Should we leave varroa board under the Mesh Floor in winter?

[victor meldrew]

It

It Does if the door is left open all winter

I live in a 1930s house with a deep void under the wooden floor.
In order to prevent damp and wood rot , there are air bricks below floor level on all elevations , plus internal walls below floor level are built honey comb fashion to further assist ventilation. Over the years we have tried all sorts to reduce draughts during windy weather.to no avail.
Still conditions, it’s fine . Freezing winds suck the heat out of the house grand style .

 

[E&MBees]

I live in a 1930s house with a deep void under the wooden floor.
In order to prevent damp and wood rot , there are air bricks below floor level on all elevations , plus internal walls below floor level are built honey comb fashion to further assist ventilation. Over the years we have tried all sorts to reduce draughts during windy weather.to no avail.
Still conditions, it’s fine . Freezing winds suck the heat out of the house grand style .

My 1930’s semi is the same. I reckon my bees are warmer than me currently!

 

[Curly green finger's]

It’s a strange subject, in the past few years I have favored solid floors, for no particular reason, it started when leaving the varroa floor in place allowed a healthy wax moth breading area, that stops with the solid floor. I know it’s been discussed on the forum before and in some detail.

We monitor varroa through inspections, having so many hives give us the luxury of being able to compare hives and loads on bees, in reality if you can see the phoretic mites you need to treat.

Hi Patrick just to clarify, you monitor varroa via inspections, not sugar rolls or alcohol washes... One of my friends does this and I can see why.

 

[Erichalfbee]

Hi Patrick just to clarify, you monitor varroa via inspections, not sugar rolls or alcohol washes... One of my friends does this and I can see why.

Looking for mites on bees?

 

[pargyle]

I live in a 1930s house with a deep void under the wooden floor.
In order to prevent damp and wood rot , there are air bricks below floor level on all elevations , plus internal walls below floor level are built honey comb fashion to further assist ventilation. Over the years we have tried all sorts to reduce draughts during windy weather.to no avail.
Still conditions, it’s fine . Freezing winds suck the heat out of the house grand style .

My 1930’s semi is the same. I reckon my bees are warmer than me currently!

You need to get down into the void and fill the gaps between the joists with Celotex ... we did my Son's 1918 terraced house in Sheffield (Albeit the front of the house had a cellar, the back was just a deep void) some years ago ... Made a massive difference - need to pay attention to any gaps under the skirting boards as well - we packed those with strips of softboard as the draughts were coming up through there as well. Last bit was to put draught excluder around the cellar door !!

 

[oliver90owner]

It

It Does if the door is left open all winter

Please don’t be silly. The hive entranceis open all winter. The temperature at the floor level will be outside ambient.

As I said earlier, they do not need as much ventilation as provided by a full OMF. BUT bottom ventilation IS the secret to good over-winteting ((along wit good top insulation, of course).

How long will it be before all beekeepers realise this? Matchsticks under the cover board are dead. Minimum insulation above the colony is just plain stupid, for basically the same reason - heat retention. Some beekeepers seem to need to get real and forget the stupid practices recommended some of by the ‘dinosaurs’ in a certain Association.

 

[Patrick1]

Hi Patrick just to clarify, you monitor varroa via inspections, not sugar rolls or alcohol washes... One of my friends does this and I can see why.

Why put the bees through all that nonsense to achieve a number that someone has invented as being the economic threshold without any reference to the number of bees or more importantly the number of drones, do proper inspections, having run some advance beekeeping courses with a local NDB it is amazing how many beekeepers lift a frame out look at it an notice nothing, real inspections are so important.

 

[Poly Hive]

DAMP, CONDENSATION AND VENTILATION. Brood Rearing in the Winter Cluster. - Poly Hive Blog

Every beekeeper should read this.

PH

 

[jenkinsbrynmair]

why?

 

[Boston Bees]

why?

Because it helps his blog viewing numbers

 

[JamezF]

I'm probably stirring an asian hornet's nest here, but...

The open floor vs. closed/solid floor question is one I've struggled over myself for quite a few years without being able to convince myself that one should definitely be better than the other.

I've not seen a wild colony that chose to have its bum hanging out in cold air, but that might just mean that other aspects of the site were more compelling than whether it had too much or too little bottom ventilation. On the other hand, years ago I was taught that leaving the mesh floor open was good because falling varroa would drop through onto the ground and not be able to get back into the colony. But is it really true that any significant numbers of varroa fall off clustered bees in the winter without being able to grab onto another on the way down? Without further explanation I'm not really finding the idea convincing.

So, what are the verifiable pros and cons of each approach? I don't really want to pick on anyone in particular, but for example where oliver90owner says above "bottom ventilation IS the secret to good over-winteting (sic)" that's not really any more useful than what someone told me down the pub. Why, specifically, is bottom ventilation the secret to good over-wintering?

