Understanding my varroa levels before trying TF

[Andy]

I am going to try TF ala Westerham association. So a I'll go for the slow start utilising the queen frame traps next Jul. Most of my 8 colonies are in a mix of diy UFE and nucs so I have no way of really seeing the varroa count post sublimation recently. Two hives have mesh floors and boards which I describe below. I wasn't really looking for any of the key resistance markers through the year as I've only made the decision in the last few weeks to try TF. I don't think I've seen any evidence of larvae being cannabilised.

Last year I had only two colonies and they both had very few varroa post miticide treatment (20 ish per hive), around 1 or 2 post sublimation in Dec. I had already decided to scrap the miticide this year as an experiment, so the first treatment this year was the sublimation late Nov. This was done at 12ºC outside temp.

The first hive was created from a split in mid May and has had a few bees taken for starting apidea in Jul. It was made up of all but one of the brood from the split and also all the flying bees but had to make its own emergency queen cells which took a while to mate in the poor weather. A frame was also moved into another hive to start it from scratch. The new queen didn't start laying until around 20 Jun. That's about 5 months for the varroa to multiply.

The second hive was created early Jul from a split of my evil hive. It also had various brood frames added from other hives and a queen kindly donated from someone else.

I never really saw any mite drops on either of the boards during the year, but at the same time I seem to have very few mites at the end of the season. Is it the manipulations that have caused the low varroa counts or have I got a good starting point for trying to go TF? According to models (Randy's excel sheet) I should be having an 600 or so dropping in Dec, but that is two years running with very few varroa dropping post treatment.

Next year, I plan to do more extensive monitoring and am designing some UFE that will have screens. ( or I might just buy the boards from abelo). I also have the sugar shaker ready to go.

 

[Sutty]

It sounds like they both had significant brood breaks which may have helped with mite numbers.
In your position, and interested in going treatment free, I'd just do it with one of the two hives so you can compare. If it all goes bad you hopefully still have a hive to split from.

 

[Murox]

This year in particular I have seen virtually no varroa, I put that down to the extended abysmal weather which in my case resulted in extended brood breaks in several hives. The nearest other apiaries to my own are around 3-4 miles so I expect that helps. In the normal run of events I find very few varroa in my hives probably due to luck, location, brood breaks both natural & enforced and I use a sacrificial shallow for drone brood in each hive. I also use vaporisation at this time of year and I do use non temperature dependant strips after I take the honey off.
How many seasons do you base your plans on ?

 

[Andy]

This year in particular I have seen virtually no varroa, I put that down to the extended abysmal weather which in my case resulted in extended brood breaks in several hives. The nearest other apiaries to my own are around 3-4 miles so I expect that helps. In the normal run of events I find very few varroa in my hives probably due to luck, location, brood breaks both natural & enforced and I use a sacrificial shallow for drone brood in each hive. I also use vaporisation at this time of year and I do use non temperature dependant strips after I take the honey off.
How many seasons do you base your plans on ?

Well, it seems like it took Westerham about 5 seasons to have decent results. But from all my reading, it seems that successful TF free beekeepers obviously have the lucky roll of the dice in having a decent resistant queen in the first place and possibly the backup of a local population. I'm still trying to work out if there are many feral colonies locally by asking around. Not having really been looking for the signs of pupae in the bottom of my hives I am not sure where I stand with my present colonies either. I have a queen from someone locally who has found that they have consistently had low varroa as they have reduced their annual treatment so fingers crossed that one might be a good starter.

I've just read 'The Honey Bee Solution to Varroa. A practical guide for beekeepers' which is quite interesting. It details the steps for those aiming to go TF.

 

[Beesnaturally]

Putting out bait hives will give you a developing picture of what is in your locality. In my experience the chances are that these days the feral population will be much higher than the beekeeper population. Obviously you want to avoid catching 'keen' beekeeper swarms.

My top tip: put out 2 or 3 bait hives (I find 6 frame double nucs work best) with a good quality pheromone above the entrance, and space for the bees to cluster inside, close by each other. My theory is that 2 or 3 groups of scouts report back a nesting site, which is a more powerful draw than just 1 group. Also, there is often a 'defending' period leading up to a swarm arriving. If 2 or 3 colonies have lined up a hive, and are defending it, there is a good chance of getting 2 or 3 swarms!

