I love the fact that bee keeping supplies are becoming mainstream in most local feed stores. When we first started beekeeping we’d either have to trek a 2 hour trip to the nearest hive supply company or order things online with often hefty shipping costs.
We pretty much have everything we need for our current bee set up, but every time we go to pick up chicken or goat feed, I still like to wander down the beekeeping aisle and see what’s new.
Recently, I noticed something I’d never seen before. Amongst the hive box parts that are sold individually or as a set, they were offering a bottom board with a screen bottom instead of solid.
I’d never seen this before. Intrigued, I decided to do some research when I got home.
My gut was that the screen was designed to provide ventilation, but after reading a few articles I realized that there was a bit more to it.
The screen design was first put in place to help count the effectiveness of Varroa mite treatments. The researchers would treat the bees with an application, then count the dead mites that had fallen off the bees and through the screen.
In the study, they also set up control hives with no treatment. These hives were also fitted with the screened bottom.
The researchers found that with the control hive, often live mites would simply fall off through the screen. If a solid bottom board was in place those fallen mites would still be present in the hive and easily re-attach themselves to a new bee.
While not completely effective at eliminating mites, it the screened bottoms do help reduce some of the infestation, (around 20%).
Screens also help with ventilation in warmer months and help to prevent moisture buildup in the winter.
They also help to keep the hive cleaner as bits of dead bees, soiled wax and other debris can fall through the bottom.
In screen bottom hives often the bees will begin building comb under the hive and incorporate the screen into the wax workings of comb and honey. To the bees, the screen allows them to pick up on the scent and pheromones of the hive inside and they don’t really see it as a barrier.
If this happens, it really nullifies any benefit of the screen as the new comb blocks the holes that provide ventilation and unwanted material from falling through.
It can also create comb that is difficult to remove and difficult to harvest honey from.
The bees working on this exposed hive do not benefit from the protection of the enclosed boxes.
If you live in a climate that has cold winters, while the screens provide moisture release, they don’t hold the warmth like a solid board. This can make your hive susceptible to freezing, and may delay honey production as the bees wait for the weather to warm.
We live in Michigan with some pretty severe winters so I’m not sure if we’ll be switching our hives anytime in the future, but if you live in a warm climate and have a problem with mites, I think it’s definitely something to consider.
There’s Always Something New to Learn by Ross Conrad http://www.beeculture.com/screened-bottom-boards/