OA pre check

[nemphlar]

Put the sticky boards on last week to check for V natural drop. 4 hives gave 9/8/0/0 counts over the 7 days. Tempted to leave the OA this year and maybe go for an early FA treatment next year. Any strong opinions out there

[Rosie]

I would not allow natural mite drop to drive my choices as it's not reliable enough. I see oxalic acid treatment as my big opportunity to get on top the the little devils. However, I use less than most people and have been getting away with it for years. I usually open some of my hives on mild winter days to monitor egg laying so that I can best judge the application time but during the last 2 winters I never managed to find any mild days so I had to take a guess at when to apply it. Fortunately I seem to have been lucky. I am now waiting for a mild day (over say 8 degrees and bright) to check on eggs.

Rosie

[Neils]

Agree that reading too much into the natural drop probably isn't a great idea especially if deciding not to do something. Off the back of my autumn treatment counts I'll definitely be using OA this winter. I've never been a fan of treating "just in case", but the drops from the treatment more than suggest that a follow up with OA is warranted.

Last year in the run up to autumn my mite drop was negligible, once I started treating however I had hundreds of mites drop; that really hammered home to me that the natural drop should be taken with a pinch of salt especially if it seems to indicate minimal mite population.

[Jon]

I agree with Nellie. Basing varroa treatment on mite drop is a risky business.
I have seen very few mites this year, even during Apiguard treatment in August/September.
I remember last year when I treated with Oxalic most colonies only dropped a few mites but there was one strong colony which dropped over 100.

My bka has its quiz night tonight and I am bringing along 3.3 litres of 3.2% Oxalic to disburse into plastic bottles.
It cost under a fiver to make that and it will treat about 75 good sized winter clusters.

[Jon]

I underestimated the demand as we had an array of empty bottles brought in looking to get Oxalic to treat over 120 colonies.
Will need to make up some more tomorrow.

I did a talk on Oxalic treatment last month and only two of the members had ever used it before so it is good to see them taking the opportunity to zap some mites.

[Calum]

Hi
my 2p, hit them with OA as soon as they are brood free. FA has for me two problems, by the time it is warm enough to use it effectivley the colonies are already well into brood = the varroa you have now have multiplied AND early treatments of FA risk FA getting in your spring honey crop.

[Calum]

I did a talk on Oxalic treatment last month and only two of the members had ever used it before so it is good to see them taking the opportunity to zap some mites.
In our group of beekeepers in Lindau the use is 100%.
In germany I#d say the use is well over 60% the rest favouring perizin or lactic acid which is not much fun for anyone.
Catching them brood free and getting low enough temperatures will be tricky this year I think...

[Jon]

I treated 18 colonies last week.
I have monitored about half of them.
One which I treated 4 days ago had about 150 mites on the board today and will probably drop quite a few more.
Some had no mites at all and others had only one or two.
I have found this in previous years. Even though all were treated with Apiguard at the same time in late summer/autumn, the drop after oxalic trickle varies a lot.

[gavin]

Do you have colonies that seem equivalent in autumn and summer strength, summer/autumn treatment effectiveness, location, current strength, and yet drop very different numbers of mites? Can you see where I'm going with this?

G.

[Jon]

Hi Gav
The vast majority of mine seem to drop very few mites with Oxalic but last year I had a similar one with a big drop as well.
That colony is still alive with the same queen and is going well.
A colony starting the year with a couple of hundred would be in difficulties by June or July if left untreated.
The trouble with making judgements based on mite drop in winter and colony size in autumn is the other variables in play as well such as nosema.
Colonies treat the apiguard gel in different ways as well. Some have it removed within 48 hours, paper and all, whereas others seem to hardly touch it.
I don't monitor mite drop in every colony but try and get a snapshot of what is happening.
Oxalic is cheap as chips and I have not detected any detrimental effect on the bees so I just tend to treat.
PLB on beeline asked me why did I think Oxalic was harmless.
Without doing a massive amount of research I can say from observation that you don't get a heap of dead bees outside the hive the day or two after treatment, you don't find queenless colonies in Spring, and it has got to be better for a colony to start the spring build up virtually mite free.
You can always argue sub lethal effects if you can be bothered - the way they do with neonics. I don't think it is that relevant in either case.

[gavin]

I was just wondering whether you had thought of working Varroa tolerance into the traits that you select for in your queen raising. It does need some thought about assessing colonies in ways that are uniform and likely to give good information on the potential of certain lines.

[Jon]

I see where you are coming from and it is definitely a key trait to select for, but it's hard to know where to start other than ignore Bispham and his ilk.
I do see colonies which uncap pupae, presumably because of mite damage to the pupa.
I don't personally have enough colonies but it could be one of the longer term goals of the queen rearing group.
There are clear differences in daughter queens which are half sisters, presumably due to the different drone fathers.
I had one which just produced chalk brood and the colony dwindled to the point where I put the remnant plus the queen into an apidea where it continued to produce chalkbrood until it got robbed out by wasps. Sister queens of this one seem to be very good.

[chris]

In the paper:

Apidologie 38 (2007) 566–572
c_ INRA, EDP Sciences, 2007
DOI: 10.1051/apido:2007040
Original article
Honey bee colonies that have survived Varroa destructor*
Yves Le Conte, et al.

Yves le Conte, who is rather unbisphamlike, states the following:

"One way to obtain
resistant bees is to intensively select for
single characters that decrease the growth of
Varroa populations. This approach might force
adaptations by the mite, limiting the genetic
progress obtained by the breeder. Another possibility
is to monitor natural selection in unmanaged
populations. An advantage of natural
selection is that it selects for a host-parasite
equilibrium that may be more sustainable than
human selection for a single characteristic."

