Treating bees with Vaporised Oxalic acid when their not all home.

[Plenty of honey]

Cant find an answer to this thats bugging me. If you treat early morning or late evening when there not all at home and some are still flying, will those that might be starting to foraging or those on their last flights of the day, in reality, come in to contact with as much vaporised oxalic acid as others still in the nest / Colonie?
Just extends my treatment time if i was confident that a few flying would not really matter??

 

[JWF]

My understanding is that the OA particles get distributed throughout the hive, which ensures that the majority of bees are exposed to it, including those not in the hive at the time of treatment.

 

[Erichalfbee]

As above.
I like to treat when they've stopped flying as I can't cope with all the bees trying to get in.

 

[jenkinsbrynmair]

It's not the 'vapour' that gets the mites, it's the de-sublimated crystals tht land on the bees afterwards - there'll be plenty in the hive to share amongst the absent bees by contact.

 

[Cussword]

It's not the 'vapour' that gets the mites, it's the de-sublimated crystals tht land on the bees afterwards - there'll be plenty in the hive to share amongst the absent bees by contact.

 

[madasafish]

If the vapour was the only active ingredient, you would get one mite fall after treatment. You don't. You get mite falls for days. Therefore vapour is not the active ingredient.

 

[Plenty of honey]

If the vapour was the only active ingredient, you would get one mite fall after treatment. You don't. You get mite falls for days. Therefore vapour is not the active ingredient.

Yes that does make sense, as we see the drop over the following few days.
Thank you all!!
Until this year, I've only ever treated in November and January, when you get plenty of time early morning, when its light enough to see what your doing, but cold enough so their all home!!
That does answer my question!!

 

[charlievictorbravo]

Plus, of course, the mites are much more likely to be on the nurse bees in the hive rather than on the foragers that leave the hive regularly. A mite on a forager might well miss its opportunity to reproduce by being out of the hive when cells are being sealed.

My hive that was treated with an oxalic-based product four times is still dropping too many mites. It has dropped 95% of the mites in the first 12 days after the final treatment but it's still dropping over 15 a day 21 days after treatment.

CVB

 

[Eyeman]

My hive that was treated with an oxalic-based product four times is still dropping too many mites. It has dropped 95% of the mites in the first 12 days after the final treatment but it's still dropping over 15 a day 21 days after treatment.

Its useful to get feedback from someone who monitors the response to treatment rather than those that cross their fingers and pray.
What is it do you think that you are doing wrong? Everybody seems to think OAV is the bees knees when it comes to treating when brood is around.

 

[madasafish]

Its useful to get feedback from someone who monitors the response to treatment rather than those that cross their fingers and pray.
What is it do you think that you are doing wrong? Everybody seems to think OAV is the bees knees when it comes to treating when brood is around.

Capped brood is unaffected by OA. The mites are only exposed when the bees emerge.. Do the sums.

Mine drop varying quantities ... you can see the effect of emerging brood by mite drops in lines with the combs in bad cases.... (photos are lousy so not shown)

My worst has dropped over 500 mites , was 40/day now 20 odd..

 

[Eyeman]

Capped brood is unaffected by OA. The mites are only exposed when the bees emerge.. Do the sums.

The hope is that OAV has a prolonged effect which catches new mites that emerge.
What if the prolonged 'drop' is simply due to a staggered death of the original phoretic mites?
I along with others hope that repeated OAV works. It's worrying that some of those monitoring mite levels don't seem to be seeing mites dropping below sub economic thresholds.

 

[Erichalfbee]

I monitor post vape and see immature mites on the board

 

[Nige.Coll]

It's not a problem, the varroa hang out on mainly nurse bees anyway. They can apparently tell the difference due to the smell of the bee.

 

[The Drone Ranger]

An API life var treatment takes seconds to apply £3.00
To get the same effect on varroa you would be dragging your vapourising gear to the hive 3 or 4 times
Vapourising in Winter is the best treatment but you would need to have a lot of hives or a lot of spare time to choose Oxalic in Autumn



Sent from my LIFETAB_S1034X using Tapatalk

 

[madasafish]

The hope is that OAV has a prolonged effect which catches new mites that emerge.
What if the prolonged 'drop' is simply due to a staggered death of the original phoretic mites?
I along with others hope that repeated OAV works. It's worrying that some of those monitoring mite levels don't seem to be seeing mites dropping below sub economic thresholds.

