Screened Bottom Boards

Lesgold · October 29, 2023, 06:38:37 AM

OK guys,

Many people around the world use screened bottom boards as part of their varroa management strategy (or so I have read) Any advice in relation to design and essential features? In looking at many of the options available, I can see that there is a bit of work involved in constructing them so jigging up would help to save time. To buy #8 hardware cloth in Australia is very difficult and quite expensive and would make the bottom boards a pricey item to make. Do you guys know of any alternatives? I?ve got one in mind but would like to explore every avenue. Thanks in advance for your guidance.

Cheers

Les

Terri Yaki · October 29, 2023, 09:46:11 AM

To screen or not to screen, that is the question. I am but an aspiring beek but I have been reading up and absorbing as much as I can in preparation and have been paying attention to the screening debate. From what I have read, I have concluded that I will not be screening. So, before you decide to do it, I would recommend hearing what others report on the results and affects.

animal · October 29, 2023, 10:02:25 AM

is 3mm not a common size there? 3mm is available in US but very expensive and hard to find except in stainless. It seems like the slightly smaller size ( 0.175 mm ) wouldn't matter with varroa. I ran into the same problem looking for 4mm here as you have with #8. For that matter : Can a bee get through 4mm ?

This is what I ended up with for hive beetles (with the idea of it being useful for varroa as well). It works well on beetles. It does use #8, though I thought I needed slightly larger for the beetles to fall through. Turns out, the bees chase them through.

https://beemaster.com/forum/index.php?topic=56595.msg519130#msg519130:~:text=Gender%3A-,Re%3A%20hive%20beetle%20control%20opinions%2C%20please,-%C2%AB%20Reply%20%2337

the drawer opens to the side because of the way my steel tube frame hive stand is made. It's completely open at the bottom when drawer is removed.

Terri Yaki · October 29, 2023, 12:01:53 PM

Couldn't you just buy some metal screen and spread the weave apart with a proper sized drill bit?

animal · October 29, 2023, 12:16:33 PM

Teri, you could use a drill bit or awl to do every other one but it would be time consuming and hard to do without putting more "waves" in the material unless you had a support jig of some kind. (some of us have psychological problems that interfere with intentionally making the screen non-uniform

)

Terri Yaki · October 29, 2023, 12:19:03 PM

Quote from: animal on October 29, 2023, 12:16:33 PM
Teri, you could use a drill bit or awl to do every other one but it would be time consuming and hard to do without putting more "waves" in the material unless you had a support jig of some kind. (some of us have psychological problems that interfere with intentionally making the screen non-uniform )

I'm the oddball on that. Out of sight, out of mind. A lot of my buddies are OCD and I take a lot of heat for my sloppiness.

animal · October 29, 2023, 12:22:15 PM

but the bees see it

The15thMember · October 29, 2023, 03:42:22 PM

I have both screened and solid bottom boards, and honestly, I don't think I'd buy more screened boards, because they are more expensive, and they have very little bearing on my varroa management. I mean yes, it is rewarding to see varroa drop through a screened board after treating, but counting mites on bottom boards is both harder and less accurate than a sugar roll/alcohol wash. And if you are treating, you are killing the little jerks whether their bodies drop through the screen or just onto the floor of the hive. There are positives and negatives to both styles of BB, but I've personally found the screened boards to be not worth the extra cost.

Kathyp · October 29, 2023, 05:04:28 PM

For swarm catches they are fantastic. I have used both. The only advantage to the screened for regular use was that I seems to have less moisture in spring when it's really wet. I closed them in winter. You probably don't have the rain issue that we have here and I didn't see a big mite control + in having the screened boards. If it ain't broke...

The one thing I highly recommend as you guys get varroa, is that you treat for it. I know a lot will disagree, but I think one of the reasons ours are so bad in some places is that there's to much "all natural" stuff going on and mites are spread around like crazy. + now that everyone wants to save the bees, there are beekeepers coming out of our ears!

Lesgold · October 29, 2023, 05:42:12 PM

Interesting comments. I have a couple of commercially made screened bottom boards that I?ve been using for years. One is in a poly hive and the other is a galvanised steel base. I also have about 5 bottom boards that I made which use a series of slots in the base for ventilation. The Bluebees board is what I?m talking about here. It has a series of semi circular sections or ridges that the bees walk on. Beetles tend to be chased out through the slots and all debris falls through the slots. It is one bottom board that never needs cleaning. I have been reading that screened bottom boards have a small impact on varroa numbers and are only partially effective. Is that what you guys are finding? The information that I?ve been getting is basically saying that it is only one minor component of a management system to help control varroa. If the information I?m getting is wrong, please let me know. I want to do as much as I can to prepare for the invasion that will hit. As far as the cost is concerned, that is a real consideration. I have been using an aluminium mesh for years in some of the beekeeping projects that I?ve made and it may end up as a cheaper option. I used some of this screen recently on the pollen trap that I made. Bees can?t get through it but small hive beetle can. The issue I had with the aluminium screen was the fact that I couldn?t buy it in the widths that would cover a bottom board. This meant that joins were required which became problematic. I found out a couple of days ago that it is now available in sizes that will suit my needs. Although much softer than stainless, it is very easy to cut with hand tools and bends readily. If I buy a roll, a piece for a bottom board would cost less than $4. I?ve read a lot about SBB?s over the years and I can see good arguments both for and against. The climate that you live in could tend to influence any bias one way or another. In my own situation, I leave the vented and screened boards open all year round. Observations on my part have only been anecdotal and not recorded but here goes. The hives have always been strong and healthy. I have noticed no difference in the strength of hives with or without SBB?s. The only exception to that is the poly hive that I?ve had for about 10 years. It is always a bit larger and stronger on average than the rest of my hives. Condensation is always less in these hives. Small hive beetle numbers appear to be consistent with beetle numbers in all other hives. The numbers appeared to be a bit lower in the hives with Bluebees bottom boards. Honey production appears to be similar to hives with a solid bottom. Again, the one exception is the poly hive that tends to end up with a higher honey yield than other hives. (Not always but it is always near the top producer). So in summary, in my situation in a temperate climate, a screened bottom board has no disadvantages but the question still remains. Will it have some impact on varroa? If the answer is a definite no, then there is no reason to change. If there is only a minor impact on varroa, a change is definitely an option. I have been designing a SBB that should be simple to make but I would like more feedback before I get started.

