new research suggests treating only heavily infested colonies for varoa.

[user 6228]

http://www.ibra.org.uk/articles/Exploring-good-strategy-varroa-treatment
Article Title


Exploring a treatment strategy for long-term increase of varroa tolerance on Marmara Island, Turkey
Author(s)


Ibrahim Cakmak and Stefan Fuchs
Abstract


We explored practical steps to implement a sustainable treatment against Varroa destructor which is adapted to common beekeeping situations, and applies conventional control but nevertheless exerts selection pressure towards increased mite tolerance in honey bees. This approach approximates conditions of natural selection in host-parasite systems, and is supported by evidence that the impact of V. destructor decreases when bee populations are overexploited by the parasites. However, instead of a “live or let die” approach to selection, which is not feasible for commercial beekeeping, death of highly infested colonies was mimicked by treatment and requeening. We established a feasible treatment threshold based on powder sugar shaking of worker bee samples in 250 colonies kept by four beekeepers on the island of Marmara, Turkey. We subsequently requeened heavily infested colonies with queens from lightly infested colonies using simple methods. We found that although one third of the colonies were routinely left untreated, it was possible to decrease mean mite infestation levels and maintain a stable bee population in our apiaries.

 

[BobsBees]

Varroa treatment.

I have been doing similar with my remaining hives here in Kent.
Past two years NO treatment in Autumn whatsoever.
All i have done is dribble 5ml per seam of bees in each Hive with Oxalic Acid.
This was carried out after Christmas but before the end of January on a day when the temperature reached 10/12c so as to prevent heat loss in the hive as much as possible, although if you are organised it only takes max of two minutes to complete the dribble. Hardly any bees fly out from the frames.
In one hive I did carry out a double treatment 2 weeks later. The result was a very similar mite drop to the first treatment, I was most surprised and still do not understand why this was.
I am considering do the same this year if the Colonies look strong enough.
Older more experienced beekeepers have frowned upon this procedure, but the hive in question did survive as did the queen.
Beekeeping is very much, "If it works for you its ok"
Comments please.
Bob.
Neo-nics.

 

[BobsBees]

Varroa treatment.

I also now think that our Honeybees in the UK are beginning to self treat and control to some extent the infestations they get in the summer months.

Bob.

 

[mbc]

I also now think that our Honeybees in the UK are beginning to self treat and control to some extent the infestations they get in the summer months.

Bob.

Me too, its definitely happening in some areas.

 

[Norfolk]

I also now think that our Honeybees in the UK are beginning to self treat and control to some extent the infestations they get in the summer months.

Bob.

Fingers crossed eh!

 

[jenkinsbrynmair]

Ibrahim Cakmak and Stefan Fuchs

Sure this in't a wind up Derek?

IAll i have done is dribble 5ml per seam of bees in each Hive with Oxalic Acid.

I'm beginning to feel that this is a more important anti varroa treatment than Apiguard in the autumn.

 

[itma]

...
I'm beginning to feel that {Oxalic in Winter} is a more important anti varroa treatment than Apiguard in the autumn.

Yes, in terms of reduced mites for the year ahead.
However the idea of an Autumn treatment is to maximise the vitality of the "winter bees" - which is a worthwhile end in itself.

If one was to do one treatment a year, and ignore varroa between times (actually NOT a good idea, imho) then I would agree that the Winter Oxalic was the one to go with.
But much much much better as part of an IPM scheme.


However, all this is quite a long way away from the thesis of the paper mentioned in the OP, where treatment was accompanied by requeening (with a new Q from a low-varroa colony), to promote any genetic resistance to varroa.
Not sure its a method that is applicable to small-scale (hobby) beeks, but it might be interesting for those that could "play the numbers".

 

[jenkinsbrynmair]

where treatment was accompanied by requeening (.

So maybe skewing the data a bit then - reduction of varroa population partly due to brood breaks?

 

[Cazza]

So maybe skewing the data a bit then - reduction of varroa population partly due to brood breaks?

That is a very good point.
Cazza

 

[Finman]

.
You should know what happens to untreated colonies.

Past two years NO treatment in Autumn whatsoever.
All i have done is dribble 5ml per seam of bees in each Hive with Oxalic Acid.
.

