Dodgy 'bald' brood

[boywonder]

Hi all,

Was looking at my wife's hive with her this afternoon. This is a very advanced colony for this time of year. 14x12, with 8 frames of BIAS - much of it wall to wall. Great looking brood pattern, cappings, and larvae.The bees were great in number, and were calm and healthy-looking. There is a good amount of drone brood at the edge of the nest on the verge of emerging, and there were a handful of play cups..... So all in all, a booming colony on the verge of great things (or swarming preparations!).

To the best of our knowledge/observation, it has not suffered with any wax moth infestation.

In and amongst the general excellence described above, we did spot one small area of 'classic' bald brood on one frame, which we glossed over.

However, on a second frame in a different part of the brood nest, we saw another patch of bald brood, but here the late-stage pupae were clearly dead and/or deformed. Even the open brood (larvae) in this area of the comb were somewhat less than 100%

I am not suspecting any heinous brood disease, but can't pinpoint the likely culprit for this dodgy/bald brood. I'm not discounting wax moth damage, but what is pictured feels atypical.

We'd obviously welcome any thoughts/comments (well I would, so I can claim the brownie points )

Thanks in advance.

 

[ericbeaumont]

Doesn't look like classic bald brood, in which larvae are fully formed (but without cappings) and emerge normally. Look closely and you will see that bees have chewed the larvae in an attempt to clear out the brood; other cappings have been opened as the bees recognised a problem.

When bald has taken over brood would look very pepper-pot, like the frames shown by Laurence in this video. Your bald is caused by varroa, and shows bees' attempts to remove damaged brood. Have a look at Fig.4 at Scientific Beekeeping: The Varroa Problem, Part 5, and you may see the similarity with your brood.

 

[boywonder]

Doesn't look like classic bald brood, in which larvae are fully formed (but without cappings) and emerge normally. Look closely and you will see that bees have have chewed the larvae in an attempt to clear out the brood; other cappings have been opened as the bees recognised a problem.

When bald has taken over brood would look very pepper-pot, like the frames shown by Laurence in this video. Your bald is caused by varroa, and bees' attempts to remove damaged brood. Have a look at Fig.4 at Scientific Beekeeping: The Varroa Problem, Part 5, and you may see the similarity with your brood.

That's excellent advice - thanks Eric. Good resources, too. Thanks.

I had considered the possibility of varroa being the root cause, but I generally haven't equated varroa in cells with pupal death in this way. Every day a school day.

 

[user 819]

I would likely say varroa too , there are some perforated cappings amongst the brood. The bees must have some hygenic traits and are simply outing the infected larvae they sense, worthy of keeping the genes going and increasing from that particular Q or use her as a cell raiser.
There is no evidence of WM tunneling thru the cappings or cell tops.

 

[fian]

Diploid drone offspring, the nurses eliminate them naturally by cannibalizing them to reuse the proteins/energy.
You should count the empty cells to calculate the vacancy %.
You should locate a beekeeper nearby (more than 5 km from your apiary), buy a swarm or a queen to increase the biodiversity of the apiary as a preventive measure.

 

[drex]

I can see lots of white varroa poo on the lips of some cells.

 

[jenkinsbrynmair]

I'm sure I saw a varroa in one of the photos

You should locate a beekeeper nearby (more than 5 km from your apiary), buy a swarm or a queen to increase the biodiversity of the apiary as a preventive measure.

 

[Antipodes]

I can see lots of little droplets of nectar mainly on top of the capped cells, particularly in the top photo.

 

[boywonder]

I can see lots of little droplets of nectar mainly on top of the capped cells, particularly in the top photo.

Yep I see that too. The wife laid the first frame she pulled across the top bars, and it was full of recently stored nectar, an amount of which dribbled out onto the frames beneath.

I've been zooming in looking for the white varroa poo which Drex has seen. Also, on the photo with the pulled pupa, I can see what looks like an adult mite climbing into a cell of open brood. Probably what JBM saw.

 

[Antipodes]

Yep I see that too. The wife laid the first frame she pulled across the top bars, and it was full of recently stored nectar, an amount of which dribbled out onto the frames beneath.

I've been zooming in looking for the white varroa poo which Drex has seen. Also, on the photo with the pulled pupa, I can see what looks like an adult mite climbing into a cell of open brood. Probably what JBM saw.

Hi Boywonder,

Yes, excellent photos letting me zoom right in.

Underneath approximately the middle of the stick and seven cells down, I can see a blob of nectar (not dissimilar to the ones in the top photo) just on the inside rim of a cell, but I can't see any adult varroa at all. Never having seen one live however I'd be grateful for you to point out the mite you can see....I'm trying to be "mite aware" down here .

 

[boywonder]

Hi Boywonder,

Yes, excellent photos letting me zoom right in.

Underneath approximately the middle of the stick and seven cells down, I can see a blob of nectar (not dissimilar to the ones in the top photo) just on the inside rim of a cell, but I can't see any adult varroa at all. Never having seen one live however I'd be grateful for you to point out the mite you can see....I'm trying to be "mite aware" down here .

Lol.

What I saw as a mite is clearly a drop of nectar, on second inspection.

It did look reddish brown, and mite-like, but now that I can see it for what it is, I can't unsee the globule, nor get past the realisation that either my eyes or my brain are starting to fail me

 

[boywonder]

Diploid drone offspring, the nurses eliminate them naturally by cannibalizing them to reuse the proteins/energy.
You should count the empty cells to calculate the vacancy %.
You should locate a beekeeper nearby (more than 5 km from your apiary), buy a swarm or a queen to increase the biodiversity of the apiary as a preventive measure.

Appreciate the thinking here fian - left field as it is (vs. the consensus in relation to varroa).

My wife, who is a fetal medicine midwife, and whose bread and butter is congenital abnormalities is certainly interested in this stuff. Genetics are not my strong point, but I understand what diploid drones are, and that the workers are known to cannibalise the brood.

However, two things turn me off this theory.
The first is that, as I understand it, such cannibalism is of young larvae from recently hatched eggs - so, say Day 4/5 open brood, whereas what you see here are pupae close to emergence (say Day 21/22 ish if it were drone).

The second is that, were these cells containing drones, I would expect to see some evidence of these cells having been 'enlarged' (domed) in order to accommodate the drones, and I can't see evidence of that either (in the partially uncapped cells).... Actually I take that back... I can indeed see this. Hmmm.

Whether or not you are on the money, I do appreciate the general need for genetic diversity. Even my own annual interventions in this (garden) apiary alone are possibly enough to convince me that there is already enough genetic diversity / turnover - let alone the actions of other beekeepers in the locality. Interesting stuff. Thanks

 

[fian]

Cannibalism by the workers occurs as a consequence of the difference in composition of the cuticle as it develops, therefore the fact that this has not occurred in the larval stage only indicates that the capacities of the nurses are lower than those of the larvae. common and it is known that they are highly conditioned by temperature during their development.
Possible time sequence:
28 before the current nurses, was there an oscillation in the temperature of the colony (if they are diutinus, in autumn the temperatures began to drop or if they are new bees, was there a thermal drop around March 3)?
These nurses were unable to detect the diploid larvae laid 13/16 days ago that they now remove.

 

[jenkinsbrynmair]

I can't see evidence of that either (in the partially uncapped cells).... Actually I take that back... I can indeed see this. Hmmm.

no, the opened cells with developed pupae in have no evidence of being enlarged for drones