Sorry but what is " sub economic thresholds."?

I assume you mean the natural drop level of 2-3 /day.


If so, apples and pears.
Without treating you may see any level of natural drop - and a hive may be very badly infested and the mite drop still be low. It is notoriously wrong as an indicator.

If you are using OA vaping - efficiency up to 97% let's say 80% as an example = and you have 100 phoretic mites in the hive and 40 mites a day emerging from brood cells a day - then the mite fall would look like this:
(NOTE: this is an example only)

Start of day 1
Phoretic mites: 100
Drop :80% =80
Mites left = 20 + emerging 40 =60

Start of day 2.
Phoretic mites: 60
Drop :80% =48
Mites left = 12 + emerging 40 =52

Start of Day 3
Phoretic mites: 52
Drop :80% =42
Mites left = 10 + emerging 40 =50

Start of Day 4
Phoretic mites: 50
Drop :80% =40
Mites left = 10 + emerging 40 =50



And so on.

As a badly infested hive will have LOTS of mites within the brood cells, you can treat a hive with brood for weeks before you will see any huge fall. That will happen when the phoretic mites start declining in numbers and the mites entering brood cells fall.

Capped brood takes 12 days to emerge. Varroa mites enter just before capping..So for 12 days from treatment start , you will see NO reductions in mite fall from emerging brood..

Some time or other, I'll set up a spreadsheet to play with the numbers..

I see lots of dead immature mites on my hive with bad infestation..

 

[For want of a better word]

I vaporise OA as I take the last of the filled supers off.
Takes 2 hours for 10 colonies... and easy once a routine is in place.
Smaller deep cycle batteries seem to cut down the carrying problem... and can be used on the electric fences too ( So SWMBO sees the benefit too!)
8 days later as I set up to add Apiguard I Vaporise again

If everyone with bees did this... and killed off all the infested feral living colonies... and ceased the habit of importing infested bees into the UK...

Could we be Varroa free in 5 years?

Yeghes da

 

[charlievictorbravo]

As a badly infested hive will have LOTS of mites within the brood cells, you can treat a hive with brood for weeks before you will see any huge fall. That will happen when the phoretic mites start declining in numbers and the mites entering brood cells fall.

Capped brood takes 12 days to emerge. Varroa mites enter just before capping..So for 12 days from treatment start , you will see NO reductions in mite fall from emerging brood..

Some time or other, I'll set up a spreadsheet to play with the numbers..

I see lots of dead immature mites on my hive with bad infestation..

MAAF

I note that you're going to look in some detail at the mathematics of mite drop after treatment, using a spreadsheet.

I have some data from my recent treatments that might help/inform your investigation.

The background to these data is that I have 3 colonies, two have low number of mites, but one had crept up over the summer to between 30 and 40 a day which I considered to be too high. I decided to do the 3 x 5 day treatments (2.5 gms OA-based product vaped in home-made equipment) but after the third treatment, I was still getting what I thought were high drops. I did a 4th treatment and the same thing happened. I did a 5th treatment and I thought I had cracked it but in the last 3 days, the numbers of mites dropped has started to creep up again - yesterday drop was 30, 22 days after last treatment, up from a low of 8 on day 18.

I think I will have to use a Thymol-based treatment on these bees but am reluctant to keep putting chemicals into the hive. However, needs must, when the devil drives.

If you want this data, pm me with your email address and I'll send it to you. I cannot attach an Excel file to this message.

Colin

 

[Erichalfbee]

Any way....never mind residual effect.
let's presume most of the phoretic mites get hit when you vape?
New mites emerge the day after you vape...
How long before they themselves mature and pop into brood, rendering themselves inaccessible?
How long before the next vape?

 

[jenkinsbrynmair]

five days

 

[Erichalfbee]

Exactly!