Varroa Alert

[The Poot]

Afternoon all,

Disturbed today after checking varroa trays after 48hrs from vaping.Very differing results.
H1. 1
H2. 0
H3. 72. 4th Nov was 10 after 24 hrs. 29th Nov was 3 after 24 hrs
H4. 31. 5. 18

Also, coincidentally perhaps, dead chucked out today was H3 = 42, H4 = 26. Others less than 6
See photos.

Dani mentioned the need to recheck varroa levels after the mild spell as bees probably continuing to raise brood.
Dani - looks like you’re right (again).

(All new queens this year-
My H1 late supercedure, H2 united colony mid June, H3 new queen mid June, H4 supercedure mating flight return Sept 4th)

 

[pargyle]

I would not get too worried about that number of dead bees on the landing board .. the colony numbers reduce dramatically over winter - as much as 60% in some cases - so if you have a colony of 40,000 at the end of the season the maths will tell you that they will have a lot of bees that will die off. With the current cold snap they won't bother removing the corpses further than the landing board - in fact it's sometimes a bit reassuring that the colony is big enough and healthy enough to continue with housekeeping duties when they can.

Varroa levels on the inspection board are not the best indication of infestation levels - the more bees in the colony the more varroa there will be .. and they die off as well. If you have something that you can use to magnify the varroa on the board you may find it interesting to have a look at the dead mites and see if any have lumps bitten off them or limbs missing. I sometimes see that with mine - sure sign that the bees are removing at least some of the varroa.

I find that some colonies where the drop on the board is highest are often those that have the least sign of infestation when I do a sugar roll.

Your OA has done it's job on the colony that may have needed a bit of assistance. Chill ....

 

[bobba]

Dani mentioned the need to recheck varroa levels after the mild spell as bees probably continuing to raise brood.

I hate you Dani.

I thought I was all done with varroa for the year after this autumns epic vape session. But I too should follow Dani's advice and check my hives.

 

[The Poot]

I would not get too worried about that number of dead bees on the landing board .. the colony numbers reduce dramatically over winter - as much as 60% in some cases - so if you have a colony of 40,000 at the end of the season the maths will tell you that they will have a lot of bees that will die off. With the current cold snap they won't bother removing the corpses further than the landing board - in fact it's sometimes a bit reassuring that the colony is big enough and healthy enough to continue with housekeeping duties when they can.

Varroa levels on the landing board are not the best indication of infestation levels - the more bees in the colony the more varroa there will be .. and they die off as well. If you have something that you can use to magnify the varroa on the board you may find it interesting to have a look at the dead mites and see if any have lumps bitten off them or limbs missing. I sometimes see that with mine - sure sign that the bees are removing at least some of the varroa.

I find that some colonies where the drop on the board is highest are often those that have the least sign of infestation when I do a sugar roll.

Your OA has done it's job on the colony that may have needed a bit of assistance. Chill ....

Much obliged for the reassurance Pargyle, cheers

 

[Erichalfbee]

I hate you Dani.

I thought I was all done with varroa for the year after this autumns epic vape session. But I too should follow Dani's advice and check my hives.

Best chance to have no brood just now as well....

 

[Ian123]

Best chance to have no brood just now as well....

I’ve normally found the lasi announcement of brood free a little premature. And not just me but an retired BI i chat with, this years been crap for ivy around me but there’s still patches with flowers on. Weather permitting bees work these and brood rearing continues in many cases. Having said that this and last year have been poor ivy wise. Ian

 

[Erichalfbee]

I’ve normally found the lasi announcement of brood free a little premature. And not just me but an retired BI i chat with, this years been crap for ivy around me but there’s still patches with flowers on. Weather permitting bees work these and brood rearing continues in many cases. Having said that this and last year have been poor ivy wise. Ian

Yes depends on temperature and forage.

