Nosema treatment nessecary?

after a couple of weeks I decided to go and check on my bee hives and feed the light colony some fondant and put a home made perspex cover on before I leave on holidays. despite the dark, they came boiling out as soon as I started to remove the woodpecker protection. it was mild yesterday night, around 12C but I did not expect them to be so feisty. treated to 2 stings only...

worryingly, the grass in front of both hives was full of moribund and dead bees. As this is my first year of beekeeping, I have no idea what a normal winter die off looks like but this seems a bit excessive. I am talking between 100 to 200 bees per hive here. I treated with thymolated syrup as a measure against nosema in september. Is there anything that can/should be done now against this mid winter to ensure I have a colony left to requeen in spring?

Ps: Nessecary = Necessary

Relax.
Trim the grass if it is long.
If you can, ensure that they have a safe, shallow, sun-warmed water source that they can locate easily.


Water foraging (including from rain and dew on grass) in cool weather is one of the most dangerous activities for the bees. They get chilled and can't fly, so they die. Making it easier and safer makes for fewer bees dying in the effort to get water.
One reason for needing water is to deal with crystallised stores.
Once the weather is properly cold, there should be some condensation on the coldest part of the hive, which allows the bees to (fairly) safely recycle that water. (Condensation in the right place is a benefit, not a problem.) Until then, its a matter of them collecting up rainwater, which is hazardous for the foragers.


Don't assume "dead bees seen => nosema => must treat".
Nosema spores are viable (therefore detectable for sure) for at least six months.
Weren't you going to do some microscopy to investigate? (And I'd again point you towards Randy Oliver's "Quick Squash Method" for indicating the extent of whatever Nosema problem.)
Those dead bees on the grass could be tested for Nosema … though I'd expect that was unlikely to have contributed significantly to the death toll.

thenovice said:

after a couple of weeks I decided to go and check on my bee hives and feed the light colony some fondant and put a home made perspex cover on before I leave on holidays. despite the dark, they came boiling out as soon as I started to remove the woodpecker protection. it was mild yesterday night, around 12C but I did not expect them to be so feisty. treated to 2 stings only...
worryingly, the grass in front of both hives was full of moribund and dead bees. As this is my first year of beekeeping, I have no idea what a normal winter die off looks like but this seems a bit excessive. I am talking between 100 to 200 bees per hive here. I treated with thymolated syrup as a measure against nosema in september. Is there anything that can/should be done now against this mid winter to ensure I have a colony left to requeen in spring?
Ps: Nessecary = Necessary

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Yes, one can't help worrying! I posted a thread 'Checking for dead bees on the OMF' on 13 November (sorry, I don't know how to add the link). Briefly, I had fed all 9 colonies with thymolated syrup but mid Nov found 2 hives had copious dead bees on the OMF. Microscopy showed Nosema++. Today ( Temp 12C) both hives had even more dead bees - horrible job sweeping them out with hook end of a long hive tool. Very few live bees emerged (compared with enraged bees +++ from the other 7 colonies - I do a sweep monthly). I did see a few live bees thro' the crown boards. I assumed the colonies were dead or dying but nevertheless treated with sublimated oxalic acid via a Varrox. Happily in both cases there was a loud roar of agitated bees. So, while there's life there's hope. The other hives had very few dead bees including one I had treated with OxA.

Novice,
They try and remove 'naturally dead' from inside the hive; in the Summer you see them flying off with the bodies but in this colder darker weather maybe chucking them off the landing board is the preferred option.

Dead bees on the hive floor is a bigger worry....

richardbees said:

Novice,
Dead bees on the hive floor is a bigger worry....

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Hi Richard et al,
I have dead bees on the OMF every spring. Isn't that why it is prudent to change the floor when we spring clean?
Two hives, which are positioned against south facing brick wall today had their spring cleansing flights making a right mess of the hives. Will clean them with 1:5 bleach solution tomorrow. This is what usually happens March/April, but it is 15C here today and they are on Ivy this year, so they will have consumed more roughage than from sugar syrup. Maybe all the flying the day before was water collection. They seem lively enough, so I am not worried. Most bees in the UK are carriers of nosema and CPBV which comes out when the bees are under stress.

beeno said:

…
Two hives, which are positioned against south facing brick wall today had their spring cleansing flights making a right mess of the hives. Will clean them with 1:5 bleach solution tomorrow. This is what usually happens March/April, but it is 15C here today and they are on Ivy this year, so they will have consumed more roughage than from sugar syrup. Maybe all the flying the day before was water collection. They seem lively enough, so I am not worried. Most bees in the UK are carriers of nosema and CPBV which comes out when the bees are under stress.