[Rosie]

I find that the oxalic acid treatment I apply during the winter keeps the mites under reasonable control until my Autumn treatment. It's rare for a colony to need emergency treatment during the summer but when it does occur it's always a particularly strong colony that succumbs. I suspect that selecting for natural varroa tolerance is almost the same as selecting for non prolificacy - which is not necessarily a bad thing, particularly if your small nests manage to deliver high yields.

Rosie

[chris]

I suspect that selecting for natural varroa tolerance is almost the same as selecting for non prolificacy - which is not necessarily a bad thing, particularly if your small nests manage to deliver high yields.


Yes, but the problem is that they found the treated colonies produced 1.7 times more honey than the untreated colonies. It's an interesting paper. If Nellie can give a hand, I'll try to post it.

[Jon]

I think this is the paper (http://www.apidologie.org/index.php?option=com_article&access=standard&Itemid=129&url=/articles/apido/pdf/2007/06/m6118.pdf).

[chris]

Yep, that's it.

[Neils]

Late to the party! If you need a hand linking/hosting stuff, just send me a PM with the details, I get an email.

Interesting article.

[Adam]

I just treat with Oxalic Acid anyway. The Treat and be Dammed approach. Monitoring is still going on but it appears I've got a similar variable result as Jon - I'm counting the drop each day after treatement 4 days ago.
For low-drop colonies, are they rid of varroa or has the queen started brooding so the varroa are safe and snug under a wax capping?

[Rosie]

Adam

The only way to be sure is to take a look. I know we are told not to open hives in the winter but I have often peeped at the centre of the nest in mid-winter on a mild day without problems. I just choose a day when it's over 10 Degrees C and the cluster is loose, and remove an empty end frame. That enables me to slide half the frames sideways to open up a gap either side of a frame in the middle of the nest. I then pull it part way out and have a quick look on either side without totally withdrawing the comb. I would leave them undisturbed if the bees were in a tight cluster. After putting the roof back on you could slide the floor drawer in for a day to help them re-establish the temperature they want but I don't bother to.

Rosie

[susbees]

I just treat with Oxalic Acid anyway. The Treat and be Dammed approach.

I think there's something to be said for that. As long as it's not carried over to Nosema zapping. I had a public head-to-head with a certain guiding light of BIBBA over this last year: random use of antibiotics makes me grumpy.

[Rosie]

I'm with you over antibiotics. I don't even use them when I suspect nosema. Can I just make it clear though that it's not BIBBA policy to promote antibiotics. I think the leading light was speaking for himself.

Rosie

[gavin]

Now I'm curious - but I suppose that it is impolite to ask whether the leading-guiding light looks like santa?!

In any case, if it is the antibiotic I think you're talking about, it will be impossible to find in 6 months.

[nemphlar]

After some deliberation i went with oa sublimation Sticky boards 4days later showing 115/108/1/0 a little surprising that this follows the natural drop I found earlier.
I always assumed large colonies had large v count mainly because of the rate brood expansion and opportunity rather than bee breeding.
One thing I did notice was the only poly hive is bigger with bees apparently free to roam around compared to the wooden hives

[gavin]

Interesting about the polyhive, and it accords with what others say about them. That variation between colonies is always hard to fathom. Some colonies are probably better at just dealing with mites, some have a lot because they had a lot of brood (especially drone brood where they multiply faster) and some pick up mites because they rob out colonies that are collapsing due to Varroa.

[Jon]

Interesting about the polyhive, and it accords with what others say about them. That variation between colonies is always hard to fathom. Some colonies are probably better at just dealing with mites, some have a lot because they had a lot of brood (especially drone brood where they multiply faster) and some pick up mites because they rob out colonies that are collapsing due to Varroa.

That's what I find difficult. Is a big mite drop a good thing or a bad thing and is it possible to extrapolate anything from it given the number of different factors which could be involved.
My mite drops have been like nemphlar's, some with hundreds and others with none at all.

[Adam]

I've got a summary of my varroa count here

http://www.norfolkbee.co.uk/useful-documents/OxalicCleansing2011.pdf

No pattern to mine either.

Gavin, I assume you're saying that Fumidil B will not be available soon?

[Calum]

Good question Jon, I like one good mite drop - at least I know the treatment was effective.
Treating OS at the right outside temp is no garuntee that the colony is sitting tightly in their winter 'knot' which reduces the effectiveness of the treatment (according to the treatment documentation in Germany).
Gavin reinvasion of varroa through absconding bees from collapsing colonies is I think a bigger issue that robbing at this time of year, but it is colder here and I have not seen bees looking for food when they go out even when the next hive is empty (absconded) already. Although Scotland is alot warmer than south Germany at this time of year!

[Calum]

I'm with you over antibiotics. I don't even use them when I suspect nosema. Can I just make it clear though that it's not BIBBA policy to promote antibiotics. I think the leading light was speaking for himself.

Rosie
Illegal here thank goodness. An issue is that in america antibiotics are used to treat foulbrood - this only deals with the symptoms, but not the level of spores in the hive making the problem rampant (but if everyone treats no problem haha). The antibiotics are measureable in imported honey - but that is saleable whereas a german honey containing those antibiotics would be classed as industrial waste and the beekeeper would face a heafty fine. go figure...

[gavin]

Gavin, I assume you're saying that Fumidil B will not be available soon?

I read somewhere that it is now illegal to sell it in the UK, but vendors have a period of grace (6 months?) to sell their current stock.

[susbees]

Now I'm curious - but I suppose that it is impolite to ask whether the leading-guiding light looks like santa?!



That'll be the one. The one with the extra yellow blob on his Jenter plugs that had me trawling the web to see if I was wrong ;)