Will mites become resistant to oxalic acid?

[Beekeeperscottish]

Many people would disagree quite vociferously with your approach; it's a "debate" that recurs on this forum and others. But I lean much more towards your view than I do towards the "keep zapping them till their gone" contingent. It's just that it gets wearisome seeing the upset it causes when people with strong views get hooked into this debate.

That’s why I carefully worded my comment
Thanks for the reply, it’s nice to talk about something that doesn’t end up in an argument.

 

[Hachi]

Many people would disagree quite vociferously with your approach; it's a "debate" that recurs on this forum and others. But I lean much more towards your view than I do towards the "keep zapping them till their gone" contingent. It's just that it gets wearisome seeing the upset it causes when people with strong views get hooked into this debate.

For me, I have my winter regime that is now seeing my colonies survive the winter. I'm not bragging just stating a fact of last year after years of trying.

This is where I have the problem, It is recognised, a naturally occurring "heavy" mite drop is not a reliable method of assessing accurate mite load [I think alcohol wash is purported to be the most accurate]. Sure it can be used as a indicator that you need to treat tho.

If a hive has a heavy mite load such that it results or contributes to the demise of that colony over winter, when the colony is at its most vulnerable, the root cause of the colony dying out is largely not determined. More often than not the beek consoles themselves with "it just died out winter losses"; "it happens to the best of us"; the BBKA survey [of winter losses which is pretty much useless statistically] says so. So what, we don't know what we don't know. But to then not consider the impact a heavy mite load probably had on a colony in its demise fails to help our understanding of the mite problem on a potentially large scale. This then either directly or in directly risks us coming to the conclusion we have mite resistant bees whereas the science tells a different story.

 

[madasafish]

Others here and I have seen colonies drop HUGE (think hundreds ) of mites daily. Treated with OA vaping and after 3-4 goes 5 days apart still dropping hundreds. Only explanation: robbing a failing badly infested colony left to die. (Happened in Autumn in my case so highly likely: I have seen a colony collapse from very strong with five supers in July to half a box of bees by September - all due to very high varroa loads)

Nothing to do with the colony's resistance to mites (or otherwise) but bees just being bees.
SO this argument in my eyes is so easily ignoring the effect of "leave alone" beekeeping - which is NOT "not treating" but a lot worse. I have seen it a lot round here: people keeping bees who have no clue. They then ask for help ..and guess what?: 9 out of 10 times their colonies are riddled with varroa and they collapse. And the beekeepers did nothing - because they were pig ignorant. And still are as they don't want. to learn and then change what they do.

I have another one just now. (nice people but have no clue). Ask me for queens - which I have - before they actually know they are Q-. I then go back to basics and check with a test frame - IF the colony is not too far gone. But little point in wasting time on a fatally weak colony at this time of year. By the time treatments have been given - before uniting - they will be all dead. (and no point in uniting when riddled with varroa and DWV)

Excuse the rant.

 

[Nige.Coll]

As i understand it the Oxalic Acid works in a few ways.
Because varroa have wet mouthparts and wet sticky pads on their feet those are the two primary ways the OA kills the mites, when exposed to moisture it becomes acid and burns their feet and mouthparts.
This kills the mites by either blood poisoning or starvation, you'll see a drop for 3 days after oav as a rule. If the sticky pads are damaged they cannot cling to the bee and damaged mouthparts they cannot feed.
Trickling OA has a slower but similar effect.
Resistance to OAV is unlikely but not impossible I guess nature always has a way.
I have noticed that since neonics have been banned there has been a huge reduction in mite numbers in my colonies, this year beginners uncapping drones found no mites at the training apiary. They are there but in lower numbers than when neonics was used.
Neonics kills ants and termites by supressing the grooming instinct, found this on a paper that has now vanished from the internet for some reason the link goes nowhere now. Maybe now with the neonics gone the bees are grooming more and that is helping to manage the mite numbers. Who knows. I know mites are much less of a problem than they were a few years ago but i have also changed all my queens since then too.

