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ATTN: New beekeepers with screened bottom boards

126K views 213 replies 97 participants last post by  Gray Goose 
#1 ·
Every year, EVERY year, every YEAR, there are multiple posts on beesource saying to the effect, "I installed my package of bees and they absconded."

If you feel like you must use a screened bottom board, KEEP IT CLOSED UP AT LEAST UNTIL THE HIVE IS RAISING BROOD.

I'm not going to try and pursuade you from using screened bottom boards, I'll just say I don't see a need for them. Use what you want, but keep them closed up.

If the mods do not care, I'll bump this post up every week or so in hopes of saving someone a package or two of bees.
 
#81 ·
No one doubts that bees use water evaporation to help cool the hive, the problem is most beekeepers don't understand how the process works in a brood nest. It is not like an air conditioner, nor a water cooler, it is like the fan blowing air across the skin of a person that is perspiring, it cools the surface of the skin, not the air some distance above the skin.

Bees fan to move the air over the surface of the comb, the water evaporates and cools the surface of the comb and the area of the cells. The bees have no intention of cooling the air passing in and out of the brood chamber, just as bees have no intention of heating the interior of the hive in the winter. They keep different areas of the brood at different temperatures depending on if the brood is worker or drone, and I believe they can do this with less effort over screened bottom boards than with solid bottoms.

Have none of you had a colony melt down in the summer? Those of you that have had this happen, was the colony on a screened or solid bottom? When a colony beards, and it is the only colony that does so even when others are as strong or stronger, is it on a screened or solid bottom? Bees don't exit the hive to remove their added body heat except as a last resort, and the idea that they re-enter to help cool it is hogwash. If they could have cooled it by remaining inside they would have done so in the first place.
 
#82 · (Edited)
It is not like an air conditioner, nor a water cooler, it is like the fan blowing air across the skin of a person that is perspiring, it cools the surface of the skin, not the air some distance above the skin.
If the [now] humidified air is not exhausted from the room the person is in, then I agree with the above. The effect of the fan is very transient, and only lasts as long as that room's air can hold additional humidity. If there is no outside air exchange, the cooling effect will stop when the air can not hold more moisture.

But that is not how evaporative cooling works in a hive. The bees push the humid air outside, and draw drier air in so the process can continue, and yes, lower the air temperature below the ambient outside temperature.



Bees don't exit the hive to remove their added body heat except as a last resort, and the idea that they re-enter to help cool it is hogwash. If they could have cooled it by remaining inside they would have done so in the first place.
Hogwash? You are saying that bees don't react to changed hive conditions?:scratch: :s
Remember, my earlier comment was with regard to the beekeeper changing the position of the screen closure board and consequently introducing additional warmer outside air into the hive, in which case the bees are adapting to the changed hive conditions.

.
 
#83 · (Edited)
Here is a tech sheet on an evaporative cooling system:
http://faculty.caes.uga.edu/pthomas/hort4040.web/Carolina Cooler SpecTech sheet.pdf

This system is suitable for greenhouses and facilities like poultry barns, where cooling below ambient temperature is desired, but full blown air conditioning is not warranted. Note the map that estimates reasonable potential cooling in different areas of the country. Even in what is perceived as the relatively humid South, for example in Concord NC (near Charlotte) there is a potential 12 degrees evaporative cooling available.

Yes, this a marketing piece, and of course daily conditions vary, but evaporative cooling below ambient temperature is not just a theory, it is reality. There are many hundreds of poultry barns across the South taking advantage of that process.

.
 
#84 ·
We have dry air out here, I can get up to 30F cooler in my house with a swamp cooler.

air flow 101....cold air sinks hot air rises, put on a SBB and all the cold air flows out the bottom
 
#89 ·
Let me make sure I understand before doing what I'm thinking of doing .....

I have a ScBB on my 1 hive (from a package 3 weeks ago). Colony seems to be doing well (as of my inspection last week) but can/should I place a flat board underneath the hive? Would it help the bees having additional darkness now? Or would it be disturbing - altho' maybe a welcomed change as opposed to unwelcomed?

