A way to combat CBPV?

[jenkinsbrynmair]

David Evans says there is no link between tracheal mite and CBPV

Yes, been known for a while, that's why @Apiarist 's statement on tracheal mites (and the fact that varroa treatment kills them!?) totally confused me

 

[Erichalfbee]

Yes, been known for a while, that's why @Apiarist 's statement on tracheal mites (and the fact that varroa treatment kills them!?) totally confused me

Well I simply wanted to post a “ reliable source”

 

[jenkinsbrynmair]

Well I simply wanted to post a “ reliable source”

Glad you did as I thought maybe I'd missed a trick somewhere

 

[Wilco]

Given wasp season is rapidly approaching, would a potential modification of this method work: rather than simply having an open floor which wasps may at some point fly up into, could the box being used to create the long drop be fitted with two steeply set boards forming a V shape (open at the bottom of the V)? This would narrow the gap significantly so make it easier to defend but maintain the dead bees being dropped out under gravity.

 

[bobba]

I have had CBPV in low levels in my hives for the 2 years I have been keeping bees. Its usually just about this time of year I will start to see the odd suffering bee dying on the lawn, and maybe see some on inspection. If my bees were not in my garden I would probably never have noticed the ones on the ground.

As soon as the supers are off, I treat for mites (I always seem to have a lot of mites) and the problem seems to go away. I dont know if the mite treatment helps or if the bees just forage less and I stop inspections so just dont notice it. But either way by spring its gone, then slowley builds up again.

I dont blieve anyone has proven that mites can transfer CBPV, but I have a hunch that they act as a stress factor on the hive making spread more likely

I know it gos without saying, but if you have a bad CBPV problem then you should check mite load and treat if necessary.

I have read everything I can find to try to understand CBPV to help protect my bees. And from my understanding the advice JBM has provided is very good and is exactly what I would do if I observed spread getting out of control.

Given wasp season is rapidly approaching, would a potential modification of this method work: rather than simply having an open floor which wasps may at some point fly up into, could the box being used to create the long drop be fitted with two steeply set boards forming a V shape (open at the bottom of the V)? This would narrow the gap significantly so make it easier to defend but maintain the dead bees being dropped out under gravity.

It would help with the wasp situation. But I would be concerned it may collect more poo and hairs than a mesh floor.

I know this is a drastic solution, but I have a 2.5m tall netting screen 1m away from my hives. I have this as bees are in my garden, so this makes them fly up and away. But the wasps hate to enter the mesh area. The wasps dont seem to be as good at steep accents as bees, so struggle to fly out and bash their heads repeatedly. They usually drop anything they are trying to carry too.

I have also observed a CBPV infested bee struggling to fly over the netting, bash its head and end up on the lawn. I had a short nosema outbreak once too, I could see poo streaks on the netting, but I also saw loads of bees dyeing on the outside of the netting because they could not find their way home, and thankfully it cleared up after about a week. So I am convinced the netting can also help stop sick bees getting home in addition to offering some wasp protection.

I know its a lot of hassle to put up such a netting screen. But if you have a dedicated isolation apiary, I recommend giving it a try. I truly think it will offer some wasp and disease protection. Its certainly not a magic cure all method, but I think it gives them a little helping hand.

I use that green scaffolding netting if anyone is interested.

 

[Apiarist]

David Evans says there is no link between tracheal mite and CBPV

Hi Erichalfbee and jenkinsbrynmair

thanks for the Link to "CBPV as a serious emerging threat to honey bees", I had already read it with interest.

A quick glance at "Honey bee pathology" (Bailey et al.) confirms that the virus can be spread by injecting, feeding or spraying the bees with it, this is what jenkinsbrynmair has described already, as a possible means of the virus spreading inside the hive once it has become established within the hive. It is noted that infection through injection is most effective, (at least 10000 times more effective), and that Acarapis woodi pierce the tracheal walls with their mouth parts to feed on the haemolymph...

