Poorly bees- CBPV?

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Skyhook

Queen Bee
Joined
May 19, 2010
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Location
Dorset
Hive Type
14x12
Number of Hives
5
My bee shave always been healthy as long as I've kept on top of varroa. Last year I had 2 colonies dwindling and couldn't work out why. I got the inspector to check them and he didn't know, but confirmed that it wasn't foul brood. I combined the 2 (as they were in the same condition) then killed them off when they were clearly still going downhill. I now have another hive going the same way, and none of the others are thriving.

I've seen virus symptoms- shiny bees and separated wings- but didn't think that was pointing towards the primary cause. There are now lots of dead bees outside the hives, and bees crawling on the landing boards.

I had 3 main suspects- varroasis, nosema or, as a long shot, acarine. I'm almost ruling out nosema as there has been no dysentry, and no improvement with the arrival of summer. Acarine seems very rare these days; and the bees were treated with thymol at the end of last summer, and trickled with OA in January.

More reading seems to be pointing me at CBPV- and depressing reading it is too.

Is there any certain way of diagnosing it?

What are my chances of saving them? I've seen the post about shaking them out, but I'm not sure if that is only for light infestations.

Is there anyone who can carry out microscopy for Acarine and Nosema- even if only for elimination purposes? The national bee unit has stopped doing it. I know Bcrazy offered to test samples, but that was some time ago.

I'm starting to think my bees are on the way out- any light that anyone can shed would be very welcome.

Skyhook
 
A couple of mine had this last year... cbpv is most probably in all colonies but often has no marked effect. It seems to take hold more if bees are kept in by poor weather and are cramped. Shiny bees are usually ejected from the colony or refused entrance on returning. I have had huge piles of bees out the front of the hive from a serious outbreak and it can be quite ditressing... but there is no treatment really, it's a hope for the best scenario. If the weather improves then the hives will be less cramped and as such transmission rates might be lower. It might also be worth checking varroa loads as there are two schools of thought for transmission. It could be to do with bodies in close proximity rubbing away hair folacles and allowing entrance of the virus, others believe varroa might act as a vector. Requeening is one other possible route as genetics may play a part in resilience to the virus... but that depends on the stare of the colony and whether you have a spare queen.
 
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I had 3 main suspects- varroasis, nosema or, as a long shot, acarine. I'm almost ruling out nosema as there has been no dysentry, and no improvement with the arrival of summer. Acarine seems very rare these days; and the bees were treated with thymol at the end of last summer, and trickled with OA in January.

More reading seems to be pointing me at CBPV- and depressing reading it is too.

Don't rule out Nosema ceranae, it's almost symptomless except that the bees fail to thrive, but it can be seen in a microscope. Has your association got any microscopes?

OA trickling in January was probably a waste of time because it was too warm, and colonies would probably have had a decent amount of brood.

As far as I can remember CBPV is transmitted more readily when the bees are overcrowded, which can happen when it's too cold for them to fly. It's been too blimmin cold recently here, so I'm guessing it's probably the same over your way. One or two fine days won't be enough to clear the colony of damaged bees.

ChrisfNVS has good experience of dealing with CBPV, it might be worth sending him a personal message? http://www.beekeepingforum.co.uk/member.php?u=6770 Failing that why not contact your SBI?
 
Don't rule out Nosema ceranae, it's almost symptomless except that the bees fail to thrive, but it can be seen in a microscope. Has your association got any microscopes?

OA trickling in January was probably a waste of time because it was too warm, and colonies would probably have had a decent amount of brood.

As far as I can remember CBPV is transmitted more readily when the bees are overcrowded, which can happen when it's too cold for them to fly. It's been too blimmin cold recently here, so I'm guessing it's probably the same over your way. One or two fine days won't be enough to clear the colony of damaged bees.

ChrisfNVS has good experience of dealing with CBPV, it might be worth sending him a personal message? http://www.beekeepingforum.co.uk/member.php?u=6770 Failing that why not contact your SBI?

From the original post. " I got the inspector to check them "
Also the thread about spray poisoning which turned out to be CBPV described the shaking out process. It's traumatic for the colony and not something to play at unless you are sure of what you are dealing with.
From hearing nothing about practical incidents of CBPV until this year it seems to be suddenly moving into the beekeepers arena. This may mean that previous problems attributed to spray poisoning were misdiagnosed and it's been missed through unfamiliarity, or it's going to become a straw to grasp at when the beekeeper is baffled. It needs careful thought!

Reference the Nosema and microscopy, it's perfectly possible to get hold of cheap no frills microscopes for not much money. I bought a high end toy model at a car boot sale for less than ten pounds. It gives 100, 400 and 600x magnification. A box of slides and covers costs more than the microscope :(
 
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I've had one colony that definitely succumbed to CBPV .. basically dwindled to nothing. I have 4 other colonies that have been struggling .. I I've attempted to requeen once but to no avail (need to try again this weekend), and the other 3 are either limping along or now starting to recover. Once has been on 1.5 super frames of brood for the last 6 weeks, one on 3 frames, and the other has now reached the giddy heights of 5 frames.
All this with other colonies on 8+8, with capped supers, and in one case it's the hive next door, or requiring splitting due to wanting to swarm.
It's been a strange year so far..
 
Thanks for the responses guys. I'll try getting hold of ChrisfNVS, see how he deals with it. I do have a small microscope which allegedly goes up to x 900- you just can't see anything at the higher magnifications, I was assuming it would need a better quality scope- if there's no-one that does it, I might have to try ebay.

With the end of the government service, I'm amazed no-one has set up a little business doing testing!
 
Thanks for the responses guys. I'll try getting hold of ChrisfNVS, see how he deals with it. I do have a small microscope which allegedly goes up to x 900- you just can't see anything at the higher magnifications, I was assuming it would need a better quality scope- if there's no-one that does it, I might have to try ebay.

With the end of the government service, I'm amazed no-one has set up a little business doing testing!

Hi
My understanding is that x400 magnification is required for nosema observation.
 
If it's CBPV the only thing you can do is add space and shake them out, the unaffected bees will make their way back the sick ones won't.
Your SBI should have advised you of this.
Fast action is the only way to save the colony.
 
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