 

[Nige.Coll]

Others here and I have seen colonies drop HUGE (think hundreds ) of mites daily. Treated with OA vaping and after 3-4 goes 5 days apart still dropping hundreds. Only explanation: robbing a failing badly infested colony left to die. (Happened in Autumn in my case so highly likely: I have seen a colony collapse from very strong with five supers in July to half a box of bees by September - all due to very high varroa loads)

Some of that can be others using Apiguard. It is a repellant that's why it should be used on all colonies at the same time.

 

[Apinor]

Hello from Norway.
So fare nobody mention the different between oxalic acid and the acaricides making resistence. It is very important to see the differences to understand the effect of oxalic acid. Oxalic acid is an acid which can not be directly compared with the acaricides. Varroa forms resistance against the acaricides just because they are designed in a way making varroa able to make changes over time and survive. Oxalic acid is very acidifying in the solution used for dripping. If oxalic acid didn`t give an acidfying effect, it would not give any effect. To make resistence against something that etches on the surface outside of the body or inside, is more or less impossible for the varroa to form resistance to. We see the same by the way the food industries are cleaned. As long as you are using cleaning agents and routines alternating between agents based on caustic soda and acids which attach the surfaces, resistance is not formed because it is the substances' ability to corrode/etch the bacteria's surface that kills the organisms. The Japanese have used oxalic acid for varroa treatment since the 1960s without any evidence of resistance, and as long as oxalic acid has an acid effect, the effect will be very demanding for the varroa to cope with.
On the other hand, we have seen a deterioration that worries us. One treatment in the fall as only treatment/action against varroa is not enough to prevent break down any longer. I myself have been using oxalic 20 years. The first 15 years the only treatment was a drippeling in November, nothing else to be done. But I can see a build up of varroa in July/August which kills hives during winter. Now I make tests with two treatments, one in start of October and one in the start of December. By drone frame inspections in summer after two treatments, the number of varroa is very limited and makes no harm so fare. When the detected varroa is so low, I consider whether two treatments every two years would perhaps have worked. Mixing ratio of solution: Oxalic acid dihydrate 150g, water 2 liter and sugar 2kg. Used between the frames: 3,5ml hitting the bees.
Why is one treatment not enough anymore? Do the number of varroa increase due to reduced effect? No, the number of varroa falling down by one treatment is more or less stable, but it is likely to believe the virus spread between the bees are more dangerous. Of that reason it is important to get rid of as many varroa as possible early in the autumn in order to reduce the number of mites that spread dangerous viruses before it is too late. The climate changes is also starting to be challenging. The bees are breeding to November which we rarely experienced before, and with the breeding, more varroa. I am very interested in getting the experiences of others who fight varroa in a similar way as described here.

 

[Erichalfbee]

Hello @Apinor
Welcome to the forum

 

[user 20297]