I thought of using my stickyboard to make added darkness for the colony, but I see that my hive (for a reason I don't get) doesn't have the space under the "landing zone" by the entrance for placing a stickyboard there. A flat board seems to be my only option.

Any opinions as to how to go? Thx .....

[interesting thread, too -- good to see the various opinions, and I like to see a general consensus among the experienced people; gives me some confidence]
 
#90 ·
Look, I personally think this thread has evolved to being very uninformative and snide. What it boils down to is you can close off the scBB when you want to; you have a choice. With SBB you don't. Again, it is up to you as a beekeeper to choose and experiment and educate yourself as to your particular environment as to where you are located.
 
#91 ·
I agree that it's turned snide and so have I about this thread. It wasn't started that way though. It was started to try and help new beekeepers, then all the ScBB fans came on the thread posting about how good beneficial they are. The problem with a new beekeeper educating themselves on what to buy is that they don't yet know enough to do that.

So to my question. What problems has a solid bottom board ever caused that a screened bottom board would fix? Please don't say keeping the hive cooler. We had over 120 days of high temps over 90 degrees last year and my bees did just fine during the summer. They are pretty good at ventilating as needed.
 
#93 · (Edited)
Here is an example of a new thread (started 9 pm last night) with an 'open' screened bottom board problem that the intent of this thread is referencing:
http://www.beesource.com/forums/showthread.php?336026-Bee-cluster-under-a-new-hive

If we were to list all the similar threads here, it would be a looong list. :p


Note that I make a distinction between solid bottom boards that have a 'screened' oil tray above the solid bottom, and those that have screened bottoms 'open' to the environment. For an example of a solid bottom with a screened tray, see Rusty's plans here: http://schoonerbay.net/rustysbees/ipm.html

.
 
#97 ·
I have one out yard that is bad for SHB. Trees, soft sandy soil, no full sunlight. Others in the area loss hives to SHB.

That's great your numbers are low. :) The old adage still stands, all beekeeping is local. lol
 
#98 ·
A screened BB is a tool. Just like any other tool, it can be used wrong. I my area using it as a cooling tool for the hive is ridiculous. Since weather records have been kept, the temperature has only hit 100 degrees F. two or three times total. Even 90 degrees only happens a couple of times a year and most years not at all. A really hot day here is a cool fall day in Texas. Most of the people that I know around here, including myself, use them for varroa monitoring. No, they do not give spot on information about varroa levels but they do give information regarding the presence of varroa. The last 5 years of using them has shown me that I may see 1 or 2 in a weekly drop but come July - August, the rate increases to 10-15 per day and it is treatment time. If I see significantly more than the usual 1 or 2 in a week, it is time to do an alcohol wash and find out what is happening. Using the screened BB does not mean you can stop doing other forms of varroa monitoring but it gives you another tool to help keep track of them.
 
#105 ·
Sorry all, but I just built screened bottom boards with slide-out trays. Cor-plast trays with front 'handles' that seal the plenum below the screen.
It's like a solid bottom board for Fall/ Winter/Spring and a nicely ventilated bottom for Summer. Best of both worlds I think. I can put a mite-matrix sheet on the cor-plast to do mite counts pre-treatment and post treatment. Seal up the hive for OAV or other treatments. A million ways to make things work, folks.
Brian
 
#108 ·
So I've been reading through the posts and I am trying to learn. If your hive is thriving, what is the downside to a screened bottom board? I've picked up that they may cause new colonies to leave, but past that point are their drawbacks to it? I live in Charlotte NC area so winters are mild.
 
#109 ·
I've picked up that they may cause new colonies to leave, but past that point are their drawbacks to it?
I was going to write a comment here and I did it before.
As many of you know and probably experiencing as I do, this is a hot swarming period, so both of my hives swarmed (one of them even twice - last was yesterday).

My 1st hive swarmed and I put them in the hive, and I like SBB. I didn't close it thinking that bees will acclimate there since they swarmed and basically they were prepared to live on the tree brunch (open space), but checked in 10 days, they didn't do much in the hive and out of lots of them there were about orange size ball of bees.

