a laying queen in 4 treated and 5 untreated control colonies over 90 days.  In the treated group, there were zero laying queens on Day 80, but one was laying again by Day 90.”

If you read the caption to that 4 part figure, you’ll see that only part B has just 4 and 5 colonies.  (Part B dealt with hygienic behavior).  Parts C and D have 25 colonies in each group, while Part A dealt with individual larvae.  I was puzzled about Part B because the C and D parts of the figure deal with 25 colonies, so why only 4 and 5 colonies in Part B?  However as usual it pays to read the whole paper, not just look at the figures.  So in the text, we read that these different parts of the figure were constructed from data accrued in different years.

Figure 2C (hygienic behavior in the field):  25 control and 25 test colonies (near treated corn) were evaluated and there was a highly significant loss of hygienic behavior in the treated colonies, from about 45% mean in the controls, to about 37% mean in the test colonies....a roughly 33% decline.

Figure 2D:  Proportion of the treated colonies with a laying queen declined from 90% to about 25% within 90 days and did not recover.  Proportion of the controls with non-laying queens went from about 77% to 60%, with one notable outlier at the 55 day mark where only 20% of the control colonies were laying.  (NOTE that those data points are averaged from 25 colonies, and don't represent individual colonies as you thought.)  The control result is pretty interesting to me because I've noticed that colonies do stop laying for a period during the summer months and then pick up again...there are of course many reasons for that to happen naturally, but the point is they should start laying again in a short time, and indeed the controls in this experiment did start laying again.  After 90 days 60% of them were laying.

Figure 3:  Neonics are twice as toxic to honeybees in the presence of boscalid, a common fungicide.  Field-realistic doses of the herbicide linuron did not influence neonic toxicity to bees.

I don’t know about California, but here in New York if queens stop laying within 90 days that is a dead colony by the following spring.  We just don’t have a long enough season to tolerate that.  So, here in NY it makes no sense to continue observing queen laying behavior after 90 days because by then it’s too late.  Of course, folks who migrate in and out of the state can probably revive a nonlaying colony by re-queening in more southerly weather that permits continued colony activity.  And possibly, in California it would make a lot of sense to extend the study beyond 90 days to see if those non-layers decided to start laying again eventually.

Again I say:  Context matters.

Christina

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