> Miticides are complicit with queen issues including fertility.

When varroa arrived, our rate of queenless colonies at the end of the
season went up by a few percent--enough to be noticeable.  This was likely
prior to fluvalinate residues becoming an issue.  This suggests that simply
having varroa present raises the rate of failure to supersede.

We also must consider the prevalence of *Nosema ceranae*.  Although I
haven't seen a correlation between queen loss and *N ceranae*, it's
invasion of the U.S. bee population in the first decade of this century may
be a contributing factor.

The above factors aside, I tend to agree with Rob that residues in the
combs of miticides and ag chemicals likely have a great deal to do with the
current high rate of queen loss. This opinion is supported by personal
observations in my own operation, in which we haven't used synthetic
miticides for many years, and have little exposure to ag chemicals.  So we
function as a sort of control group.

Our rate of queen loss is very low, in the single digits each year.

A (I believe yet unpublished) study by a postdoc working with Juliana
Rangel (my apologies for forgetting your name) found that queens reared in
cells dipped in beeswax contaminated with field-realistic levels of
fluvalinate and coumaphos later produced less QMP and attracted smaller
retinues of attendants.  This would be a plausible cause for supersedure.

An interesting experiment would be to stock two groups of hives with queens
from the mate out.  One group of hives would contain "clean" combs, the
other typical combs from a commercial operation well contaminated with
miticide and pesticide residues.  Then measure the rates of queen survival.


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

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