The 2nd hive swarmed and I caught them and this time I closed the SBB and also put entrance reducer to 1", so hopping they will do better.

1st hive swarmed again yesterday and I had to let them go, since they were on the tree very high and getting them from the tree was dangerous.

I am still for SBB, but as I experienced, with new colonies it probably need to be closed for a while.
 
#113 ·
I don't want to rephrase the question because I already have a screened bottom board, my hive is doing fine and I am new to all of this. So I would like to know if there are potential problems going forward. When I create a new hive I can ask the question as you've rephrased it, but for now I'm trying to understand if I'll have problems going forward and should incur the extra expense of another bottom board now.
 
#114 ·
No need to buy anything special - just close off the open screen. Lots of 'found':) materials could do that - a piece of scrap plywood, a piece of corrugated plastic signboard ("political signs"), etc.

Read the threads at the link i provided to see what issues may come up with an open screened bottom. One obvious one is that open screen bottoms impede the bees' efforts at managing their hive environment. Evaporative cooling makes it possible for the bees to reduce temperatures below the ambient temperature on hot days. A big hole in the hive bottom impedes that effort. Read those links. :shhhh:
 
#115 ·
Kcnc1, remember that what you read in these posts are nothing more than personal likes, dislikes, and beliefs.

The only controlled studies done have shown that Open Mesh Bottom Boards ("Screened Bottom Boards") perform as well or better than solid bottom boards in hot summer conditions. In winter in Iowa, using Russian bees, the colonies with open bottoms survived as well as the control colonies, however they used 20% more food during the winter.

Google Doug Somerville's study done in New South Wales, Australia. This was a 2 year study done with 200 colonies. It showed 15% more honey production than the solid bottom control colonies, and stressed colonies don't produce more honey than non-stressed ones do.

There have been no studies done, to my knowledge, on the cause of package bees or swarms absconding. I doubt that screened bottoms are the cause, even though some say that is the cause. I have used both solid and screened bottoms and I don't have swarms absconding with either one. However, it would be prudent, in cold spring conditions, to use a small hive for a small colony.

Whether or not you use open, or solid, bottom boards is your decision. Successful beekeeping is done using both types of bottom boards. Don't allow yourself to be spooked into thinking you must have a particular hive configuration to be a successful beekeeper.

A Canadian beekeeper wrote an article in Gleanings in Bee Culture in which he said the honey crop is more dependent on the man than the type of hive used. That was written around 1900, and it is still true today.
 
#118 ·
Google Doug Somerville's study done in New South Wales, Australia. This was a 2 year study done with 200 colonies.
Well, I for one, would like to read that study.

Searching Google for ...
Doug Somerville study screened honey New South Wales, Australia

... doesn't yield any likely results that appear to show that. Several variations on that search phrase weren't successful either. There are a number of bee related pages/studies with Doug Somerville's name attached, but I couldn't find one that said that open screened bottom hives produced 15% more honey.

I'd be grateful if someone could post a link. :)



[If one isn't quite sure how to post a link here, even just a domain name (like "beesource.com", for example) would be helpful.]
 
#116 ·
Yes read what Rader posted links to and also take note of posts that talk about pollen being found on the "sticky" board under the screen. I never see pollen on the inside of my solid bottom boards. The bees apparently salvage what's dropped when they can get to it. Sure they may only drop 2% of what they bring in (SWAG) but how many of us would shake nectar out of honey frames and waste it?

Screened bottom boards were supposed to help with varroa mites but they don't. Then they're supposed to help with hive beetles but I don't think they do that based on the hives I've seen with ScBB's. If a beetle can fall through the screen it can gain entry to the hive through the screen as well. It's gotta work both ways.

Well, since the original 2 theories for using them have been debunked, in my mind at least now users want to say they help with ventilation. That's hogwash. Bees don't need help with that. They power ventilate the hives and use evaporative cooling all by themselves. They don't need a wide open bottom to impede their control of the air flow.

But then users also say you can monitor mite levels using trays under the hives. Yes I suppose you can but you can also put a piece of coroplast inside the hive with a solid bottom board or perform a mite wash in about 5 minutes per hive and get a much more accurate number.