Varroa: its important to know that what works isn't having no varroa, but having the right sort of varroa. That is, the low fecundity strains that bees (inadvertently?) 'breed'. This is important. A few incoming high fecundity mites need to have that trait diluted before they become dominant. So treating because you have a few varroa might be exactly the wrong thing to do.

This is compiled from observations of 15 years of 'live and let die.' In the early days most died. Now very few do - no more than can be accounted by poor supercedure. My local population loves me - I can bait in 15 swarms a year without any trouble. I do my utmost not to disturb their heath and vitality-seeking process. I never look for, or at, varroa. That's the bees' business to sort out.

 

[Swarm]

Host/parasite symbiosis.
It certainly helps to be in an area with limited introduction of new bees, not entirely for the introduction of different bees but the different pathogens they may bring with them.

 

[Amari]

I never really saw any mite drops on either of the boards during the year, but at the same time I seem to have very few mites at the end of the season.

Apols for wandering from your main theme but I was puzzled by varroa counts after vaping OA (sticky paper on varroa board under OMF) two weeks ago.
Home apiary: three hives with mongrel Qs - each hive had 50-100 varroa drop/3 days. I decided to vape a second time.
Out apiary one mile away: two hives with Ged Marshall Qs inserted 21/06 - each hive = 1-2 varroa /3 days. No repeat vape.
I'm puzzled by this difference between the two apiaries.

 

[Beesnaturally]

Host/parasite symbiosis.
It certainly helps to be in an area with limited introduction of new bees, not entirely for the introduction of different bees but the different pathogens they may bring with them.

Yes. Things to avoid are (low resistance bees/high fecundity varroa mites) and the genes of imported queens - both for the first reason, and because local wild/feral (co-evolved) colonies are well adapted to climate and forage, and imports are not.

That I suppose is what I was trying to communicate with the description 'keen' beekeepers.

 

[Andy]

Thanks all. I am high 220m up in the N of Scotland so I am wondering just how many feral colonies are close by.

Sounds like, I shall be trying the bait hives this year as well then . I can always drop one lower down the valley at some friends I guess.When you say double nuc, I presume you mean two boxes high with frames only in the top box. I have some abelo nucs I can do that with.

It's an interesting point that the parasite must evolve not to be too damaging to its host as well. I think there are a few beekeepers round me that employ a 'let the bees get on with it' approach so I'm hoping that this will help. I appreciate that we are not aiming for zero mites but peaceful coexistence.

 

[Andy]

Apols for wandering from your main theme but I was puzzled by varroa counts after vaping OA (sticky paper on varroa board under OMF) two weeks ago.
Home apiary: three hives with mongrel Qs - each hive had 50-100 varroa drop/3 days. I decided to vape a second time.
Out apiary one mile away: two hives with Ged Marshall Qs inserted 21/06 - each hive = 1-2 varroa /3 days. No repeat vape.
I'm puzzled by this difference between the two apiaries.

From my studying and the replies on here, I think the brood breaks makes a tremendous difference to the number of mites. It's interesting that the Westerham beekeepers have a brood break because they make a small split taking the queen out of the hive in the spring. I was wondering what happens to their colonies if they don't make the split. Can the bees keep on top of the varroa in that situation?

@Beesnaturally, do you split your colonies each year?

 

[Erichalfbee]

I'm puzzled by this difference between the two apiaries.

Any brood in either?

 

[Beesnaturally]

Sounds like, I shall be trying the bait hives this year as well then . I can always drop one lower down the valley at some friends I guess.When you say double nuc, I presume you mean two boxes high with frames only in the top box. I have some abelo nucs I can do that with.

No, I put in 12 frames but with an inch or two of starter strip only. Bees like to be able to cluster in a ball apparently. And I like to give them a clean start - scorched hives, new/boiled frames. I find they take to any old hive, but the double nucs (esp in clusters) are by some measure most popular. Put them out early - scouts will note them. Having a smelly fire or two will likely help as well - perhaps select the wind direction...

