50% losses winter 2012/2013

[user 6228]

yep .. I've read all the stuff on warm way and cold way and I understand that bees could just move through the stores one way and then (when very cold) come up against the wall of the hive and be unable to find their way (or relocate) to where the stores were. But it appears to me that virtually everyone fed their bees with fondant above the frames last winter - expecting the worst as the year before - and yet still colonies died out. It has to be more complex than Isolation Starvation - although it is, clearly, one factor.

When you have insulated the sides and top with a continous air tight insulation to at least 2" of kingspan down to entrance level ,then you may have eliminated thermal losses as a factor.

 

[pargyle]

When you have insulated the sides and top with a continous air tight insulation to at least the equivalent of 3" of polystryrene or 2" of kingspan down to entrance level ,then you will have eliminated thermal losses as a factor.

That's what I'm hoping ! I've just ordered the temp and humidity recorder from fleabay ... retrofitting it on the hive and then I'm going to start monitoring.

 

[Skyhook]

When I found out that the association apiary is nearby I thought..."goody at least we can synchronise autumn treatment". The strongest hive that was to be "Snelgroved" the following week to demonstrate the method to students had obvious severe DWV. A shiny plastic inspection board with no sticky was put in for a count. I asked what they used for their autumn treatment and was told Hive Alive.
How do you,as a newbee, speak up without ruffling old feathers?

I didn't know hive alive, so just looked it up assuming it to be like hiveclean. It doesn't even claim to control varroa! I think you may have to speak up. Maybe in question form- 'oh that's interesting, I thought that was just for nosema- how do they recommend using it against varroa?'

 

[pargyle]

I didn't know hive alive, so just looked it up assuming it to be like hiveclean. It doesn't even claim to control varroa! I think you may have to speak up. Maybe in question form- 'oh that's interesting, I thought that was just for nosema- how do they recommend using it against varroa?'

Of you go to the Th***S website it states on there that hive alive is just about the pancea for everything except beekeepers back ! And it's just made from ... Grass ?

http://www.thorne.co.uk/index.php?route=product/product&product_id=5293

 

[itma]

When I found out that the association apiary is nearby I thought..."goody at least we can synchronise autumn treatment". The strongest hive that was to be "Snelgroved" the following week to demonstrate the method to students had obvious severe DWV. A shiny plastic inspection board with no sticky was put in for a count. I asked what they used for their autumn treatment and was told Hive Alive.
How do you,as a newbee, speak up without ruffling old feathers?

You ask how their trial of MAQS went.

 

[Lorenz]

I have had more Nosema this year than normal. I lost one colony that was a DLQ, but all the nucs survived. I always give thymol in the Autumn syrup, to help against Nosema, but I think some people did nothing last year, with Fumidil not being an easy option any more.

Anyone else noticed Nosema this year? I think that it has to be in the frame.

 

[DanBee]

yep .. I've read all the stuff on warm way and cold way and I understand that bees could just move through the stores one way and then (when very cold) come up against the wall of the hive and be unable to find their way (or relocate) to where the stores were. But it appears to me that virtually everyone fed their bees with fondant above the frames last winter - expecting the worst as the year before - and yet still colonies died out. It has to be more complex than Isolation Starvation - although it is, clearly, one factor.

I think you've still missed the point. Isolation starvation occurs when the cluster is too small compared with the outside temperature to move to where the food is. Susbees hinted at this above - the energy required to move around to get to the source of energy. It has very little to do with which direction they need to go - sideways or up - and much more to do with how far from where they are now.

I was going to write a caveat to say that the issue of isolation starvation isn't related to comb orientation - slices of a sphere, they're going to have ends whichever way you slice it. So isolation is not a warm/cold way disorder.

Yes changing the materials for more or less inherent insulation will adjust the relationship between cluster size and survivable outside temperature, but only in so much as it adjusts the critical point in the relationship.

Do we know if clustering is good for a colony? Winter bees are raised to survive the winter, and they do this by a combination of body reserves and inactivity. They certainly seem to have adapted to a need to cluster over winter, given that this was not a feature in their original geography. What behavioural and physiological changes would occur in an over-wintering colony that was so toasty it didn't need to cluster? How much stores would they need? I assume that if they're doing more (metabolically) they'll need to take cleansing flights more often... and if it's still sub-zero outdoors, what happens then?