The ScBB's do cost more though, so people can brag about that
 
#157 ·
Screened bottom boards were supposed to help with varroa mites but they don't. Then they're supposed to help with hive beetles but I don't think they do that based on the hives I've seen with ScBB's. If a beetle can fall through the screen it can gain entry to the hive through the screen as well. It's gotta work both ways.

Well, since the original 2 theories for using them have been debunked, in my mind at least now users want to say they help with ventilation. That's hogwash.
Original 2 theories ? I don't think so. A screened bottom board features in Langstroth's 1852 Patent - so it's hardly a 'fad' as someone had suggested earlier in this thread. It's incorporation was intended to provide a means of ventilation, controlled by means of a partial obstruction within the hard-bottomed shim - a method some of us have already adopted with success, and I suspect without prior knowledge of Langstroth's Patent. (I only read my own copy of his Patent earlier this week :) )
LJ
 
#117 ·
AR beekeeper, so they work as well as solid bottom boards according to studies? Well except for them using more honey in the winter. That's not good. But it's interesting that something that costs more and apparently causes problems with new package or swarm installs, works as well as something cheaper and as time tested as a solid bottom board.

We don't have to do blind trials on packages absconding, just read beesource on Monday through Wednesday every week during package install season.
 
#119 · (Edited)
Search for Screened Bottom Boards, Rural Industries Research and Development Corporation, study by Dr. Doug Somerville.

When I said 15% more honey I may have misspoke, the actual statement is 15% weight gain.

You may want to watch the video on youtube, Screened Bottom Boards by Doug Somerville.
 
#120 ·
OK, I believe that this link is to the study mentioned above:
https://rirdc.infoservices.com.au/items/14-061

(At first glance, they want you to pay to buy a printed copy for $25, but you can download a PDF for free.)
You most likely will have to download the document to your local PC and then open and read it locally.

Everyone is free to read the study themselves. What caught my eye is this ...
The results of this study suggest that there is no significant difference in productivity of bee hives with the use of screened bottom boards compared to conventional bottom boards. Thus any conversation on the use of screened bottom boards should be focused on their impact on varroa mite populations.

(snippet above from page #29)
https://rirdc.infoservices.com.au/items/14-061
[hr] [/hr]
Just in case the study above is not the one AR Beekeeper had in mind, here are some other links:
Screened bottom boards are considered an effective weapon in the management of Varroa and the project, run by Dr Doug Somerville from the NSW Department of Primary Industries, compared the two options in a variety of seasonal conditions and locations.

Spokesman for the R&D Program, James Kershaw, said many beekeepers have been concerned that screened bottom boards expose honey bee colonies to drafts and greater variation in hive temperature.

“The results of this research demonstrated no difference in the productivity of honey bee colonies. In fact, the screened bottom boards provide many advantages for beekeepers, not just in the management of Varroa,” Mr Kershaw said.

http://www.rirdc.gov.au/news/2014/12/09/screened-bottom-boards-provide-varroa-management-option
Can bottom boards help fight the mite?

Dr Somerville said the concept has been around for a long time in other countries where Varroa mites are already endemic.

“There are many designs available and they cost a little more than traditional closed hives, but they may possibly better prepare beekeepers to live with Varroa mite if and when they arrive on our shores.

“Alone a screened bottom board may offer 5-30 per cent control which can then be combined with an organic or synthetic chemical treatment program to acheive the greater than 90 per cent control needed to maintain hive productivity.

“This very simple technology is at work 24 hours a day, 365 days a year as a part of an integrated pest management program,” said Dr Somerville.

Australia is one of the last countries free of the mite which has wreaked havoc across the globe, and many scientists believe it will reach our shores sooner rather than later. It is likely to decimate wild European honeybee colonies and severely impact managed hives – not to mention the estimated 65 per cent of agricultural production in Australia that is reliant on honey bees for pollination.

http://www.rirdc.gov.au/news/2011/09/07/can-bottom-boards-help-fight-the-mite-
There are various mentions of varroa in the above links. Let us be clear here, there were not varroa in Australia at the time these studies were prepared.
 
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