The15thMember · October 29, 2023, 06:02:17 PM

I have seen zero noticeable mite reduction in colonies with screened BBs as opposed to solid; in fact this year, I don't think I treated a single colony on a solid board, whereas I treated 5 on screened boards. There are other factors at play of course that made certain colonies struggle more than others, but the screened boards in my experience don't help prevent or mitigate a varroa infestation in any significant way. The amount of live mites that fall through the screen by happenstance is just too small to make a difference, for my bees at least. Now, if you had very hygienic bees, that were actively cleaning the mites off, would it make more a difference? Maybe, but for my bees, it doesn't seem to matter what BB they are on, as far at mites are concerned.

Lesgold · October 29, 2023, 06:18:10 PM

Thanks Reagan. That sort of feedback is great. I wonder if others are finding similar results.

animal · October 29, 2023, 08:22:42 PM

Wish I could help, but I'm too much of a newbie and haven't seen varroa yet. The bottom board/tray I'm using has done well on beetles. Only a few in the kill tray at first, then a wave of a huge number, nothing for awhile, then a few hundred, and maybe 2 or 3 in the last month. Haven't seen any actually in the hive in months. Planning on changing the bottom drawer/tray to 6 steep funnels with a female thread so that disposable water bottles can be screwed to them. The oil tray is a bit messy for clumsy me... but I'm just a tinkerer with one hive and an empty spare.

Michael Bush · October 30, 2023, 10:55:48 AM

I don't use SBB on my hives, but I use them when moving hives and when catching swarms. I have never seen any difference on Varroa.

Terri Yaki · October 30, 2023, 11:31:54 AM

Quote from: Michael Bush on October 30, 2023, 10:55:48 AM
I don't use SBB on my hives, but I use them when moving hives and when catching swarms. I have never seen any difference on Varroa.

And what are the benefits of using them when you do?

Michael Bush · October 30, 2023, 12:40:24 PM

Ventilation. Bees produce a lot of heat when you are transporting them. Though normally I suspect SBBs make it harder for bees to cool the hive, when you are bouncing them around they tend to lose interest in cooling and their excitement can make them overheat. All my bottom board are minus an entrance (I run all top entrances) so I can put them on the bottom and also on the top when I'm moving hives.

Lesgold · October 30, 2023, 04:30:16 PM

Thanks Michael. I was hoping that there was going to be some benefit but I?m not hearing much in the positive. That in itself is good as I don?t want to waste time building something that doesn?t appear to be living up to the hype.

Michael Bush · October 31, 2023, 07:54:57 AM

I don't think a SBB is bad if you put the tray in. It may or may not be useful for SHB. If you keep the tray in, it might be useful to monitor mite drop. But I never saw any difference for Varroa control. Also, if you leave the tray out, there is evidence it makes Varroa worse. They reproduce better at slightly cooler temperatures. The only significant upside is they rot more slowly since they always drain well...

BeeMaster2 · October 31, 2023, 08:16:31 AM

Les,
I have SBBs on on my hives. I didn?t build them for the mites. They are great at killing thousands of small hive beetles if you put oil in the trays. When I had my hives in at my Jacksonville house, they were in total shade. By my third year I had 12 hives and a neighbor half a mile away had 5 hives. We both were having to wash out the trays every 30 days, they would bee solid black with SHBs and they stunk. That?s 17 hives killing thousands each for 8 months. The next year we both quit using the oil because we were not seeing very many in the trays anymore. The great thing about the oil trays is that they kill the adults, the larvae that drop out of the hive to pupate and the eggs the bee?s clean out of the hive.
Jim Altmiller

Ben Framed · October 31, 2023, 10:42:27 AM

Quote from: Lesgold on October 29, 2023, 06:38:37 AM
OK guys,

Many people around the world use screened bottom boards as part of their varroa management strategy (or so I have read) Any advice in relation to design and essential features? In looking at many of the options available, I can see that there is a bit of work involved in constructing them so jigging up would help to save time. To buy #8 hardware cloth in Australia is very difficult and quite expensive and would make the bottom boards a pricey item to make. Do you guys know of any alternatives? I?ve got one in mind but would like to explore every avenue. Thanks in advance for your guidance.

Cheers

Les

Les I was thinking of the gutter material that you told us about last year. Would this stuff work in this application that you are thinking of now? Perhaps you could cut it to the proper links, line it up and wire the strips together to form the proper size screen bottom which you seek and add some type of cross support to eliminate sag?

https://beemaster.com/forum/index.php?topic=55456.msg507422#msg507422