A Discussion on Foulbrood

[gavin]

In theory ...

- killing the colonies selects against virulent strains of bug and/or susceptible bees

- shook swarming doesn't select for or against resistant bees but might select for virulent bugs

In reality ...

The bugs are under constant selection for virulence anyway. Selecting against susceptible bees may be the strongest effect (in addition to removing inoculum of course).

[The Drone Ranger]

See "Infectious Diseases of The Honeybee " L.Bailey 1963 pages 130 -140 for explanation of why a drop in available incoming food increases EFB infection.
Also resistance and effects of culling diseased hives

You are worse than Eric
Is that the Eric who was banned ??
I think its time to lift the lifetime ban
A couple of weeks in the sin bin should have been enough.
As I remember that was all about inbreeding and got a bit heated
Recently somebody else got a yellow card over chemical abuse
I kind of like the idea that some people are over enthusiastic
If the Forum just had 3 or 4 contributors saying how great AMM are that would be a bit flat.
PS Will.i.am of the Voice has joined BiBBa and is now known as Will,i.amm

[Jon]

Eric was unbanned a while back but hasn't started to post again. Eric we love you. Lets have some more of your blether and nonsense.

I kind of like the idea that some people are over enthusiastic

Me too, as long as it does not descend into shouting or insults. Back to the foulbrood. This thread has already been relocated.

[Bumble]

PS Bumble is actually a burly Stonehaven professional shot-putter who lives with his artist lover in a garret somewhere in southern England .... .... mibbae.

mibbae!

Or mibbae a New Year's Eve Swinger, or mibbae a granny with hair tucked neatly into a bun, or ....

It has been stated often enough that treating in this manner is selecting the most virulent strains of AFB!

Or the most susceptible of bees?

I thought it was standard that AFB colonies, and equipment, were destroyed. Is it different in Ireland?

Fera says, on page 10 of this booklet https://secure.fera.defra.gov.uk/bee...ument.cfm?id=7

Control of the disease [AFB] is through compulsory destruction of infected colonies, which is a very effective measure.

I'm a bit neurotic about the foulbroods you see, and have almost worn out our copies of those bookelts. There was EFB in our area last year you see. We were lucky, I hope we continue to be. RBI is due to inspect our bees soon, to check.

Our bees seem healthy and active, and we haven't seen any signs, so if the diagnosis is positive we hope the inspector would trust antibiotics or shook swarm, but we do know that heavily diseased colonies or infected colonies that are weak are destroyed.

[Ruary]

Sorry wrote it too fast and did not re-read!
Non destructive methods select for the most virulent strains as they are the ones which give rise to clinical symptoms. Some bees can deal with the more benign strains and in that case obviously the pupae do not die, so there are no sunken cappings nor decaying pupae which are the classic signs of AFB.
Destructive methods kill off the bacteria by burning/ burying.

[The Drone Ranger]

Les Bailey tells us that the bees most resistant were those that removed infected larvae before 10 days but removal after that its worse than useless

Now I think that means killing larvae after capping and judging which bees remove the most dead larva might not tell us much

And more importantly after a threshold number of infected larva is reached memory says they used 100 cells both the resistant and susceptible bees all succumbed

Also if the ratio of nurse bees to larva is high, bees reject far fewer infected larva.
That condition can occur when there is a sudden drop in income I think that could be caused by spell of bad weather or the rape ending for instance

It's best to read the book though because taking a few lines here to cover his research seems wrong in a way, so the bits after italics are my views not his necessarily

[Neils]

What's the book title DR?

In relation to removal of infected larvae, my understanding (and it's late so I may be getting mixed up) is that can contribute to the spread as the same bees that are removing larvae are then going on to feed other, so far, healthy larvae and the disease spreads through that cross contamination of removing infected brood then getting, now infected from mouth parts exposed to infected brood, food which is then fed. In some respects might a less hygienic behaviour actually be beneficial?

Hygienic behaviour good for varroa but bad for foul brood? (simplistic I know, sorry).

[Ruary]

What's the book title DR?

In relation to removal of infected larvae, my understanding (and it's late so I may be getting mixed up) is that can contribute to the spread as the same bees that are removing larvae are then going on to feed other, so far, healthy larvae and the disease spreads through that cross contamination of removing infected brood then getting, now infected from mouth parts exposed to infected brood, food which is then fed. In some respects might a less hygienic behaviour actually be beneficial?

Hygienic behaviour good for varroa but bad for foul brood? (simplistic I know, sorry).

I wonder?

It depends on when the larvae are removed if the skin is intact then removal should not cause spread of bacteria from it as all the bacteria (infecting that larva) is contained within it.
Ruary

[Rosie]

I thought the spread depended on whether the larvae had defecated in the cell or not bfore dying. The ones that are not well fed die early and keep the bacteria in their gut. The better fed ones last long enough to defecate and the bacteria is spread whenever the cell is cleaned whether the bees are hygienic or not.

Rosie

[The Drone Ranger]

See "Infectious Diseases of The Honeybee " L.Bailey 1963 pages 130 -140 for explanation of why a drop in available incoming food increases EFB infection.
Also resistance and effects of culling diseased hives

from earlier post

The early removal of larva is in relation to AFB where removing the larva before infective spores have fully developed is key
The resistance trials were conducted using 100 scales introduced to health hives
Some hives could cope others collapsed
Once the number of introduced scales was increased all hives succumbed