2023 curious how everyone is doing with varroa

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8
2
New zealand
Experience
Semi Commercial
Hi! Just wondering how people are getting on with varroa this autumn about to head into winter..??
by now I try not to open the hives unless necessary..just topping up with frames of honey for winter. But I have noticed some dwv outside some hives..one more than others..but still others have some.. apivar strips have now been in 6 weeks ..and I did a knock down treatment of formic acid 7 days b4 that went in.. so today I looked inside the hive with most dwv outside the hive..also some otherwise healthy looking bees in grass outside that look to b sign of varroa issues..
Inside the hive..the hive generally looks good..good amount of nice healthy bees..brood looks ok..but! There is the odd cell that the brood one here or there..not many but they are there where the brood has died from my guess varroa and I opened a couple of capped cells and found mites on the almost ready to emerge bees.. I'm not sure if I should b waiting and letting the apivar run its full 8 week course before considering alternatives?? Is only 2 more weeks..I feel like there shouldn't b that many mites after 6 weeks of treatment has already passed.?? Will try inspect couple more hives 2mro to see if they are similar, better or worse...but can't take long as robbing is high risk.. im just wondering others experience, opinions and advice. thanks team 😊
 
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maungaturoto
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i don't think you can do much more.
i would jar test to see what level they are at.
otherwise just let apivar do the job and hope the bees recover.

the cause of it? either a poor spring treatment and mites have increased and gained high numbers before you could treat.
or there has been some hives fail nearby and you got some mite drift. plenty of abandoned hives around at the moment, or people shortcutting hive treatments.
 
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8
2
New zealand
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Semi Commercial
i don't think you can do much more.
i would jar test to see what level they are at.
otherwise just let apivar do the job and hope the bees recover.

the cause of it? either a poor spring treatment and mites have increased and gained high numbers before you could treat.
or there has been some hives fail nearby and you got some mite drift. plenty of abandoned hives around at the moment, or people shortcutting hive treatments.
 
8
2
New zealand
Experience
Semi Commercial
Thanks, yea.. guess i was just wondering if others were having doubts or issues with apivar or any signs of resistance .

Hives had synthetic strips spring. Oxalic during manuka. Formic straight after flow and apivar 7 days after that.. and no known hives nearby at this time.. hives all strong and healthy, no noticeable mite infestations.. until now. Crazy going from 2 treatments a year and next to no varroa...to almost all year round treatment and still varroa 😵‍💫🙈🙄 anywho thanks for yr reply
 
8,918
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maungaturoto
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Hives had synthetic strips spring.
which ones?

s i was just wondering if others were having doubts or issues with apivar or any signs of resistance .
while not impossible, its highly unlikely.
however its a little slow, hence the 10 weeks treatment time instead of the usual 8 week. that can catch people out with high mite load.

Oxalic during manuka. Formic straight after flow
but it depends on how it was done. if not done well it may have done nothing.
if its done well then there is no way you should be having mite problems unless you have huge mite invasion due to an entire site failing nearby.

the other possibility is that the spring strips didn't work, the oxalic and formic didn't do much, which would certainly give you high mite loads.
trouble with most organic methods is that they tend to have lower effectiveness and more variability even when done well. then add in that there is many poor methods doing the rounds, you can end up with widely different results.
it would pay to post up your methods of oxalic and formic, and make sure its a viable method. i havn't done formic but i know a few here have done it.
 

frazzledfozzle

Founder Member
9,130
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Nelson/Tasman District
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for the first time ever we are seeing problems.

I was feeling quite smug there until we got nervous with most everyone else saying they had issues so we thought we should take a look.

3 mites dropping on an ether roll but bottom board chooks with dead mites.
quite a few dead hives.
we are using Bayvarol but they went in very late not finishing the last site until around the 20th March which is a good Month later than they should have gone in.

So not sure if our problems stem from late treatment with high mite load infesting the brood which has emerged recently and probably very compromised or if we have other problems

The fact there’s a heap of mites on the floor make me feel like it’s a late treatment problem But I don’t know.
 

Alastair

Founder Member
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8,823
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Auckland
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apivar strips have now been in 6 weeks

That means the treatment went in later than it should have by a good month.

In these cases if using Apivar people will still sometimes see DWV late into the treatment. It takes a while to wind down mite numbers.

Sometimes even after the treatment. I think the after treatment DWV in a hive that was badly infested can be a lag that the viruses can still linger a while even after the mites are gone.

My advice re Apivar - leave it in 10 weeks, don't store it in sun or the cab of your truck where it will get hot, and place it correctly in the hive, ie, central in the brood.
 
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Alastair

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we are using Bayvarol but they went in very late not finishing the last site until around the 20th March which is a good Month later than they should have gone in.

I remember back in the day you could go to a hive crawling with mites, dead brood, wingless bees, drop 4 bayvarol strips in, and in 3 weeks it would be clean.

Not so any more, there are problems with bayvarol. Or perhaps not the bayvarol, but the mites.
 
8,918
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maungaturoto
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I think the after treatment DWV in a hive that was badly infested can be a lag that the viruses can still linger a while even after the mites are gone.
yes, virus still go one for quite some time and can still kill off a hive well after mites are gone.

I remember back in the day you could go to a hive crawling with mites, dead brood, wingless bees, drop 4 bayvarol strips in, and in 3 weeks it would be clean.
yes. that was a long time ago. 20-30 mites /300 bees and you might start seeing issues, now its ~7/300 and its downhill from there.
the effects last much longer even after the mites are gone. it takes the bees a long time to shake off that virus load.
 
43
29
Dunedin
Experience
Hobbyist
Phil Lester's group did some work on sensitivity of bees to Flumethrin, published only very recently.....

"the concentration of Flumethrin required to kill 50% of mites (LC50) was 156 μg/g, which was 13 times higher than the adjusted LC50 value of 12 μg/g observed in a previous trial conducted in New Zealand in 2003. This suggests that Varroa resistance to flumethrin is developing in New Zealand."

Ref.:
Are increasing honey bee colony losses attributed to Varroa destructor in New Zealand driven by miticide resistance?
Rose Ann McGruddy, Mariana Bulgarella, Antoine Felden, James William Baty, John Haywood, Philip Stahlmann-Brown, Philip J Lester
https://www.researchgate.net/public..._in_New_Zealand_driven_by_miticide_resistance
 
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272
320
Gisborne Tairawhiti
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Phil also spoke about this work at last year's conference - where he took pains to say that the work was *not* to say that the synthetic pyrethroid treatments (Bayvarol and Apistan) were no longer working. As such, I believe that the title of the manuscript is unfortunate.
I should add that the manuscript is a pre-print and has not been peer-reviewed.

Part of the issue with the manuscript is that while varroa was reported to need higher levels of flumethrin, they required much *less* amitraz - about 1/10th the amount. This is disregarded somewhat as earlier study errors.
 

Jhah

BOP Club
11
6
kawerau
Experience
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Thanks, yea.. guess i was just wondering if others were having doubts or issues with apivar or any signs of resistance .

Hives had synthetic strips spring. Oxalic during manuka. Formic straight after flow and apivar 7 days after that.. and no known hives nearby at this time.. hives all strong and healthy, no noticeable mite infestations.. until now. Crazy going from 2 treatments a year and next to no varroa...to almost all year round treatment and still varroa 😵‍💫🙈🙄 anywho thanks for yr reply
My hives continuously get reinfected lots of beekeepers around here it only takes one colony to collapse nearby (within so many kilometers I think it was 7).Bees are like humans in many respects one being if theres free honey down the road ready made,they will go for it.
 


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