A bunch of posts back, Mike said:

> Coumaphos...of course...killed all the queen cells. What I found
> interesting was that Fluvalinate and the controls were statistically identical.
> There was no effect on queen cells, virgins, ability to mate, or viability of
> semen.

That's not surprising at all - Coumaphos is an organophosphate.
The rest of agriculture is moving away from the use of organophosphate
pesticides due to the cumulative neurological damage that results from
the cumulative impact of minuscule levels of exposure. Beekeeping may
be the last segment of agriculture to still be using an organophosphate.

Fluvalinate is a much more simple pesticide.
Not a "nerve agent" at all.