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BeeBob

NZBF Bayvoral: mixed success

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I'd like advice please on next steps to address Varroa in my hives.  The thread "Bayvarol not working" under diseases has gone to sleep, so I thought I'd post here.

I'm a newbee starting with two nucs in October 2017.  A very good season and we harvested a total of 18kg from the two hives, plus some in storage to feed the hives if needed over winter.

I've been monitoring Varroa levels on a sticky board since the start and the graph below shows numbers since varroa were first detected.

I was advised to delay Bayvoral treatment as the honey flow was still on.  In hindsight, I should have put Bayvarol in in February.

The Bayvarol was installed with 4 strips per brood box on 19 March.  This led to a significant increase in Varroa counts.  There was a dip in early April (when we were on holiday), but numbers climbed again.  Then the count in the "A Team" declined to less than 100 per day.  Still too high, but way better than before.  The weaker :B Team" has remained at over 300 per day.

I did a sugar shake a couple of weeks ago. 5 in the A Team and 1 in the B Team.

The 42 day treatment period for Bayvarol finishes on 1 May.

So any advice on next steps would be appreciated.  I'm considering oxalic acid in glycerol on paper towels.

By the way, I've counted almost 20,000 varroa so far!

 

image.thumb.png.cfd05f7ced4eb6c33bdb3b62db9e3929.png

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46 minutes ago, BeeBob said:

The 42 day treatment period for Bayvarol finishes on 1 May.

I could have sworn it should be 56 days

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2 hours ago, yesbut said:

I could have sworn it should be 56 days

 

Yes agree 8 weeks for Bayvarol 

Edited by frazzledfozzle

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Thanks, I read on the Bayer website 6 weeks.

So I will hang in there....

 

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3 hours ago, BeeBob said:

hanks, I read on the Bayer website 6 weeks.

Don't worry about the website, it's what's on the NZ label that counts. 

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Same with Apivar, the packaging says 6 weeks but all the advice on here says 10 so that's what they have had, I try not to bother them too much while the treatment is in.

The 10 weeks finished today but not a hope of doing anything yet weather wise so will have to wait for the next decent day.

They have been very busy during the treatment period bringing in stores and now have a good reserve of honey for the winter so I am hopeful that in spite of my lack of experience they will be ok.

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now we are talking ..... a little bit of visual science .... how come the sudden spike on the 18 3 2018 ..... is that when youfirst tested ?

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32 minutes ago, jamesc said:

now we are talking ..... a little bit of visual science .... how come the sudden spike on the 18 3 2018 ..... is that when youfirst tested ?

Hi James

I started recording when the first mites appeared back in January (almost 23,000 mites ago!).  The spike was when I put Bayvarol in the hives.

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2 hours ago, BeeBob said:

Well things have changed for the better since my last post.

image.thumb.png.df98ecdc5e0c88af8f70a24ce98e0568.png

 

The "A Team is now at around 15 mites per day and the B Team has dropped to around 80.  "80" sounds a lot, but is a heap better than last week!

Consolidated down to 2 boxes, removed Bayvarol and added oxalic acid/glycerine towel to each hive.  All looking very good with plenty of honey capped and uncapped, quite a bit of brood capped and uncapped.  Couldn't find the queens - sneaky things.

 

I think it is highly likely that your treatment is dealing to the mites hence the decline in mite drop.

The other explanation though could be that the treatment is no longer working so mite drop has reduced.....

That is why we endeavour to do sugar shakes / alcohol washes and compare the results over time.

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5 minutes ago, CraBee said:

 

I think it is highly likely that your treatment is dealing to the mites hence the decline in mite drop.

The other explanation though could be that the treatment is no longer working so mite drop has reduced.....

That is why we endeavour to do sugar shakes / alcohol washes and compare the results over time.

 

Bayvarol certainly had an impact as can be seen by the spike.

I was concerned about your second scenario, hence my desire to put an oxalic acid / glycerol towel in the hives.  There was a mini-spike in the mite count in the A Team (blue line) three days ago that could have been a response to the OA.

You're right, in hindsight, I should have done a sugar shake when I consolidated the hives.  Can't bring myself to do an alcohol wash ..... yet!

I couldn't see either of the queens.  My father who kept 200 hives in the pre-varroa days was with me and couldn't see the sneaky queens either.  So I will check for eggs and new brood in a fortnight (there was quite a bit of capped and uncapped brood a few days ago) and then do a sugar shake.

Great resource, this forum!  

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And the trend has continued. Today just 1 mite in the A Team and 25 in the B Team.  Would like the B Team mite count to drop further but the trend is looking good.

 

image.thumb.png.a298007ca6dbcb4c895f05ccec466721.png

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Thanks for updating BeeBob, I guess the lesson here is give things time to work.