Here's a direct quote (brackets and emphasis added for clarification), "investigations of sick colonies found severely infested in summer with (Acarapis woodi) mites showed that, whereas both sick and apparently healthy bees from the colonies were infested about equally with A. woodi the sick bees only were all infected with chronic paralysis virus (CBPV)", that means that it was ONLY the Acarapis woodi mite infested bees that had CPBV. Now I know what you are about to say, correlation is not causation, you're right, and in the spirit of full disclosure (and to argue against my own arguement...)

Bailey's opinion of a relationship was, "(Acarapis woodi) parasite is also widespread and enzootic (endemic), but is independent of paralysis (CBPV)"

I had thought that it was accepted that there was a co-existence between these mites and this virus, (not a cause and effect, like varroa and DWV) it appears I was wrong. And this interesting observation made by Bailey has been dismissed.

HOWEVER, some years ago when I had just started out beekeeping, I was in the No Treatment camp, at the end of the second year my dozen hives all had large numbers of flightless bees with K wings, all symptoms of CBPV, not to mention a lot of Varroa (but surprisingly not that much DWV). I had read about Acarine, etc. etc. and believed bees only had CBPV with Acarapis mites, so I treated for Varroa (I read it would affect A. woodi as well) and in about 10 to 14 days, the flightless bees and the K wings were virtually gone.

All I'm saying, whenever I saw what I believed to be CBPV, I treated as if for Varroa, to kill of the Acarapis woodi mite to get rid of CBPV, it worked for me, but I could have got lucky...

Hope I haven't caused confusion / annoyance, etc. I'm just adding to a discussion, with my opinions / observations

 

[peteinwilts]

I have had an issue for a few years.
Once it was in an apiary, it was difficult to get out.
Tried the vertical shook swarm method early on. It seemed to help, but the same bees would suffer the following year.
I quarenteened the affected apiaries and tested different treatments. I tried varroa treatments including formic, oxalic and thymol treatments. Results were mixed, and even where it appeared to clear up, it was back the following year. It is not impossible a hive that was clear became reinfected by a hive that had a treatment that didn't work. Testing treatments is for the long haul.
I had a fair number of losses over the extended winter, but included all of the weaker bees that had suffered with cbpv. So far, this year I have seen no cases.
If I do, I will certainly try the open floor method.

Great thread, and is really good to share theories and experiences.

 

[Erichalfbee]

It’s strange isn’t it. I had a big colony come down with it last year just after I split the queen off for swarm control. The big hive died the queen survived and is thriving this year

 

[bobba]

Hi Erichalfbee and jenkinsbrynmair

thanks for the Link to "CBPV as a serious emerging threat to honey bees", I had already read it with interest.

A quick glance at "Honey bee pathology" (Bailey et al.) confirms that the virus can be spread by injecting, feeding or spraying the bees with it, this is what jenkinsbrynmair has described already, as a possible means of the virus spreading inside the hive once it has become established within the hive. It is noted that infection through injection is most effective, (at least 10000 times more effective), and that Acarapis woodi pierce the tracheal walls with their mouth parts to feed on the haemolymph...

Here's a direct quote (brackets and emphasis added for clarification), "investigations of sick colonies found severely infested in summer with (Acarapis woodi) mites showed that, whereas both sick and apparently healthy bees from the colonies were infested about equally with A. woodi the sick bees only were all infected with chronic paralysis virus (CBPV)", that means that it was ONLY the Acarapis woodi mite infested bees that had CPBV. Now I know what you are about to say, correlation is not causation, you're right, and in the spirit of full disclosure (and to argue against my own arguement...)

Bailey's opinion of a relationship was, "(Acarapis woodi) parasite is also widespread and enzootic (endemic), but is independent of paralysis (CBPV)"

I had thought that it was accepted that there was a co-existence between these mites and this virus, (not a cause and effect, like varroa and DWV) it appears I was wrong. And this interesting observation made by Bailey has been dismissed.

