Re: Thymol and drone sterility
I used Apiguard (thymol) for the first ever time last fall, and was very pleased with the results. The bees got 50 mls paste, then another 50 mls 2 weeks later, so all up around a 4 week treatment period.
Going through the hives next spring the bees were fine with low mite levels, clearly the treatment worked well.
But - it is hard on the bees during treatment and I learned a few lessons about what not to do next time. What happens is the bees hate the smell and if the hive is weak they can be driven from part of the hive, also had some hives robbed cos the bees were too disrupted to guard the entrance properly. Also had some brood killed, plus most of the hives the queen stopped laying for a week or two.
In view of all this, personally I would not use the product during any queen raising activities, not because it hurts drones it probably doesn't, but just because it disrupts things generally and there will likely be a cost in terms of numbers of queens produced.
Like Jim I wouldn't use it spring as that's when you need the bees building up uninterrupted, but for my system anyway, it's a good fall treatment some disruption then doesn't matter long as the hive survives.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).