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Dave, yes some dedication - 23,000 mites later! Not sure if my wife would describe it as such.

Some interesting observations about mites in capped brood.  

Also:

- I presume that the initial peak relates to phoretic mites.

- There seem to be two peaks that may relate to the emergence of two brood cohorts.

- We were away during the period between the two peaks - hence the straight line.  I wonder what happened during that time.

- The two hives responded differently.  The B Team is somewhat quieter and had more localised brood, whereas the A Team queen laid eggs throughout the hive.

- I think mite fall is a reasonably objective low impact way to monitor mite levels.  I will do more sugar shakes next season to get a relationship between mite fall and phoretic mites.

Numbers this morning were 2 and 13 respectively. Its not as if the colonies are dying and giving low numbers.  They've both been very active during warm weather of the last week (but not in today's miserable rain).  So to answer the title of this thread - it seems like Bayvarol does work, albeit more slowly than I expected.

Yes, Alistair, patience is a beekeeping virtue!  One (among many) that I have yet to master!

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11 minutes ago, BeeBob said:

- I presume that the initial peak relates to phoretic mites.

I'd think so.

 

12 minutes ago, BeeBob said:

- There seem to be two peaks that may relate to the emergence of two brood cohorts.

Maybe. In theory brood is produced continuously, but the queen's laying may change in response to food supply, so maybe there were peaks of brood production. We can't know.

 

15 minutes ago, BeeBob said:

- The two hives responded differently.  The B Team is somewhat quieter and had more localised brood, whereas the A Team queen laid eggs throughout the hive.

- I think mite fall is a reasonably objective low impact way to monitor mite levels.

It's a good way, but closely aligned to the state of the hive rather than the state of the infestation. To make the most of it you need to be able to estimate bee population, brood coverage, and the like. Colonies are not alike either, so makes comparisons difficult. You would have no way of giving me an infestation rate or density for example, and we think 'density' is an important feature of varroa infestations.

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@BeeBob what a great bit of work. Can you expand on how you are doing it, as that is a lot of counts and i asume

you have a good system to have persisted?

The Auckland Beekeeping Club has an article this month on mite fall as a monitoring method and discussed the problem of ants carting off dead varroa - have you any problems with this or any thoughts?

Thanks.

Edited by cBank
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"You have a good system to have persisted".  

That made me chuckle! If I knew I'd be counting 23,000 individual mites, I might not have started!  I expected counts to die away much quicker than what happened.  As an aside, I expected Bayvoral to kill the mites, but I found a significant number (perhaps a few percent) on their backs still wriggling and alive - mites landing legs down always die - presumably smothered by the oil.

But my "system" worked well and was quite efficient, so happy to share.  By the way, there are many scientific papers published using mite fall as a method for monitoring mites.  This is an indication of total mite load and not the infestation rate (mites per 300 bees).  However, it is non-invasive and I believe quite consistent.

 

The photo shows the gear I use.

- One white corflute undertray that fits below the mesh bottom board.  You can see the detritus that falls from the hive, so this is good way to monitor what is going on.

- A can of cheap spray on cooking oil.  I tried vaseline as often recommended, but this is messy, is more difficult to get even, and may not hold the mites as well.  The oil also traps ants, so I do not think that ants carrying mites away is an issue.  Note that live mites are mobile and I expect them to walk off a dry board.  I use the paint roller to spread the cooking oil evenly.

- A magnifying glass to identify the mites.  Mites come in three forms: dark (sometimes alive), pale but legs visible (never alive), what appears to be just the mite carapace (this could be from bees grooming).  I just count the first two.

When I have large numbers of mites, I run the handle of the magnifying glass (or similar scribe) down the corflute and it creates a line in the hive detritus. I think it is possible to buy undertrays marked in a grid.   I try to do this parallel to the lines (and therefore frames above).  For large numbers of mites, I create up to 8 vertical strips.  I count each strip and write the numbers down.  Note that I did not subsample areas for counting as the mite distribution is not even - there are more mites in the middle (presumably below the cluster).  You need to be systematic if counting 100's of mites.

I enter the individual strip counts into Excel to do the adding.

- White plastic scraper to scrape the oil, mites and detritus off.  This goes into the garden - another advantage of oil over vaseline.

- Toilet paper to clean the residual.

- Then spray and roll and you are away. (This sounds a bit like the awaful TV ad about "Spray and wipe away".  I wish I could deal to varroa in 30 seconds!

 

I have two hives right next to each other and use the same equipment for both.  You might use a different roller and scraper for different hives if worried about AFB contamination.

 

I will continue counting perhaps twice a week to keep a tab on what is happening.  I have left the trays for two days and some say 3 days is okay.