 

[Ringlander]

I saw very high levels of natural mite drop on my 3 hives here in Norfolk earlier this year and treated all three in September with MAQS, which scared the heck out of me as the numbers of mites that dropped during the week the MAQS was in the hives started off at between 300 and 800 in 24 hours and dropped to 30 or so at the end of the week which still seemed high to me. The general view on this forum was the counts were very high but the MAQS had done the job and I should be glad I had used it, which made sense. I continued to check the weekly natural mite drop which further reduced to around 30 per week which at an average of 4 mites per day seemed tolerable in my limited experience. A few weeks back it started to pick up again. I vaped all three hives with Api-Bioxal a week ago when the natural daily drop was into the 20s and the immediate 24 hour drop was hive 1 168, hive 2 184 and hive 3 48. The hives were well sealed with entrance blocks fitted and the mite boards under the open mesh floor so they all got a good dose. The drop has reduced by about 40% each day thereafter ( with no additional treatment) and is now down to H1 28, H2 31 and H3 1 so pretty much where it was before the vape. I will treat them again today as these numbers are still far too high in my opinion. The questions are why are the numbers not dropping much lower and why do the drop numbers tail off so slowly with a single brief treatment like vaping which is supposed to achieve something like 95% efficiency? I would have throught it would have killed most mites more or less instantly and they would have dropped off within a few hours or a day at most, especially as there are almost no bees flying right now? I understand the MAQS drop curves better as the treatment is over a longer period, the bees were still very active and presumably it takes time to kill the mites. The bees show no signs of DWV or any other ill effects and the yield of honey this year was good. Any ideas?

 

[jenkinsbrynmair]

I would have throught it would have killed most mites more or less instantly and they would have dropped off within a few hours or a day at most,

No, it takes a few days for the OA crystals to come into contact with the mites.
And remember - if you are using the online varroa calculator to estimate mite numbers in the colony, it's formulated to work from the natural mite mortality drop so it is more than worthless used during treatment.

 

[GloryBee]

Oxalic acid works at fullpower for about 3 days then tapers off. This makes the 24hr drop basically equal to the number of phoretic mites at the time of treatment
After that its catching the emerging mites. So unless you know they are broodless or how much brood there is its tricky to predict from drops.

 

[Ringlander]

OK, that makes sense, thanks. I guess I should just keep repeating the vaping every few days until the drops are close to zero?

 

[Swarm]

Whereas the counts are evidence that treatments are working, which is good, I would be concerned with the sheer numbers, why are they so high?
People are quoting drops from hives that are higher than I get for an entire apiary after four rounds of OAV.

 

[Ringlander]

I agree. As one who's counts seem to be way above what others quote I am very concerned I am doing something wrong. I have only run one round of OAV this time around, so hopefully more goes will bring the numbers down further. Do you see the drop reduce with each round Steve? What sort of count do you get on the fourth session and what do you see as a natural drop? All thoughts appreciated!

 

[madasafish]

If your bees are robbing a near dead hive with a large scale varroa infestation, your varroa counts will be high as most mites in the dying hive will be phoretic and desperate to catch a new bee to hang out with.

No brood here- I have not looked - but we have had at least a month of grey, cold wet weather with zero bees flying. Southern England is a different world climatically.

 

[jenkinsbrynmair]

Southern England is a different world climatically.

It's a different world - if not a different universe

 

[Ringlander]

Thanks Mr (Madasa) Fish, the weathers been much the same in Norfolk, maybe a little better in that we have seen some sun but theres been no flying worth mentioning for at least two weeks now so I don't think picking up mites while robbing is the issue. Similarly I doubt there's much brood here either, they are pretty well clustered judging by the debris field on the boards and looking through the poly crownboards I can see five or six seams of bees biased to one side of the box ( the same side on all three hives...? )
Nick

 

[Ian123]

The debris can give you a clue if there’s brood cappings a or parts on the tray.

 

[Swarm]

I agree. As one who's counts seem to be way above what others quote I am very concerned I am doing something wrong. I have only run one round of OAV this time around, so hopefully more goes will bring the numbers down further. Do you see the drop reduce with each round Steve? What sort of count do you get on the fourth session and what do you see as a natural drop? All thoughts appreciated!

Natural 24hr drop is single figures, average drop on first vape 40-50, I was concerned that one colony dropped 87, best colony dropped 17 total over four vapes. Fourth vape and any drops are low single figures if any.

 

[BugsInABox]

Is it ok to tolerate a higher drop at this time of year as the 'brooded' mites will be very low or non existant?
BIAB

 

[hemo]

Unless one is treating every week , then it has to be accepted numbers will ebb and flow. Trying for a 100% kill rate isn't going to occur so just a case of keeping numbers low as possible.