HOWEVER, some years ago when I had just started out beekeeping, I was in the No Treatment camp, at the end of the second year my dozen hives all had large numbers of flightless bees with K wings, all symptoms of CBPV, not to mention a lot of Varroa (but surprisingly not that much DWV). I had read about Acarine, etc. etc. and believed bees only had CBPV with Acarapis mites, so I treated for Varroa (I read it would affect A. woodi as well) and in about 10 to 14 days, the flightless bees and the K wings were virtually gone.

All I'm saying, whenever I saw what I believed to be CBPV, I treated as if for Varroa, to kill of the Acarapis woodi mite to get rid of CBPV, it worked for me, but I could have got lucky...

Hope I haven't caused confusion / annoyance, etc. I'm just adding to a discussion, with my opinions / observations

Completely agree.

Although I can offer no proof, I am convinced that the injuries bees suffer from mite bites make them more venerable to catching disease.

So weather the mites are a direct vector or not, I think they still contribute to the spread. And I think the mites make the bees less healthy, making them generally more prone to pathogens.

In turn, I think the viruses make the bees more prone to mites as they become more exhausted and less likely to groom and combat the mites. So I think it is a cycle that can cause rapid decline if left unchecked.

I am convinced the first step for treating any sick hive is to check for mites and treat if needed. (unless foul brood, in winch case check the latest official advice)

 

[jenkinsbrynmair]

I am convinced that the injuries bees suffer from mite bites make them more venerable

Like the Mediaeval historian Saint Beede you mean

 

[jeff33]

Thanks for sharing Emyr, interesting concept which makes sense. Any chance of bees absconding once they have recovered if left without a floor for too long?

 

[jenkinsbrynmair]

Any chance of bees absconding once they have recovered if left without a floor for too long?

I've no idea, doubt anyone has left them like that for an extended time, but I wouldn't have thought so - floors are just a human concept anyway - had a feral colony near one apiary (sadly they died out this spring after surviving for at least five years) in a hollow oak tree which, together with a small top entrance was totally open at ground level (you could look up and see all the comb)
It also almost always had a couple of wasps nest within yards of it.

 

[Hebeegeebee]

Thi

I wish I had tried the remove floor approach.
In April I had a WBC colony on double brood (16 frames of brood)+ 2 supers. They went from looking great to piles of dead bees in a couple of weeks. I tried a variety of solutions as advised by club and BI; re-hiving into a clean hive , regularly clearing the hive floor, shake out - all failed. By June there were still plenty of bees (Q had kept up with the huge losses) but there was little in the way of stores compared to my other hives. Clearly the foragers were dying off early. Eventually they went queenless (? why) and I decided to exterminate them as they seemed doomed (unable to build up stores) and were a risk to my other hives in my garden- I dont have an "isolation" apiary only the far side of the garden.
Maybe an open floor would have helped - without trying I dont know. But next time I will.

This is broadly similar to a colony of mine this year. However they managed to produce a scrub queen which mated with a good brood pattern and the CBPV stopped. The colony is still small in bee numbers but with 7 frames of brood and has thrown up one supercedure queencell which I have destroyed. I have some mated queens available so I will remove the scrub queen and put one of those in.

 

[Hebeegeebee]

Apart from a few significant issues with CBPV, I've had colonies with it that do seem to improve after varroa treatment, so it does seem reasonable that if you reduce one stressor to the colony, it definitely helps. This also coincides with a reduction in colony size in later summer, so they will be less congested.
In my part of the world, spring was rubbish this year, with small colonies that couldn't go out to forage for nectar or pollen, so those spring bees could well have been under-nourished and therefore more susceptable to disease. (No signs of defecation in the hive despite the lack of flying). I did treat this colony for varroa this spring - minimal mite drop and also moved the colony onto clean frames (bailey exchange) with no immediate effect from either. And it was hardly congested as it was so weak.
I have not seen CBPV transferred to neighbouring hives (despite them being 2 or 3 feet either side on some occasions). So is CBPV a queen problem in the way that Chalk Brood or Addled Brood is?

