Peter Borst writes:  “[this is for a northern climate. in warmer climates 
it may need to be earlier still]”

  I would have thought that in warmer climates you would have a broader 
window of time within which to treat since brood production is able to 
continue further into the later months.  I live in north western Washington 
State and I do feel I have to treat at least by mid September not only 
because I want to give the bees time to produce more healthy bees for 
winter, but because the weather starts to work against you with Formic Acid 
past that time.

Steve Noble

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