More to this than warmer=better. And I don't mean pesticides...

 

[pargyle]

I think you've still missed the point. Isolation starvation occurs when the cluster is too small compared with the outside temperature to move to where the food is. Susbees hinted at this above - the energy required to move around to get to the source of energy. It has very little to do with which direction they need to go - sideways or up - and much more to do with how far from where they are now.

I was going to write a caveat to say that the issue of isolation starvation isn't related to comb orientation - slices of a sphere, they're going to have ends whichever way you slice it. So isolation is not a warm/cold way disorder.

Yes changing the materials for more or less inherent insulation will adjust the relationship between cluster size and survivable outside temperature, but only in so much as it adjusts the critical point in the relationship.

Do we know if clustering is good for a colony? Winter bees are raised to survive the winter, and they do this by a combination of body reserves and inactivity. They certainly seem to have adapted to a need to cluster over winter, given that this was not a feature in their original geography. What behavioural and physiological changes would occur in an over-wintering colony that was so toasty it didn't need to cluster? How much stores would they need? I assume that if they're doing more (metabolically) they'll need to take cleansing flights more often... and if it's still sub-zero outdoors, what happens then?

More to this than warmer=better. And I don't mean pesticides...

Yes ..., I didn't completely miss the point. I can see the logic, thanks for the fuller explanation - DC (and others) don't make it quite as clear as this. I agree fully that there is more to it than warmer/better and I think its a very complex set of circumstances that lead to isolation starvation. It still doesn't explain, however, why colonies would ignore fondant placed immediately above them on the frames and accessible as a food source ? I understand that the colony forms a ball, usually in the middle of the frames but extending upwards so why would they not be able to access food stored above them. The significant heat of a colony can be felt immediately above them on the crown board (even at this time of the year !) so one would have thought that the top of the ball would remain mobile simply because it must be warmer than the sides or bottom ?

Do small colonies cluster in the centre of the frames or do they move upwards in the hive to just under the top bars ? This must surely be the warmest section of the brood box and the area which one would suppose is the best place for them

I haven't mentioned pesticides as I don't want this thread descending into the normal fracas ... if we leave any such influences out of the equation you are only left with colony size, heat, humidity, feed, disease and parasitic effects. So, what is the combination of hive structure/insulation/husbandry that is going to ensure that MY colony survives next winter ?

 

[user 6228]

Yes ..., I didn't completely miss the point. I can see the logic, thanks for the fuller explanation - DC (and others) don't make it quite as clear as this. I agree fully that there is more to it than warmer/better and I think its a very complex set of circumstances that lead to isolation starvation. It still doesn't explain, however, why colonies would ignore fondant placed immediately above them on the frames and accessible as a food source ? I understand that the colony forms a ball, usually in the middle of the frames but extending upwards so why would they not be able to access food stored above them. The significant heat of a colony can be felt immediately above them on the crown board (even at this time of the year !) so one would have thought that the top of the ball would remain mobile simply because it must be warmer than the sides or bottom ?

Do small colonies cluster in the centre of the frames or do they move upwards in the hive to just under the top bars ? This must surely be the warmest section of the brood box and the area which one would suppose is the best place for them

I haven't mentioned pesticides as I don't want this thread descending into the normal fracas ... if we leave any such influences out of the equation you are only left with colony size, heat, humidity, feed, disease and parasitic effects. So, what is the combination of hive structure/insulation/husbandry that is going to ensure that MY colony survives next winter ?

do they have an adequate reserve of water to make use of the fondant/honey?

 

[pargyle]

do they have an adequate reserve of water to make use of the fondant/honey?

Now that's an interesting point ... I understand that bees, during periods when the can't fly, utilise any condensation within the hive as their water source. So, it's yet another potential factor that could contribute to the reason why colonies with fondant in the hive over winter cannot make use of it.

So, are we saying that a rapid feeder with a high strength solution in the hive over winter (but with insulation above it) might be a better option than fondant in a hive where there is likely to be cold temperatures and little condensation ?