Click to expand...

Hmmm.
**** splattering of the front of the hive and landing board (even in Spring) is a cause for concern.
On a mild day in December, I'd say more so.

Typically Nosema apis (the traditional UK one) flares up over Winter (with the bees confined) and tends to disappear as the weather gets properly warm.
And **** splattering particularly inside the hive (if its there its going to be on the hive front as well) is the classic sign of Nosema apis - rather than just dead bees.
When you open up for Oxalic trickling, beeshit on the frame topbars is one of the things to just keep an eye open for.

On the other hand, the new one, Nosema ceranae (from the same bees that gave us varroa), is more of a year-round disease and does not seem to be associated with **** splattering, just a weak colony.



Personally, I'd be more concerned about **** splattering than seeing dead bees on the grass …
Nosema apis is spread through bee ****, and gives bees the runs, spreading it with a 'snowball' effect (another dirty snowball).
So avoiding bees getting tummy upsets is the basic control (in case they are carrying Nosema), which is why we don't feed syrup too late in the season.

thanks for all the replies! I tried to get a sample of bees from the entrance in september but did not master the right commands. they would simply not go into my container . I should have collected some bees now for testing but had no container with me and was eager to get out of the rain... the road to heaven is paved with good intentions. if only my apiary was in my back garden and time was a commodity bought in Asda...

I have my reservations with the water foraging idea of Itma. I see this happening in cold weather but on the day it had been very mild with light drizzle. Even at 9pm it was still above 10C so they should have been able to get water from the landing board or if they were going out, it should have been warm enough for them to make it back.

As for relaxing. I am totally relaxed about it hence the post. if I was panicking I would have sprayed them with thymol or something. Just wanted to hear the community out and it seems that doing nothing and provide some water source is the best option for now...

thenovice said:

... Even at 9pm it was still above 10C so they should have been able to get water from the landing board or if they were going out, it should have been warm enough for them to make it back.
...

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The bees problem is keeping their thoracic flight muscles above 25C …
Taking onboard water at even 10C has a significant chilling effect.

itma said:

The bees problem is keeping their thoracic flight muscles above 25C …
Taking onboard water at even 10C has a significant chilling effect.

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Maybe you are right. but in this case, what can I do about it? even having a water source in a black container or other heat source would not make the drizzle any warmer... feeding them water at the entrance? not practical for me and with mouse guards not that easy.

itma said:

Hmmm.
**** splattering of the front of the hive and landing board (even in Spring) is a cause for concern.
On a mild day in December, I'd say more so.

Typically Nosema apis (the traditional UK one) flares up over Winter (with the bees confined) and tends to disappear as the weather gets properly warm.
And **** splattering particularly inside the hive (if its there its going to be on the hive front as well) is the classic sign of Nosema apis - rather than just dead bees.
When you open up for Oxalic trickling, beeshit on the frame topbars is one of the things to just keep an eye open for.

On the other hand, the new one, Nosema ceranae (from the same bees that gave us varroa), is more of a year-round disease and does not seem to be associated with **** splattering, just a weak colony.



Personally, I'd be more concerned about **** splattering than seeing dead bees on the grass …
Nosema apis is spread through bee ****, and gives bees the runs, spreading it with a 'snowball' effect (another dirty snowball).
So avoiding bees getting tummy upsets is the basic control (in case they are carrying Nosema), which is why we don't feed syrup too late in the season.

Click to expand...

Hi itma, Thank you for your contribution as always. Cleaned the two hives this morning and they are still clean now. It has been a lovely day sunny and warm, but getting chillier by the minute now.
I did not find any mess on top bars on any of my hives or nucs, when I applied OA. Perhaps yesterday was a 'lets-all-do-it-day'. Looked like the aftermath of normal spring cleansing flights to me, the surprise being that it is December. However, weather is more like April and first year on Ivy for my bees may have something to do with it.
I would not say that my bees have been confined this winter. I certainly did not feed syrup late in the season and in actual fact I have hardly fed any at all - no need this season.
My polyhive did not have any bees flying this morning which was a bit of a shock initially, but they are often the last lot out in winter. Sorry, but I gave them a knock and got a huge 'fizzzz' back, so all is well.

"I tried to get a sample of bees from the entrance"

The simplest method is to block the entrance at a time when they're v active - within minutes you'll have 'beards' of bees around the entrance which are easy to scoop into a plastic bag.