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/
Lucky you. None of our local feed stores carry apiary supplies. -K
I have used screen bottom boards for about 5 years now and have never had the bees build comb on the bottom of the screen. As far as wintering, I use a plastic (political sign material) to seal off the bottom during the colder months.
My opinion on feed stores carrying bee supplies is not good. We bought our supplies from our local chain feed store when we first started, got everything setup, then called back with questions and they told us they couldn’t help us because none of the employees knew anything about bees. We then found a local bee store that was owned and operated by beekeepers and they were super helpful, even though we didn’t get our supplies from them in the first place. Obviously, we now get all our supplies from the local bee shop. If you have a local bee store near you or even if you order online, I would suggest you use someone who knows about bees so you have help after you buy the product.
We have been using screen bottoms for about 10 years (not uncommon around here) and we have never had an issue.
I switched to screen-bottom boards with oil-filled trays that slide underneath (West traps) because we have problems with small hive beetle. The adults try to hide in the bottom of the hive and get caught in the oil, and any larvae heading out to pupate also get trapped. When I clean out the traps, I also spot mites in the mess so hopefully they help on that problem as well. The bees have never built comb on the bottom.
I use the screen bottom board with a slatted rack for 3 years now. I love it & the bees love it. They seem to be able to control temperature better and are able to clean better.
I live in Northern Michigan in the Upper Penninsula and we get sub-zero days in the winter. I use a screen bottom board on my hives throughout the winter and have not had an issue with the bees freezing to death. It’s not the cold that’s the problem, it’s condensation buildup that then falls back down on them as it freezes and melts.
In addition to the screen bottom board, I also put a shallow box on top with cedar chips that help to collect the moisture. I check it a couple of times throughout the winter and if it’s getting too moist a change out the cedar.
I also insulate them by putting a 2″ foam board on all 4 sides of the box (not covering their entrance.)
I’ve also never had them build comb on any of the three hives we have.