Interpreting mite fall numbers after OA Vape

[bobba]

I have 2 hives and have been vaping them at 5-day intervals.

One hive has had 3 vapes and the other 2 vapes with the 3rd due on (30/9/2019).

The 48h drop counts for hive 2 are:

V1 = 20
V2 = 15
V3 = 15

The 48h drops on my original hive so are:

V1 = 1000+
V2 = 500 ish

Both hives were last treated on 23/07/2019, The Original hive had 20 @ 48h. But was unable to count for hive 1 as it was a fresh swarm on solid floor.

Firstly, I had been under the belief that 3 vapes 5 days apart and the mites would be pretty much eradicated. However, I have seen it mentioned that I may need a 4th or even 5th vape. Any advise on how to tell when I have killed enough would be appreciated?

Secondly, when I did the first vapes on 23/07/2019, the original hive had just swarmed and was broodless. (was 2nd swarm so brood was depleted). I assumed the vape would kill a high %, so when only 20 dropped at 48h, I though job done. Should I have given a 2nd/3rd vape?

I know about the life cycle of the mites, but am still shocked that numbers could have climbed so fast in about 70 days. Especially considering the hive has been broodless for much of this time. Maybe they have been robbing an infested hive!

I do have some MAQS to hand, should I use them?

Any advice and banter welcome. Thanks in advance.

 

[Erichalfbee]

How are you vaping?
If under the floor then are you adding a little more Apibioxal?
Vaping a hive with no brood will get 98/99% of the mites. So if truly broodless then one vape is sufficient.
It’s useful to do another a month later just to make sure the bees have not been reinvested by drifting diseased bees or by robbing
As for estimating what is in the hive to start with you need a 24 hour count multiplied by 5
I always do an accelerated drop a month after my last vape to check as before
I’m happy with a 24 hr drop of 5 at the end of treatment. Any colony with mites still dropping in numbers after 5 vapes gets Apivar
I’ve had bad experiences with MAQS and would never use it again especially when I can’t replace the queen

Your second hive needs Apivar now.

 

[jenkinsbrynmair]

must have taken you ages to count all those.
Or are you using one of the mite drop calculators available? which BTW is useless for counting after treatment as they are designed as a ready reckoner to estimate live mites in the colony by counting mites on the tray during natural (untreated) mortality

 

[madasafish]

"Firstly, I had been under the belief that 3 vapes 5 days apart and the mites would be pretty much eradicated. However, I have seen it mentioned that I may need a 4th or even 5th vape. Any advise on how to tell when I have killed enough would be appreciated?"



Err:
Vape 1 kills phoretic mites
Between V 1 and V2 more mites emerge from capped brood and some enter brood being capped.
Vape 2 kills more phoretic mites..The brood that was capped around date of Vape 1 is still capped and contains more mites.
Between V2 and V3 more but far fewer mites emerge from capped brood and some enter brood being capped.

SO there are still some mites in capped brood after V3..





Your mite load appears very heavy.. so V3 may kill 100 mites.. but you could still have a hundred or more. in capped brood..




Edit I used MAQS for the first time this year on Lang jumbos with supers - as per the instructions.. Seven hives and six nucs.. no problems at all.

As UK National brood boxes are so small., I would halve the dose for them..(I use a half dose on jumbo 5 frame nucs - no supers - and they were fine.. They contain as many bees as a National BBox.)

MAQs was developed for Langstroths. Many US beeks use double mediums which are twice size of a National. Most Nationals are at best Brood and half.. v small.

 

[gmonag]

As I understand it, 4 OA vapes at 4-day intervals works like this:

Vape 1 kills nearly all (98%+) phoretic mites
During the next 4 days, mites emerge from brood and remain phoretic for 4-5 days
Vape 2 kills nearly all phoretic mites. No more can enter brood.
During the next 4 days, mites emerge from brood and remain phoretic for 4-5 days
Vape 3 kills nearly all phoretic mites
During the next 4 days, mites emerge from brood and remain phoretic for 4-5 days
Vape 4 kills nearly all remaining phoretic mites

There will be approx 20-30% of the initial total of mites in the hive drop each time.

That completes one worker brood cycle and no more mites are in the brood.
If there are drone brood you need more vapes but there should not be any at this time of year,

 

[jenkinsbrynmair]

As I understand it, 4 OA vapes at 4-day intervals works like this:

Vape 1 kills nearly all (98%+) phoretic mites
During the next 4 days, mites emerge from brood and remain phoretic for 4-5 days
Vape 2 kills nearly all phoretic mites. No more can enter brood.
During the next 4 days, mites emerge from brood and remain phoretic for 4-5 days
Vape 3 kills nearly all phoretic mites
During the next 4 days, mites emerge from brood and remain phoretic for 4-5 days
Vape 4 kills nearly all remaining phoretic mites

There will be approx 20-30% of the initial total of mites in the hive drop each time.

