>Queen loss over six months was: control – 50% (inexplicably bad);
>10 ppm – 45%; 100 ppm – 31%.

I remember this study but I don't recall if it was discussed in this
forum. It is important to notice that HALF of the control queens were
gone after six months. With the 10 ppm the number was almost the same.

100 ppm is the maximum EPA tolerance for coumaphos in wax and I don't
think it represents what you would expect to find. I seriously doubt
whether queen breeders would use coumaphos on cell builders, anyway.

Most queen breeders use either plastic cell cups or wax cups made from
high quality capping wax. Queen rearing operations are very sensitive
to chemicals and I believe breeders are conscious of these concerns.

I realize supersedure rates are high, but I would suggest there is
some other cause besides coumaphos, especially when you notice half of
the untreated queens were gone in less than a year.

-- 
Peter L. Borst
Ithaca, NY
USA

http://picasaweb.google.com/peterlborst

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