Re: Huge mite drop
Honey bees pay attention to the length of days. The last week in June is the longest length of days, the summer solstice. By the first of July the queen has started reduced egg laying, and it gets less and less eggs per day, and in many places actually stops, by the winter solstice at the end of December.
The varroa mites don't pay attention the the length of days. The varroa mites reproduce inside of capped bee pupae, slipping in the day before the larvae is capped. There is an average of close to 2 mites raised in each bee pupae that gets infested.
As the queen laying and therefore brood rearing slows during the last half of the year, the percentage of varroa per brood number increases. The end of September is the fall equinox, and at that time the bees really start reducing brooding, over and above the slow down they've been having since the end of June. The varroa have been increasing in numbers all along. By the time September and October get here, the mite percentages per brood has really exploded. By this time, it can become quite apparent to the beekeeper that something is not quite right in the beehive.
I have found that I can not go treatment free here where I am in this location with the genetics of bees I have been getting in the area. I must treat, or I will experience very heavy hive losses, and the hives that do live through into March, are not worth counting as a hive.
Some areas with some bee genetics are reported to not treat and also get a good honey crop. Most areas and bee genetics can not do that, not that I've seen or heard of. I've had to make a choice, my choice is to treat and change my management practices in order to have any decent looking hives in March time frame.
20+ years, raise my own queens, feed when needed. I treat, but have not perfected varroa management yet.