That completes one worker brood cycle and no more mites are in the brood.
If there are drone brood you need more vapes but there should not be any at this time of year,

 

[SDM]

Oxalic acid vapour is at close to peak efficiency for 72hrs after treatment. No mites emerging between vapes should have time to enter brood.

 

[bobba]

"How are you vaping?"

With a pan vape, one and a bit scoops for the original hive as its brood and a 1/2. And 1 scoop for hive one as its single brood.

https://www.ebay.co.uk/itm/Oxalic-A...960051?hash=item3f49415cf3:g:OKcAAOSwxN5WU3aR

I power it with a jump starter and vape from below the mesh floor. I can sit this particular vape on the correx board without melting it.

"must have taken you ages to count all those"

I count a lot insects in the day job - I am surprisingly proficient after 10 years practice.

And thanks for the useful advise. It looks like I will be switching to the 4x4 method.

 

[Erichalfbee]

And thanks for the useful advise. It looks like I will be switching to the 4x4 method.

Make your last and any subsequent intervals 4 days
So vape days 1/6/11 and 15

 

[Swarm]

What worries me are the mite numbers I see people posting. I was concerned about a drop of 80+ after first vape, I've never seen numbers like that.

 

[Erichalfbee]

What worries me are the mite numbers I see people posting. I was concerned about a drop of 80+ after first vape, I've never seen numbers like that.

I’ve had first drops of about 70/80 on one colony 50 on another and less than 10 on three.
The only time I’ve seen a drop like one of bobba’s is that colony that dropped nigh on 8k mites a few years back.
I’d be quite worried too.

 

[The Poot in Somerset]

I've had odd varroa dealings this year. Three hives equally spaced. On checking in July - hives 1 & 3 minimal drop - no 2 - hundreds. After vaping.

I vaped no2 several times and have got them sorted.
In early September vaped 1 & 3 and had shocking numbers of mites.
Have vaped four times more since then and I have the mites on the run but still dropping more than I like.
A couple more vapes should do it.

It certainly pays to do regular checks as its scary how quickly they multiply in a robust colony.

 

[gmonag]

I think it is more than just the mites reproducing. That will "only" double their numbers every 3 weeks. I suspect the bees are robbing (feral?) hives that are crashing and bringing home their mites.

 

[bobba]

gmonag - I suspect the same. As mentioned this hive was also broodless for a long time. It also tried to rob hive-1, lucky I intervened. But it may have robbed some other hive.

"Make your last and any subsequent intervals 4 days So vape days 1/6/11 and 15 " Thanks Erichalfbee - that's what I was intending after the advice, but its nice to have instructions in black and white.

The guy I bought the bees from said he does one vape per year on the shortest day of the year - job done. Apparently that was the only treatment he used. I guessing he may monitor and treat more if necessary. I may ping him a text tmr and see what he advises.

 

[enrico]

I have had huge mite drops this year. Done second vape and one more to go. Just beginning to see a reduction thank goodness.
E

 

[jenkinsbrynmair]

The guy I bought the bees from said he does one vape per year on the shortest day of the year - job done.

so depending more on witchcraft than any scientific fact.

 

[SDM]

so depending more on witchcraft than any scientific fact.

There's usually, a whole heap of truth in witchcraft .
Don't knock it.

 

[Erichalfbee]

The guy I bought the bees from said he does one vape per year on the shortest day of the year - job done. Apparently that was the only treatment he used. I guessing he may monitor and treat more if necessary. I may ping him a text tmr and see what he advises.

But is that ALL he does?
If your bees have significant hygienic traits then it might just work provided there is absolutely no brood. After all, that was the basis behind LASI queens wasn’t it. It’s what the Sussex lot we’re working at and advocated till their hygienic colonies got EFB.
I always thought that treating in mid winter only left your most important bees with the highest viral load of the year, but who am I to argue with a professor of Apiculture?

One thing’s for sure, bobba, if you had left that severely infested colony till December you would have saved yourself a lot of work.

 

[jenkinsbrynmair]

I always thought that treating in mid winter only left your most important bees with the highest viral load of the year, but who am I to argue with a professor of Apiculture?

I once sailed with a Master Mariner, who was also a qualified deep water yacht skipper - didn't stop him totally ignoring the buoyage coming out of James Watt dock in Greenock and dumping a newly refitted Customs Cutter on the rocks.

One of the more useful LASI findings was that the most likely time to find the colony broodless was late November/early December, so that knocks the 'shortest day' mantra fairly and squarely into the beekeeping myths and magic box.

 

[Erichalfbee]

One of the more useful LASI findings was that the most likely time to find the colony broodless was late November/early December, so that knocks the 'shortest day' mantra fairly and squarely into the beekeeping myths and magic box.

In Sussex maybe.
I’ve never taken my colonies apart between October and mid March to check
I always considered the “treat the bees Christmas Day” a ploy to get away from family pandemonium for a while.