I'm not looking to put down one opinion or the other here, just to put myself in a better position to make a good judgement. And let's not worry about matchsticks in this instance. I have never been anywhere near any of my colonies with matchsticks.

James

 

[Curly green finger's]

I'm probably stirring an asian hornet's nest here, but...

The open floor vs. closed/solid floor question is one I've struggled over myself for quite a few years without being able to convince myself that one should definitely be better than the other.

I've not seen a wild colony that chose to have its bum hanging out in cold air, but that might just mean that other aspects of the site were more compelling than whether it had too much or too little bottom ventilation. On the other hand, years ago I was taught that leaving the mesh floor open was good because falling varroa would drop through onto the ground and not be able to get back into the colony. But is it really true that any significant numbers of varroa fall off clustered bees in the winter without being able to grab onto another on the way down? Without further explanation I'm not really finding the idea convincing.

So, what are the verifiable pros and cons of each approach? I don't really want to pick on anyone in particular, but for example where oliver90owner says above "bottom ventilation IS the secret to good over-winteting (sic)" that's not really any more useful than what someone told me down the pub. Why, specifically, is bottom ventilation the secret to good over-wintering?

I'm not looking to put down one opinion or the other here, just to put myself in a better position to make a good judgement. And let's not worry about matchsticks in this instance. I have never been anywhere near any of my colonies with matchsticks.

James

 

[Boston Bees]

So, what are the verifiable pros and cons of each approach? I don't really want to pick on anyone in particular, but for example where oliver90owner says above "bottom ventilation IS the secret to good over-winteting (sic)" that's not really any more useful than what someone told me down the pub. Why, specifically, is bottom ventilation the secret to good over-wintering?

Perhaps it would be better to say that top ventilation is the secret to bad overwintering (as it leads to a vertical draught flowing from the entrance, right up through the cluster, among other things)

Given that the hive needs some ventilation, that leaves the bottom (furthest from the cluster) as the place it should be. Leaving the top to be draught free and as warm as is possible (hence the addition of insulation in some cases).

But that isn't an argument for open mesh floors vs solid floors). It's an argument for not allowing any gaps at the top of the hive, and adding insulation up there.

Regarding mesh vs solid, I strongly suspect that it doesn't matter much. So don't worry about it. Certainly I can't believe that it makes a significant difference to varroa numbers.

 

[JamezF]

I don't blame you

I'm not attempting to change anyone else's mind here though. If someone wants to overwinter their bees on a bed of finest Camembert then they can knock themselves out. I'd just like to get a better understanding and to separate fact from hearsay so that I can make what I feel is the best decision for my own colonies.

James

 

[Erichalfbee]

I run both. There doesn’t seem to be much difference so far.
overwintering poly nucs are going to be on solid floors from next winter. Husband’s knocked up some solid UFE ones for me.

 

[jenkinsbrynmair]

I've not seen a wild colony that chose to have its bum hanging out in cold air

I have - one wild colony next to one of my apiaries in a near dead oak tree, a large hole at the base that you can get your head and shoulders in, the hole stretched up to a foot or so below the cluster, you can lie there and watch the bees work the comb.

 

[JamezF]

I have - one wild colony next to one of my apiaries in a near dead oak tree, a large hole at the base that you can get your head and shoulders in, the hole stretched up to a foot or so below the cluster, you can lie there and watch the bees work the comb.

Must be a fascinating thing to do. Not quite the same, but a few years back my daughter and I lay on the grass under some sycamore trees with swallows flying barely a foot from our faces picking off the aphids attracted to the leaves. It's amazing to be so close to "nature at work" without disturbing it.

I assume the top of the cavity was closed off so there was minimal updraught from the hole when not plugged by the head and shoulders of a beekeeper?

James

 

[Erichalfbee]

I have - one wild colony next to one of my apiaries in a near dead oak tree, a large hole at the base that you can get your head and shoulders in, the hole stretched up to a foot or so below the cluster, you can lie there and watch the bees work the comb.

And catch the varroa in your beard?

 

[jenkinsbrynmair]

I assume the top of the cavity was closed off so there was minimal updraught

No - the entrance hole is up near the top of the nest, hardly any bees flying out of the the base - unless there's a heavy flow on.

 

[Curly green finger's]

I don't blame you

I'm not attempting to change anyone else's mind here though. If someone wants to overwinter their bees on a bed of finest Camembert then they can knock themselves out. I'd just like to get a better understanding and to separate fact from hearsay so that I can make what I feel is the best decision for my own colonies.

James

Fact my poly nucs build up better when the floor is closed of in spring.
I have both solid floors and OMFs on my cedar single and double brood.
My hear say would be in my location( hills) solid floors would be better.
All my OMF floors have inspection boards in all winter. I say in, under resting on the pallets.
Give it a few more years and I'll have better results.