Still big varroa drop

[Etton]

Have vaped a couple of hives 5 or 6 times and continues still large drop. Bees now clustering but probably still brood, so should I just keep vaping or wait until end of December when hopefully no brood?

 

[charlievictorbravo]

There seems to have been a lot of this sort of thing this year. I have had a similar problem with two hives. I ended up treating one with Apivar then the other one had a mite drop increasing instead of decreasing. These were both strong colonies, filling 3 and 4 supers during the summer. The Apivar-treated colony is now down to 3 to 4 a day but the other one is up to 70 mites a day after the latest vape. This has been discussed on another thread but no firm conclusion was reached as to the cause - the most plausible being that they were robbing out a weak colony heavily infested with mites, but I have my doubts.

As to what you should do, I'm not sure. The weather we've had recently (don't know what it's been like in Yorkshire) is September-like so maybe no harm in continuing to vape in order to get the number of mites down before the thick of winter, while winter bees are still being brooded.

CVB

 

[Heather]

Frighteningly, I had a beekeeper of 2 years experience saying he still had a bad varroa drop after 3 oxalic vaporisations... each 5 days apart!! Told him queen prob dead anyway with such treatments. Start again!
Do they ever listen. Poor bees.

 

[linoleum bonypart]

Oa vapes don't kill queens !!

 

[madasafish]

Have vaped a couple of hives 5 or 6 times and continues still large drop. Bees now clustering but probably still brood, so should I just keep vaping or wait until end of December when hopefully no brood?

My personal experience is just that: vaping with brood present may not kill all mites.. So I treat very bad cases with Apistan - non temperature dependent - in September ..
Vape again when broodless - Dec/Jan.

 

[Erichalfbee]

Have vaped a couple of hives 5 or 6 times and continues still large drop. Bees now clustering but probably still brood, so should I just keep vaping or wait until end of December when hopefully no brood?

I have had one hive out of 8 behave like that. 7 vapes then Apitraz. They dropped a phenomenal number of mites by the time the strips went in. They are still there but diminished in size and dropping no mites. I agree with CVB. There must be something else going on. Why only one colony? If they were robbing would that robbing be going on for so long? In my experience a hive is robbed out pretty quickly. I think in future if I haven’t got drops down after five vapes the Apitraz will be deployed

 

[Nige.Coll]

We were talking about this in the pub the other night.
Some have used apiguard and had the same result.
6 weeks treatment some have done instead of the usual 4 as the varroa drop after 4 weeks was still very high, they will also be using Oxalic acid during winter in their preferred method either vaping or pouring acid on them.

I have done 4 or 5 treatments on mine and left them BUT mine do have a brood break around September the last treatment didn't have a huge drop. I will be doing another treatment before April but I don't treat them during December and January as a rule.

 

[Nige.Coll]

Frighteningly, I had a beekeeper of 2 years experience saying he still had a bad varroa drop after 3 oxalic vaporisations... each 5 days apart!! Told him queen prob dead anyway with such treatments. Start again!
Do they ever listen. Poor bees.

Oh dear.
Thought you'd know better than that.

 

[Erichalfbee]

Frighteningly, I had a beekeeper of 2 years experience saying he still had a bad varroa drop after 3 oxalic vaporisations... each 5 days apart!! Told him queen prob dead anyway with such treatments. Start again!
Do they ever listen. Poor bees.

That’s not true.
No need to upset the poor chap.

 

[Eyeman]

We were talking about this in the pub the other night.
Some have used apiguard and had the same result.
6 weeks treatment some have done instead of the usual 4 as the varroa drop after 4 weeks was still very high, they will also be using Oxalic acid during winter in their preferred method either vaping or pouring acid on them.

I have done 4 or 5 treatments on mine and left them BUT mine do have a brood break around September the last treatment didn't have a huge drop. I will be doing another treatment before April but I don't treat them during December and January as a rule.

We all have different ideas.
The most important OAV treatment IMHO is the December/Jan one so I did 3 vapes 4 days apart.
I then did another vape to check the 'accelerated drop' in May/June and foun d very little drop.
Then did another x3 4 days apart OAV after supers off in September/October again low drops.

Next year the plan is:
1. Dec/Jan x3 OAV
2. End Mar/April (before supers go on) x1 OAV 'accelerated drop' and see if further OAV needed.
3. End Sep/Oct x1 OAV 'accelerated drop' and see if further OAV needed.

This year I probably didn't need to do my Sept/Oct OAV.
The accelerated drop is IMHO a more reliable estimate of mite number than daily natural drops.

 

[Karsal]

I've vaped all the eleven colonies I have over two weeks at five day intervals and seen a small amount of varroa after each vape.
One hive in particular which was a large swarm I collected in summer has not dropped a single varroa mite after three vapes.
I cannot believe this result and will keep a close eye on the bottom sticky board I've installed under the OMF.

 

[mazzamazda]

Oa vapes don't kill queens !!

When they jump onto the pan they do, I've had it 3 times in less than a year

 

[mazzamazda]

I think for me OA vapourisation is the most inefficient, labour intensive and pretty useless treatment with brood present there is. I wasted 15 full days this year on it, 600 miles travelling and I still lost many bees to varroa. NEVER AGAIN!

I had to treat again with Amitraz and only then did I see a difference in them coming round. It clearly works for some people, not for me. In comparison I treated all the colonies in 1 day instead of 15.