I have treated 10 years only with oxalic trickling. That system does not work.
Late summer treatment is much more succesfu,l (thymol or formic acid)

.

 

[user 6228]

So maybe skewing the data a bit then - reduction of varroa population partly due to brood breaks?

you need to read the full paper.
3 levels of mite infestation and 3 levels of action
low => no treatment no requeen
med => treatment no requeen
high => treat and requeen

as time progressed the number of hives in the low category increases

 

[Finman]

you need to read the full paper.
3 levels of mite infestation and 3 levels of action
low => no treatment no requeen
med => treatment no requeen
high => treat and requeen

as time progressed the number of hives in the low category increases

I have never seen that kind or stardards in productive hives, but in breeding cave many save the colonies before mites kill them.

Mite douple itself in a month. Counting does not help.


low 100 June....200 July...400 August---800 September .. Critical border


10 in January and you have in September 1000 mites.

.Why you should wait that mites violate your colonies?

.

 

[Finman]

.

New Zealand started its own varroa tolerant breeding project in the year 2007.
It has lasted now 6 years. I have not seen results, how tolerant the colonies are.

The start was imported from Germany, where it had allready breeded quite long time. Bee are Carniolans.

Then they got a closed mating station on Mercury Island.

 

[Hivemaker.]

.
I have not seen results, how tolerant the colonies are.

Up to 2012............


However, with funding for the $2 million project having run out and few beekeepers with either the resources or technical ability to take it over, the programme was in danger of folding before any attempt could be made to see if it would work commercially.

Unwilling to see the research or the VSH bees go to waste, Nelson Honey and Marketing owner Philip Cropp and the manager of his beekeeping company, Rae Butler, have agreed to pick up the breeding work in the hope they can convince enough beekeepers it is a viable option in the fight against varroa.

"They offered it to all beekeepers around New Zealand and there was only a couple who looked at it because it is quite a daunting project as it needs someone with a bit of vision who is willing to give it a go and see if they can move it to the next stage," Mr Cropp says.


http://www.stuff.co.nz/nelson-mail/features/primary-focus/6453811/Saving-our-bees

 

[Finman]

.
The Project of Varroa Resistancy NZ 2008, the result



The hives were assessed for resistance in autumn 2008. Only 2 hives were determined to be resistant to varroa. One colony was able to survive without treatment for 13 months andthe second colony was able to survive without treatment for 23 months. Colonies were
produced from these 2 lines and are being maintained at Ruakura until spring 2009.

***************
It seems that the start was almost Minimum succes. There were 64 hives at the beginning.
It must be a disappoinmet that 2 selected hives and not so long livind...

.

 

[Finman]

.
Varroa tolerance Italian bees 1984-2000? on Brazil Island
http://www.ncbi.nlm.nih.gov/pubmed/14963842

There was a honey bee population on an isle which was not treated during 15 years varroa contamination. Seemengly the populationn did well.

Queens were brought to Germany and varroa tolerancy was compared to Carniolan colonies.


Summary: A significantly greater proportion of damaged mites were found in the Carniolan bees (42.3%) and 22.5% were collected alive. The most frequent kind of damage found was damaged legs alone, affecting 47.4% of the mites collected from debris in Italian bees, which was similar to the amount found in Carniolan colonies (46%).

The mean infestation rate by the varroa mite in the worker brood cells in the Italian bee colonies was 3.9% in June and 3.5% in July, and in drone brood cells it was 19.3% in June. In the Carniolan honey bee colonies the mean infestation rates in worker brood cells were 3.0 and 6.7%, respectively in the months of June and July and 19.7% in drone brood cells in June.

In conclusion, the 'Varroa-tolerant' Italian honey bees introduced from Brazil produced lower percentages of damaged mites (Varroa destructor) in hive debris and had similar brood infestation rates when compared to 'susceptible' Carniolan bees in Germany. In spite of the apparent adaptation of this population of Italian bees in Brazil, we found no indication of superiority of these bees when we examined the proportions of damaged mites and the varroa-infestation rates, compared to Carniloan bees kept in the same apiary in Germany.

******

When brought to Germany 'Varroa-tolerant' Italian bees did not showed tolerancy more than normal bees.