Hello from Norway.
So fare nobody mention the different between oxalic acid and the acaricides making resistence. It is very important to see the differences to understand the effect of oxalic acid. Oxalic acid is an acid which can not be directly compared with the acaricides. Varroa forms resistance against the acaricides just because they are designed in a way making varroa able to make changes over time and survive. Oxalic acid is very acidifying in the solution used for dripping. If oxalic acid didn`t give an acidfying effect, it would not give any effect. To make resistence against something that etches on the surface outside of the body or inside, is more or less impossible for the varroa to form resistance to. We see the same by the way the food industries are cleaned. As long as you are using cleaning agents and routines alternating between agents based on caustic soda and acids which attach the surfaces, resistance is not formed because it is the substances' ability to corrode/etch the bacteria's surface that kills the organisms. The Japanese have used oxalic acid for varroa treatment since the 1960s without any evidence of resistance, and as long as oxalic acid has an acid effect, the effect will be very demanding for the varroa to cope with.
On the other hand, we have seen a deterioration that worries us. One treatment in the fall as only treatment/action against varroa is not enough to prevent break down any longer. I myself have been using oxalic 20 years. The first 15 years the only treatment was a drippeling in November, nothing else to be done. But I can see a build up of varroa in July/August which kills hives during winter. Now I make tests with two treatments, one in start of October and one in the start of December. By drone frame inspections in summer after two treatments, the number of varroa is very limited and makes no harm so fare. When the detected varroa is so low, I consider whether two treatments every two years would perhaps have worked. Mixing ratio of solution: Oxalic acid dihydrate 150g, water 2 liter and sugar 2kg. Used between the frames: 3,5ml hitting the bees.
Why is one treatment not enough anymore? Do the number of varroa increase due to reduced effect? No, the number of varroa falling down by one treatment is more or less stable, but it is likely to believe the virus spread between the bees are more dangerous. Of that reason it is important to get rid of as many varroa as possible early in the autumn in order to reduce the number of mites that spread dangerous viruses before it is too late. The climate changes is also starting to be challenging. The bees are breeding to November which we rarely experienced before, and with the breeding, more varroa. I am very interested in getting the experiences of others who fight varroa in a similar way as described here.

From what you say, maybe varroa near you are becoming "resistant" to varroa.

It does seem an open and shut case that a strong acid is impossible to resist, if it covers the body of a mite. Since it seems to be recommended that several applications of oxalic are made, it seems obvious that some mites are avoiding being killed. That is probably because of behavioural reasons, by either accidentally or intentionally avoiding the worst of the acid. Certain parts of the hive may not be well covered by the sublimate, or bees engaged in certain tasks, (foraging being the obvious one), may miss being treated. Whatever the reasons for the survival of some "treated " mites, and regardless of how minor the factors that help towards survival may be, the behaviours or circumstances that promoted survival will slowly become consolidated within the mite population.

It's "academic" for many people who see all this as peripheral to the "fight" against the mite, but it is surprising to read that maybe oxalic acid may gradually lose some of its efficacy.

 

[jenkinsbrynmair]

Since it seems to be recommended that several applications of oxalic are made, it seems obvious that some mites are avoiding being killed. That is probably because of behavioural reasons, by either accidentally or intentionally avoiding the worst of the acid

not really - the multiple applications are to catch the mites already in with the capped brood (part of their life cycle looooong before OQA application became the norm, it goes the same for any other treatment), you need them to emerge with the bees before the OA will get them

 

[user 20297]

not really - the multiple applications are to catch the mites already in with the capped brood (part of their life cycle looooong before OQA application became the norm, it goes the same for any other treatment), you need them to emerge with the bees before the OA will get them

Do you think most people ever get to the point where they have eliminated every mite from that season's line?

 

[jenkinsbrynmair]

Certain parts of the hive may not be well covered by the sublimate, or bees engaged in certain tasks, (foraging being the obvious one)

No, not obvious, the OA microcrystals circulate around the hive for a few days after application, so the foragers will get a dose when they get back to the hive and mingle with the others.

 

[jenkinsbrynmair]

Do you think most people ever get to the point where they have eliminated every mite from that season's line?

no - that's just a pipe dream

 

[Mint Bee]

Maybe I am getting the wrong end of the stick with this post but it’s all about varroa becoming resistant to chemicals? How about bees that can survive and thrive without the use of chemicals? Have we not learned anything? Take antibiotics, we are now told to drink plenty of water and paracetamol for a cold not antibiotics as “we” have become immune to antibiotics, mostly due to not finishing a course of tablets or just a general immunity. (Not taking sides or want an argument) Take COVID 19 vaccinated v unvaccinated.

colds (mostly) are caused by viruses. antibiotics target microbial organisms - not viruses. patients demanding some form of treatment from GP's lead to poorly focused prescription of antibiotics from GP's that has lead to increased resistance to antibiotics from microbial organisms. nothing new there, been going on for decades. we have not become immune to the treatment - viruses were never impacted. other than that perfected valid statement

 

[Antipodes]

From what you say, maybe varroa near you are becoming "resistant" to varroa.

