Board bottoms

Here's the new-style anti-varroa bottom board that's growing in popularity in Britain. It's a wire mesh with room for a sturdy plastic tray insert. It's somewhat similar to the screens used for some ten years, but the crucial difference is that the tray is rarely left in place -- it is simply used for occasional monitoring purposes. It costs about £40 ($70).


 

The idea is that without the tray in place, varroa that are groomed off or fall off cannot climb back into the hive and onto the bees. The tray is put in place to monitor varroa drop at critical or suspect times. If you smear petroleum jelly around the edges, the varroa that drop shouldn't be able to crawl away.

The older trays that were left permanently in place proved wonderful breeding grounds for wax moth and have now fallen out of favour.

But don't the bees suffer from no protection from the elements when the trays are not in place? Apparently not. There's a belief that the bees actually benefit: although the colonies can seem smaller in spring, it could be that the weaker bees don't make it and that the strong ones then build up the spring colony very quickly.