 

[Etton]

When they jump onto the pan they do, I've had it 3 times in less than a year

I vape under the omf. I still think my nadired supers may get in the way of the vapour rising up to the brood box

 

[charlievictorbravo]

We all have different ideas.
The most important OAV treatment IMHO is the December/Jan one so I did 3 vapes 4 days apart.
I then did another vape to check the 'accelerated drop' in May/June and foun d very little drop.
Then did another x3 4 days apart OAV after supers off in September/October again low drops.

Next year the plan is:
1. Dec/Jan x3 OAV
2. End Mar/April (before supers go on) x1 OAV 'accelerated drop' and see if further OAV needed.
3. End Sep/Oct x1 OAV 'accelerated drop' and see if further OAV needed.

This year I probably didn't need to do my Sept/Oct OAV.
The accelerated drop is IMHO a more reliable estimate of mite number than daily natural drops.

You make a number of references to 'accelerated drop' and I have heard this expression before but not sure exactly what it is.

I assumed it was a single vape using the usual quantity of OA for the hive and used to kill 90%+ of the phoretic mites , which you then count over 5 days. Have you calculated a critical level for this 'accelerated drop' - say, 90% (efficacy) of 30% (% phoretic) of 1000 mites (intervention level) = 270 mites or is it more a gut feeling that the colony might need further treatments? How successful have your 'accelerated drops' been in helping you decide on further treatments?

I can see that 'accelerated drop' has the advantage of not disturbing the colony, by needing to take a sample of bees, and is not quite as random as the "natural drop" as suggested on Beebase, which I tend to use.

CVB

 

[Erichalfbee]

You can use any fast acting miticide for an accelerated drop. Even icing sugar will do but is more invasive than OAV.
I work on 80% mites in the brood and OAV kills 95%. I take a 24 hour drop and multiply by five to give me total mites. Anything over 20 gets a course.

 

[mazzamazda]

I vape under the omf. I still think my nadired supers may get in the way of the vapour rising up to the brood box

I vape nucs under the omf too, I certainly see less white bees and it seems to get much less vapour even with a much larger dose. They are usually brood free and under those conditions I think OAV is effective.

 

[mazzamazda]

I vape under the omf. I still think my nadired supers may get in the way of the vapour rising up to the brood box

Have you tried top treating?

 

[Nige.Coll]

We all have different ideas.
The most important OAV treatment IMHO is the December/Jan one so I did 3 vapes 4 days apart.
I then did another vape to check the 'accelerated drop' in May/June and foun d very little drop.
Then did another x3 4 days apart OAV after supers off in September/October again low drops.

Next year the plan is:
1. Dec/Jan x3 OAV
2. End Mar/April (before supers go on) x1 OAV 'accelerated drop' and see if further OAV needed.
3. End Sep/Oct x1 OAV 'accelerated drop' and see if further OAV needed.

This year I probably didn't need to do my Sept/Oct OAV.
The accelerated drop is IMHO a more reliable estimate of mite number than daily natural drops.

Yeah we all do it our own way.

I do treatments to check the amount they have before supers go on and again when they come off.
I don't ever bother with the natural drop it's a pointless exercise.

I've never liked the idea of disturbing them during winter, not convinced a passive method like the varrox would be hugely effective when the bees were clustered but then I've never tried it to find out.

I use a home made tool and a blowlamp now. It's quicker and I don't have to carry a heavy battery around a field. Seems to kill the mites ok.

 

[Eyeman]

You make a number of references to 'accelerated drop' and I have heard this expression before but not sure exactly what it is.

I assumed it was a single vape using the usual quantity of OA for the hive and used to kill 90%+ of the phoretic mites , which you then count over 5 days. Have you calculated a critical level for this 'accelerated drop' - say, 90% (efficacy) of 30% (% phoretic) of 1000 mites (intervention level) = 270 mites or is it more a gut feeling that the colony might need further treatments? How successful have your 'accelerated drops' been in helping you decide on further treatments?

I can see that 'accelerated drop' has the advantage of not disturbing the colony, by needing to take a sample of bees, and is not quite as random as the "natural drop" as suggested on Beebase, which I tend to use.

CVB

This was my plan in June this year- from an earlier thread

With all the excitement during the spring honey flow and swarm season it's easy to over look varroa management.
Are folks monitoring mite levels during this short lull?
I've just VOA all my main colonies and 6 frame nucs and will be looking at the drop is a few days time. With main colonies supers were taken off before VOA then put on again approx 10+ minutes later- once I got into the rhythm it was surprisingly easy.
The plan is to estimate colony mite numbers from a single VOA and decide which need retreating to cover the brood cycle and which can survive till September!
I'm estimating 20% phoretic mites in a colony with 'lots' of sealed brood and 50% in those with 'less' sealed brood. A couple in the process of requeening will be without sealed brood so 90+% phoretic.
Any comments?

This was my rationale for whether to re-treat or not in June:

So Ive been round and checked 26 drop boards 4 days after a single vape.
Max drop was 20 mites from one colony. Rest had less than ten and some less than 5.
I had made up my mind that I would retreat any main colony with brood that had > 25 mite drop after the vape. Rational was that phoretic mites were 20% of total so with 25 phoretic mites total was 125. If double every month then by September there would be 1000 (treatment threshold).
Anyway good new is that the x4 vapes in December clearly did a good job.
Anyone else monitoring for mites at this time of year?