Bald Brood

[user 3509]

Just a simple question - does bald brood only affect drone brood? We have discovered bald brood in one of our hives but it is only affecting some of the drone brood. There is no sign of wax moth.

 

[masterBK]

Unfortunately not a simple answer. Bald brood can affect both worker and drone brood. While most of it is down to the tunnelling activity of wax moth larvae there is a genetic form whereby the larvae doesn't produce the capping pheromone needed to trigger the workers to seal the cell on the 9th day. This is down to a recessive allele of the capping pheromone gene so whereas haploid drone larvae with just a single gene don't get sealed in their cells Worker larvae being diploid need the recessive allele on both loci of a chromosome pair. (ie homozygous recessive). Genetic bald brood in worker bees is an indicator of the degree of inbreeding and usually only affects a tiny proportion of the worker brood.

 

[Eyeman]

Anyone else seeing more than the odd few cells of bald brood this season. I've notice the typical line of bald brood associated with wax moth despite the colony being very strong. Also seeing the odd worker cell here and there typical of the genetic form; these are mainly in nucs. I'm re-queening these. I'm surrounded by lots of other beekeepers with imported stock not to mention a commercial guy so the genetic diversity should be high. I've watched the bald brood in a couple of nucs since first inspections in April and it definitely waxes and wanes possibly suggesting an environemenal contribution or just due to the drone mix of the queen?

 

[tonyofarr]

I will put my head above the parapet and suggest a viral connection. I started seeing this about 3 years ago and last year I had all my colonies inspected by the SBI who told me there is a bad virus across the uk killing bees, this virus is not named yet. Some of the larvae are killed at a young stage and look a little like efb until you start to pull them around with tweezers to expose their guts. There are other bee larvae that are dead still sealed in their cells, these are close to emerging and their tongues are sticking out like you see with a hive collapsing from varroa.
I was told by the SBI that others have tried to treat it by shook swarm and it made no difference. At the moment there is no research being carried out into this virus.

 

[Eyeman]

Think you might be confusing bald brood with something else. The pupae look healthy they just don't have any cappings. Word on the street is they emerge as normal bees.

 

[Finman]

Much varroa makes bald brood too.

.

 

[Eyeman]

Much varroa makes bald brood too.

.

The uncapping you get with varroa hygienic behaviour leads to the pupae being chewed and removed. The bald brood pupae remain intact and show no signs of damage. The egdes of the cappings are also raised above the adjacent cappings in bald brood.

 

[Finman]

The egdes of the cappings are also raised above the adjacent cappings in bald brood.

Yes, so it is.

 

[Eyeman]

One of my nucs keeps throwing up the odd frame of bald brood which then disappears with the next brood cycle. The cappings are the typical raised ones associated with moth or genetics. Can't see any signs of the pupae being chewed like you see with varroa or any bees with DWV. Any suggestions? I've just OAV them so will see what the drop is like.

 

[beeno]

I will put my head above the parapet and suggest a viral connection. I started seeing this about 3 years ago and last year I had all my colonies inspected by the SBI who told me there is a bad virus across the uk killing bees, this virus is not named yet. Some of the larvae are killed at a young stage and look a little like efb until you start to pull them around with tweezers to expose their guts. There are other bee larvae that are dead still sealed in their cells, these are close to emerging and their tongues are sticking out like you see with a hive collapsing from varroa.
I was told by the SBI that others have tried to treat it by shook swarm and it made no difference. At the moment there is no research being carried out into this virus.

I have problems with a swarm I collected which is dwindling and now closed up. I have put it down to acute Sacbrood virus. Shall discuss it with SBI when I see him on Saturday.

 

[birdsandbees]

I've just had a visit from the SBI he did comment on some of the bald brood seen, healthy looking larvae inside, his suggestion was varroa load, common at this time of year and suggested that the workers don't cap the cells as they are aware that there is a mite in the cell.

sounds plausible?

one colony had some sac brood so I'll re queen them at the weekend but other than that all okay.

 

[Lancs Lad]

I have had bald brood in my stocks for the first time this year, and during my last inspections I noticed that it was only in the stocks with Open Mesh Floors, and not in any stocks with solid floors.I have only got 5 OMG left , these are Paynes and wax moth larvae were under the mesh, the bees had propolised over the larvae. Could the rise in bald brood be linked to the use of OMF? By the start of next season I will be 100% solid floors.

 

[Eyeman]

I have had bald brood in my stocks for the first time this year, and during my last inspections I noticed that it was only in the stocks with Open Mesh Floors, and not in any stocks with solid floors.I have only got 5 OMG left , these are Paynes and wax moth larvae were under the mesh, the bees had propolised over the larvae. Could the rise in bald brood be linked to the use of OMF? By the start of next season I will be 100% solid floors.

I have the same problem with patches of bald brood that seem to come and go. Some are definitely due to wax moth others could be linked with varroa although the bees aren't removing the pupae which one would expect with VSH. Interestingly Im only seeing it in my nucs and not in the main colonies.
All my colonies are on OMF's so don't think its related as this is the first season I've seen any significant bald brood.
Was also wondering if its due to genetics but it also present in some bought in queens.

 

[For want of a better word]

I will put my head above the parapet and suggest a viral connection. I started seeing this about 3 years ago and last year I had all my colonies inspected by the SBI who told me there is a bad virus across the uk killing bees, this virus is not named yet. Some of the larvae are killed at a young stage and look a little like efb until you start to pull them around with tweezers to expose their guts. There are other bee larvae that are dead still sealed in their cells, these are close to emerging and their tongues are sticking out like you see with a hive collapsing from varroa.
I was told by the SBI that others have tried to treat it by shook swarm and it made no difference. At the moment there is no research being carried out into this virus.

Sounds like the Danish Pastry Virus I describes on a thread some time back.
SBI said that NBU/Apha were aware and were now seeking samples at this moment
Will try to attach a photo

upload of file failed was jpeg image.

 

[Eyeman]

Sounds like the Danish Pastry Virus I describes on a thread some time back.
SBI said that NBU/Apha were aware and were now seeking samples at this moment
Will try to attach a photo

upload of file failed was jpeg image.

Found your report in 2017- you said you were going to upload a photo back then!
This was you description:

Capped brood is dead, capping has a swirl effect as in a Danish pastry.
Seems to be prevalent across the UK
SBI information is that this is taking out approx 5%of the brood.
Another imported virus that will probably take its course and vanish in a year or so.

My surprise is that nobody else has reported it!!

If you think that Danish looks like bald brood then you better check out where your local corner shop gets their pastries from.

 

[For want of a better word]

Not BALD.. but CAPPED.. with a swirl to the top that looks like a Danish Pastry

Must need to adjust my images jpg too big *.. will try again!

Failed to upload how do I change size of file???

 

[Hivemaker.]

....like this...

 

[Eyeman]

Sunken cappings are always a worry. Although they don't look greasy.

 

[For want of a better word]

....like this...

I bow to your greater skills in computering!!

How did you do that?

Yeghes da

 

[Stiffy]

....like this...

More like a donut than a pastry!
Bet it’s varroa related, most bee problems seem to be. And like most creatures, if severely weakened, diseases can take hold.
S