 

[pargyle]

From Norton:

http://www.beekeepingforum.co.uk/showthread.php?t=24187

 

[clv101]

I'm fairly satisfied with the explanation that the heavy winter losses are predominately explained by weather. It was an awful summer followed by awful spring. If, due to climate change and particularly the loss of Arctic ice having a permanent impact on the jet stream making last summer the 'new normal', I expect beeks will have to adjust their husbandry techniques in ways that aren't yet clear and we may have to adjust the stock of bees kept in the UK.

Bees face lots of compounding challenges, but in my humble experience it was the weather what done it this time.

 

[DanBee]

Derek made the point I would make: the need for water to consume fondant. I don't have the figures but recall that fondant is 5-10% water. Unlike honey, which absorbs moisture from the air (self-diluting from some of that respiratory water vapour, if you will), fondant has a tendency to dry and harden when exposed.

So for a colony on the very edge of survival, uncapping liquid honey would be the lifeline; finding granulated honey under the cappings or having fondant dry out would probably tip them over the edge. This is why the beekeeper remedy upon finding such a situation is to spray 1:1 syrup over the starving bees - immediate metabolism with minimal processing.

As regards the mechanics of isolation starvation, I took this photo of one poor colony found in March as it was pretty much "textbook" in appearance. It still hurts when you see this, however many colonies you have. In many ways you feel more responsible with more experience You can see they just "painted themselves into the corner", given that the cluster would likely have started in the dark well-brooded area of the comb in autumn.

 

[Roger]

Now that's an interesting point ... I understand that bees, during periods when the can't fly, utilise any condensation within the hive as their water source. So, it's yet another potential factor that could contribute to the reason why colonies with fondant in the hive over winter cannot make use of it.

So, are we saying that a rapid feeder with a high strength solution in the hive over winter (but with insulation above it) might be a better option than fondant in a hive where there is likely to be cold temperatures and little condensation ?

I have in the past left a rapid feeder on a few hives over winter as I felt they had not taken down enough stores. The bees did not touch it.

Roger

 

[MuswellMetro]

Anecdotally the analysis of about 50+ hives from around my association

losses 5% on 20 14x12/commercials hives with 2" kingspan of more roof insulation varroa board out
losses 10% on 10 14x12 hives with loose poly bead cushion insulation in super
losses 33% on 9 14x12 hives with £hornes thin quilt varroa board out
losses 100% on 11 14x12 hives with open feed holes, varroa board in
losses 80% on 10 14x8 hives ,matchsticks and solid floors
losses zero on 2 14x12 POLYHIVES, and had 4 frames of stores in march
Looses 95% in 20 over winter nucs no insulation
losses zero on 3 overwinter Nuc insulated 2" kingspan on roofs

not included above are my own losses which were zero on both 14x12 and Nucs all with 2" minimum roof insulation,varroa board out, empty super under floor though had one drone layer on a hive that started building up then the queen failed in May, feedbee pollen sub in Feb, fondant in March due to bad weather[some are 3 floors up on North facing roofs]

I will contiinue to follow B Mobus 1984 articules and Dave Cushman rather than Wedmores 1947 top ventilation approach

 

[pargyle]

Derek made the point I would make: the need for water to consume fondant. ....

As regards the mechanics of isolation starvation, I took this photo of one poor colony found in March as it was pretty much "textbook" in appearance. It still hurts when you see this, however many colonies you have. In many ways you feel more responsible with more experience You can see they just "painted themselves into the corner", given that the cluster would likely have started in the dark well-brooded area of the comb in autumn.

That's tragic isn't it ? So near and so much left.

It looks to me as though the key to overwintering successfully, in our changing weather, is lots of insulation but particularly on the top of the hive, no top ventilation at all. I have bottom ventilation that I can adjust and I can seal the OMF if I wish so if some bottom ventilation is desirable then that is possible. Perhaps additional winter feeding with the option of fondant and a rapid feeder is an option so that the bees can choose. A fondant pad enclosed in a slitted poly bag but with a central hole made in the fondant so that they could access a rapid feeder through it might be an experiment worth trying. But insulate the space around and above the rapid feeder so there is no uneccessary heat loss ?

