Mark, the last I heard, we can't use it here in the States, something about danger to post office workers. I'll be happy if things are changed though. I'm still safe with checkmite, most of the other beekeepers have given up on bees, and the ag commissioner told me that I was the only one in the county using check mite, at least legally. At one apiary, I've had to treat all my hives last month, as someone a few hundred yards from me lost every single one of his hives due to ineffective treatment. My biggest apiary, where I have 60 hives spread around a large lemon farm is still fine, although I've seen a very few bees with shrivelled wings. This puts me at 10 months from my last treatment, and it really isn't more expensive than the figures you gave for formic acid treatment. Still, I'd like something in reserve. Regards Tim