 

[Erichalfbee]

I would be loathe to put a healthy queen into a diseased hive. Maybe somebody could try it

 

[bobba]

Like the Mediaeval historian Saint Beede you mean

I had to re-read what I written about 20 times before I got that one, but I got there in the end.

We both know by now, its only a matter of time until the my next gaff .

 

[cwinte]

Just planning how best to do "the drop"... Quite a lot of wasps here so I spent a while on designs that allowed the floor assembly to be slid into a super-eke but just too hard to make the result stable and wasp/bee proof. So plan 2 was to use a black bin bag pinned to a small eke... with the bag base pinned up at the front and an observation board at an angle sloping to the back so I can get in behind and take samples or counts etc.
Will probably cut a flap or hole for access and peg it closed...

can you see any problems with this or better ideas?
Collects and somewhat hides the dead while keeping out wasps etc (ok, need to tape over that corner gap).
Virtually no cost, standard parts to hand, 5 minute job.
An improvement would be a folded board that makes a flat-ish funnel guiding all to the centre point but I have no spare material to mess and folds angling across corrugations are awkward. Maybe in card...

 

[Sutty]

How about a "drawer" at the bottom of a long drop which you can fill with liquid disinfectant. Entrance immediately below the brood. Could have it without an open base but far enough down for the bees not to go down there.

 

[cwinte]

can you see any problems with this or better ideas?
Collects and somewhat hides the dead while keeping out wasps etc (ok, need to tape over that corner gap).
Virtually no cost, standard parts to hand, 5 minute job.
An improvement would be a folded board that makes a flat-ish funnel guiding all to the centre point but I have no spare material to mess and folds angling across corrugations are awkward. Maybe in card...

Just realised bees and wasps can probably chew through that pretty easily if they want to, hopefully they might not feel the desire but...
Using a heavier weight and/or harder plastic makes the construction trickier and can't think of an easy source right now either.
I do have some sheets of heavier plastic that chicken feed or furniture were delivered in...

 

[cwinte]

Modified this idea to use a feed bag slit down the sides to create a long strip about 7ft long and 20" wide. The long side attached to the inside of a 12mm eke and then a bit of fold to wrap, taping joins to make a funnel of the length, direction and angle desired. In fact I made it too long and then trimmed in situ so I could place a stainless Balti bowl of water a catch-pot on a bit of stone slab. This provides a seal but Easy to move stone and drop out pot to estimate volume of bees.

It hangs a bit neater after the trim at the tip.

Moved supers off; moved stand+floor+brood+half and QX away (hard due to legs catching on long grass); cleaned the dead away from my ground tiles, placed stand and eke-funnel; moved QX+brood boxes back (not the floor), then put supers back on (kept one to harvest and put a new box of clean frames).

Waited a while, took a pic, realised they were all massing on the front ..... as I had not made any entrance!!
Luckily some bee height oak wedges I keep handy with my tools inserted at the front made good and 5mins later all seemed back to normal.

Doing it again I'd notch my entrance in the eke and tape the plastic to the bottom of notch, or maybe not as that spoils my eke and this is actually fine for a while, a few weeks maybe.
In fact... any one have idea how long I should run with the drop arrangements?
I guess I will find out by my observations what the impact is. I plan to pour catch every few days into a kitchen measuring jug, drain any water and estimate volume of bees - the water should not make much difference as long as it is not making them decompose more (note to self: do not leave too long!)

[EDIT: I found a bowl of water a bit too India-Jones. In through the front door, no floor, oh you've fallen into water... I'll see how a simple pot gets on after 24H for them to get used to the new entry challenges. A pot with a cloth wrap around the funnel tip should make a seal and avoid deaths.
OTOH making life tough selects the fittest, so long as HRH does not drop in the water!]