It does seem an open and shut case that a strong acid is impossible to resist, if it covers the body of a mite. Since it seems to be recommended that several applications of oxalic are made, it seems obvious that some mites are avoiding being killed. That is probably because of behavioural reasons, by either accidentally or intentionally avoiding the worst of the acid. Certain parts of the hive may not be well covered by the sublimate, or bees engaged in certain tasks, (foraging being the obvious one), may miss being treated. Whatever the reasons for the survival of some "treated " mites, and regardless of how minor the factors that help towards survival may be, the behaviours or circumstances that promoted survival will slowly become consolidated within the mite population.

It's "academic" for many people who see all this as peripheral to the "fight" against the mite, but it is surprising to read that maybe oxalic acid may gradually lose some of its efficacy.

Perhaps a 1g dose doesn't get all of the phoretic mites but the 2.4g or higher does?

 

[Hachi]

Do you think most people ever get to the point where they have eliminated every mite from that season's line?

No. If you watch the series the scientists say that you never kill every mite.

 

[Hachi]

Perhaps a 1g dose doesn't get all of the phoretic mites but the 2.4g or higher does?

I run Comrcl BB's which are roughly half the size again of a national BB and I only use round number grams and where I'm running double BB the amount would make your eyes water

 

[user 20297]

No. If you watch the series the scientists s

Maybe lucky mites pass on their luck to their offspring.

 

[Apinor]

From what you say, maybe varroa near you are becoming "resistant" to varroa.

It does seem an open and shut case that a strong acid is impossible to resist, if it covers the body of a mite. Since it seems to be recommended that several applications of oxalic are made, it seems obvious that some mites are avoiding being killed. That is probably because of behavioural reasons, by either accidentally or intentionally avoiding the worst of the acid. Certain parts of the hive may not be well covered by the sublimate, or bees engaged in certain tasks, (foraging being the obvious one), may miss being treated. Whatever the reasons for the survival of some "treated " mites, and regardless of how minor the factors that help towards survival may be, the behaviours or circumstances that promoted survival will slowly become consolidated within the mite population.

It's "academic" for many people who see all this as peripheral to the "fight" against the mite, but it is surprising to read that maybe oxalic acid may gradually lose some of its efficacy.

We can see a spread of dangerous virus which ends in dead hives, but that do not automatically indicate that the oxalic acid itself does a less effective job. Here are more factors, like the location of the varroa during the treatment. Are the varroa sitting under the abdomen between the sections or on top of the bee? Is it likely to belive that the varroa move around during a period of 2 months and can be more exposed to the treatment by two treatments compare to one. The dripping is no rocket science - you have no warranty to hit every single bee with oxalic acid solution by one treatment. Yes, we are in a way selecting for varroa able to avoid the treatment if all are hiding under the adomen because located there, they will be better protected compare to be riding on top of the bee. On the other hand, if 2 treatments expose the varroa for the oxalic acid and gives a better effect, it is is worth researching.

 

[Erichalfbee]

I run Comrcl BB's which are roughly half the size again of a national BB and I only use round number grams and where I'm running double BB the amount would make your eyes water

Yes my 14x12s get 3g at least. Sometimes more if a big dollop falls out of the scoop.

 

[Beekeeperscottish]

colds (mostly) are caused by viruses. antibiotics target microbial organisms - not viruses. patients demanding some form of treatment from GP's lead to poorly focused prescription of antibiotics from GP's that has lead to increased resistance to antibiotics from microbial organisms. nothing new there, been going on for decades. we have not become immune to the treatment - viruses were never impacted. other than that perfected valid statement

Hi, I was just using the antibiotics as a point to get across. We seem to be to hell bent on eliminating every single varroa when in reality they are here to stay, we need to be more like a GP and prescribe what the bees need. This obviously takes knowledge and understanding your bees. Ask 10 beekeepers a question and you will get 10 different answers