 

Bees-47.jpg

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Bees-46.thumb.jpg.b7b70d1a5269501654026501beb7ce1f.jpg

Here is a photo of an undertray with 397 mites.  You can just see the vertical lines that demarcate the vertical counting strips.

 

This is a horrendous number of mites.  But looking at the bee behaviour coming and going in the entrance and activity/brood in the hive itself, and considering that I counted perhaps a dozen bees over summer with DWV, everything appeared rosy.  This shows how insidious varroa is.

Edited by BeeBob
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20 minutes ago, BeeBob said:

  By the way, there are many scientific papers published using mite fall as a method for monitoring mites.  

 

A thing about that. There are several reasons why natural mite drop does not always tell the full story.

 

One of those is that mites live their life cycle which is several months, get old, and eventually die. It is those old ones when they die that end up on the drop board.

 

So after an effective mite treatment when mite levels have been reduced to near zero, the mite population starts to rebuild. But in the early phases most of those mites are going to be young mites. It is only some time down the track when a lot of those mites are getting old that good numbers of them will show on the drop board.

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32 minutes ago, Alastair said:

 

A thing about that. There are several reasons why natural mite drop does not always tell the full story.

 

One of those is that mites live their life cycle which is several months, get old, and eventually die. It is those old ones when they die that end up on the drop board.

 

So after an effective mite treatment when mite levels have been reduced to near zero, the mite population starts to rebuild. But in the early phases most of those mites are going to be young mites. It is only some time down the track when a lot of those mites are getting old that good numbers of them will show on the drop board.

No good YOU trying to count mites, they're far too small.....hooohoooohaaaaaahaaaaaaaa

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@BeeBob thanks for posting all of this info it has been quite interesting to see how your mite drop numbers have progressed, it appears that Bayverol does its job over about six weeks.

 

@Rewi1973 it would be nice to to see your mite drop monitoring on here too!

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OK then @CraBee. Very much inspired by @BeeBob's mite count work shown above - I also decided to monitor daily mite drops starting in late April following regular OA vaporising treatment. Unfortunately it's a bit off topic from the original topic based on Bayvrol treatment - but hopefully still interesting to some.

 

Firstly - I'm a first year beekeeper with a lot to learn

Second - this is by no means a rigorous scientific trial so please take (or don't take) from it what you will.

 

I have two hives located together in urban North Shore in Auckland.  I took one FD honey super off each hive around mid February and then started weekly OA vaporising treatment.  From 30 April - I decided to trial OA vaporising every 3 or 4 days.  Also - sugar shakes on both hives in early April showed 5 and the other 6 mites.  The graph below records the mite drop results following treatment.  

 

North Hive - knocked down to a single FD brood box on 22 April,  3-4 frames of brood - with the rest honey. Queen continued to slow down on laying during the monitoring and bees now occupy only 7-8 frames.

 

South Hive - still two FD brood boxes - 7-8 frames of brood on 17 April.  They superseded the Queen in January and she only really started slowing up on laying a couple of weeks ago - so still have 4 nice frames of brood.  My last inspection a few days ago was the first sign of bee with DWV.

 

I have the newer Hive Dr smart bases and have been counting the mites that fall into the plastic trays that slide in underneath.

 

Results so far are:

VarroaTreatment200518.jpg.b47732771c3b401c28ce3346a491ac07.jpg

 

 

Similar findings to Randy Oliver's work in that OA has a noticeable peak on both hives in the 24 hours following treatment but then the effects of OA relatively quickly reduce from 48 hours onwards.  

 

OA has worked well at reducing mites in the North Hive (blue line) where the Queen was naturally slowing up on brood laying.  The sugar shake we did early this week was zero mites.  I have stopped OA treatment now but will continue to monitor mite drop every 2-3 days for a while.  

 

On the other hand, the stronger southern hive (red line), was struggling to bring mite levels down with OA so on the 18 May - I decided to use ApiLife VAR.  Yes - I know it is late in the season - however, we are in Auckland and daily temperatures are still around 19-20 degrees.  Hopefully still warm enough at this stage to work?  Certainly by the bees reaction during the days since the treatment went in - the smell is keeping them outside hanging around the entrance a lot longer before going in to the hive.

 

I will probably trial the brood break method next summer (begging in Feb?) and see what affect OA has during the 2-3 day period of having no capped brood in the hive.  Perhaps creating a brood break each month in late summer/early autumn for two or three months in a row and hitting with OA vaporiser each day for 3 days in a row when there is no capped brood might get on top of them?  Probably not, but worth trying - and the Queen may not appreciate be caged up for two weeks every month!

 

There are a lot more questions and "what ifs" raised than answers - so please excuse me if I don't have answers to queries.

 

 


 

 

 

 

 

 

 

 

 

 

 

 

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