Re: Screened bottom board?
I'm not familiar with the article, but I can already tell that I would disagree with the author 100%. I'm not saying that a screened bottom board will solve all your Varroa problems but they have so many advantages. They improve the ventilation in your hives, they provide a way to monitor your infestation levels, they over-winter better, and they provide a 100% treatment-free reduction in mite levels. I think they are one of the most important developments in modern beekeeping and if you're not using them, you should be! Switching hive bodies during early spring should adequately resolve upward bee movement.
...This, and my heart, and all the Bees
Which in the Clover dwell.