I recognise that those of you with lots of hives are not going to want to mess about to this extent but for those of us with one or two we can spend a bit of energy to protect the colonies we have. It looks from all the stats so far that poly has a much much higher chance of overwintering and perhaps we will all end up here eventually ? Whatever shape that may be in ...

 

[sunhivebee]

Danbee : ".... Isolation starvation occurs when the cluster is too small compared with the outside temperature to move to where the food is. Susbees hinted at this above - the energy required to move around to get to the source of energy. It has very little to do with which direction they need to go - sideways or up - and much more to do with how far from where they are now.

I was going to write a caveat to say that the issue of isolation starvation isn't related to comb orientation - slices of a sphere, they're going to have ends whichever way you slice it. So isolation is not a warm/cold way disorder.

Yes changing the materials for more or less inherent insulation will adjust the relationship between cluster size and survivable outside temperature, but only in so much as it adjusts the critical point in the relationship.

Do we know if clustering is good for a colony? Winter bees are raised to survive the winter, and they do this by a combination of body reserves and inactivity. They certainly seem to have adapted to a need to cluster over winter, given that this was not a feature in their original geography. What behavioural and physiological changes would occur in an over-wintering colony that was so toasty it didn't need to cluster? How much stores would they need? I assume that if they're doing more (metabolically) they'll need to take cleansing flights more often... and if it's still sub-zero outdoors, what happens then? ..... "

Brilliant post, i.m.h.o., and essential reading for beginners.
Isolation starvation, of all the disasters which can befall a colony, is avoidable if colonies are helped to go into winter in the right configuration, as detailed by some of the posts above. Insight into colony life certainly helps to establish the "right configuration" - whether in wood, poly or straw ....

 

[PBee]

........
Do we know if clustering is good for a colony? Winter bees are raised to survive the winter, and they do this by a combination of body reserves and inactivity. They certainly seem to have adapted to a need to cluster over winter, given that this was not a feature in their original geography. What behavioural and physiological changes would occur in an over-wintering colony that was so toasty it didn't need to cluster? How much stores would they need? I assume that if they're doing more (metabolically) they'll need to take cleansing flights more often... and if it's still sub-zero outdoors, what happens then?
........

The metabolic rate decreases with rise in temperature so less cleansing flights should be needed.

Southwick (1983, 1988) and Southwick and Heldmaier (1987) showed that the oxygen consumption of winter clusters increases as the ambient temperature decreases. The increase is moderate between approximately +10°C and -5°C and is steep below approximately -5°C to -10°C. In swarm clusters, the steep increase has already started at +10°C (Heinrich, 1981). Oxygen consumption also increases with decreasing cluster size (Southwick, 1985). Therefore, the frequency and intensity of endothermic heat production have to be assumed to increase with decreasing ambient temperature and cluster size. On the other hand, we suggest that at higher ambient temperatures large (swarm) clusters that have come to rest (e.g. at night) may be able to largely reduce endothermy (Heinrich, 1981).

http://jeb.biologists.org/content/206/2/353.full

My (fairly recent) experience wintering with polyhives on solid poly floors and restricted ventilation is that the colony clusters less densely and hives are remarkably dry. I also had some colonies last winter in Nicot plastic hives with plastic OMF and poorly sealed varroa trays. These had tight clusters and had quite a bit of condensation inside. Survival was identical in both and normal. Late winter cluster ....

 

[Erichalfbee]

My (fairly recent) experience wintering with polyhives on solid poly floors and restricted ventilation is that the colony clusters less densely and hives are remarkably dry. I also had some colonies last winter in Nicot plastic hives with plastic OMF and poorly sealed varroa trays. These had tight clusters and had quite a bit of condensation inside. Survival was identical in both and normal.

I'd be really interested to hear more, PBee

 

[Fraise]

MuswellMetro's numbers are interesting but some are meaningless without knowing what type of varroa boards were used.

There are 2 designs of varroa board, one with an upstand which effectively seals the bottom of the hive and the other which is a simple sheet of correx or ply. The latter leaves a half inch ventilation gap across the width of the back of the hive.
If the hive is fitted with an entrance block or mouse guard then any wind blowing directly onto the back will be forced up through the hive because the entry area is bigger than the available exit.
Many hives face south so the problem winds will tend to be the colder ones from the north.