It's an interesting point that the parasite must evolve not to be too damaging to its host as well. I think there are a few beekeepers round me that employ a 'let the bees get on with it' approach so I'm hoping that this will help. I appreciate that we are not aiming for zero mites but peaceful coexistence.

Prey and parasite are always in an 'arms race' relationship. That makes constant natural selection essential.

 

[Beesnaturally]

From my studying and the replies on here, I think the brood breaks makes a tremendous difference to the number of mites. It's interesting that the Westerham beekeepers have a brood break because they make a small split taking the queen out of the hive in the spring. I was wondering what happens to their colonies if they don't make the split. Can the bees keep on top of the varroa in that situation?

@Beesnaturally, do you split your colonies each year?

I just set them up well in spring and take the honey. The bees (the local population) takes care of medical issues, and I do my utmost not to get in the way.

 

[Amari]

Any brood in either?

I don't know - I didn't look and I didn't study the nature of the uncappings dross.

 

[Erichalfbee]

I don't know - I didn't look and I didn't study the nature of the uncappings dross.

That may… and I stress may… be an answer

 

[alancooper]

Yes. Things to avoid are (low resistance bees/high fecundity varroa mites) and the genes of imported queens - both for the first reason, and because local wild/feral (co-evolved) colonies are well adapted to climate and forage, and imports are not.

That I suppose is what I was trying to communicate with the description 'keen' beekeepers.

Interested in knowing more about the terms low/high varroa resistant bees and low/high fecundity varroa. Not familiar with them and cannot find published references to them. Can you help with this?

 

[Beesnaturally]

Interested in knowing more about the terms low/high varroa resistant bees and low/high fecundity varroa. Not familiar with them and cannot find published references to them. Can you help with this?

This looks like a good article Alan. As I understand it, targeting cells with many mites in them results in dominance of mites with low fertility. (I should probably have used that term.) Mites that can only raise say 2 offspring on average will, all else being equal, increase their population much more slowly than mites than can raise say 5-6 in every generation. (2*2*2*2 is a much smaller number than 5*5*5*5)

The uncapping and recapping behaviour is selective, taking out only high fertility mites while leaving the low fertility ones alone. And the trait of rate of fertility is heritable.

The bees thus 'breed' low fertility varroa - which is much more manageable. Furthermore the low fecun - sorry - fertility mites provide protection against ingress of high fertility mites, immediately breeding out the trait.

I think that might be a slight mix of my own thinking and the orthodox - I'm not much of a student of the scientific studies.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8080770/

 

[ken in NH]

It is my understanding that the mite- resistant strains are better at grooming- removing mites and killing them. One variable not often discussed is their ability to SEE them on other bees- in the dark interior of a hive. letting a little light in might make a world of difference- thoughts? perhaps a clear plastic cover? or......

 

[Beesnaturally]

It is my understanding that the mite- resistant strains are better at grooming- removing mites and killing them. One variable not often discussed is their ability to SEE them on other bees- in the dark interior of a hive. letting a little light in might make a world of difference- thoughts? perhaps a clear plastic cover? or......

There are several strategies the bees use to control varroa. It seems most likely to me that more successful strategies will come to the fore by natural selection at all times, and that bees will cycle through and combine them:

"The proposed framework attempts to explain how Varroa resistance may develop in honeybee (A. mellifera) populations. The framework suggests that resistance is a sequence of events that generate the key traits (increased recapping, brood removal and mite infertility) rather than a single trait [21,47]. Here we found that the enhanced expression of these three key traits is common among resistant populations. This independent occurrence of the key traits within colonies across the world could be an example of parallel evolution [27], because while the recapping and removal behaviours predate Varroa, they have been co-opted to control Varroa, recapping is rare trait in mite-naive colonies, but occurs at low and high levels in susceptible and resistant colonies respectively [33,40]. Similarly, other traits such as brood suppression of mite reproduction [48], or DWV tolerance [49,50] may complement those within the framework. "

https://pmc.ncbi.nlm.nih.gov/articles/PMC8334839/

 

[alancooper]

Mmmmmmmm. Thanks for the two papers but I will pass on contributing to the thread.