Varroa resistant to Thymol

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So if they survive because of some behavioural trait that hides them from the thymol and that trait is passed onto their issue then isn't that regarded as a form of resistance? If they manage to avoid contact with the thymol then the modus operandi of the attacking agent is academic.

Paul
 
Suppose it depends on weather avoidance can be classed as resistant,if they are confined as when a resistance test is carried out, and they all die,then normally they are classed as none resistant,but you could i suppose class mites that are living on bee's in a hole in a tree as resistant,as they are avoiding treatment.I would say that some of the poor effects with thymol is operator error/bad application,beesrob would be a good example placing apilife var on the end bars of a nuc,which is in a huge 14x12 omlet beehaus,may just as well put the treatment under a bucket 100 yards away.
 
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It is not rare that varroa handling is not as good as it should be. You find it half year later and you cannot know, what went wrong. It just happened.

So it is commond that more or less mites will be alive. But it does not mean automatically that soon you have that and that resistant mite stock. But if it happens, it happens and then we try something else.
 
Hivemaker,

in a huge 14x12 omlet beehaus

Might have nearly as much effect - you are right. The OMF in a beehaus is ideal for taking up thymol from some distance away. Main trouble might be keeping any fumes/vapours/gases confined in the hive for more than about 5 minutes. But there is a flappy board underneath....

Regards, RAB
 
report from Hertfordshire St albans branch news letter


"I am still getting reports of colonies that have disastrously high Natural Mite Mortality drops and are still throwing out bees with tatty wings. These high mite drops are a sure sign that the colony will almost certainly die over winter.

It seems that Thymol has lost some of it’s effectiveness, or is it just the way it is being used? And I wonder how much longer it can be relied upon as a sole Varroa treatment. With 15 or so generations over a single year the natural selection, (survival of the fittest), of Varroa populations to change is very rapid.

With the very warm weather we have been having, (my bees still collecting pollen in late November), the bees are almost certainly still raising brood and therefore so are Varroa mites.

I put a single strip of Apistan in a colony of mine on 18th of October, the next day there were 500 or so mites on the tray. The number of mites then went down to 80 per day over the next 5 days and by the 31st. October there was only 15 mites per day. On 6th November the number of mites reduced to 0 per day. They are now dropping just 1 or 2 per week and if that is just natural mite mortality there can’t be many mites left in the colony. I counted 1800 mites dropped over a 19 day period."


this mirrors what was said by our science officer and apary manager at our AGM (London), perhaps its just the weather but i think it could be behaviuor of the varroa mite
 
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Whats a science officer?
Is it a branch member with a ph.D in Apiculture?
 
For a start anyone who relies on any single treatment for varroa is flawed in their strategy.

They are right that these colonies are in severe peril. The simple mite-drop monitoring should/would have shown this much, much earlier. Simply not checking for mite fall was the first error. Not checking after treatment was another. Atre these reports from beekeepers or just keepers of bees?

Thymol has not lost it's effectiveness. Well, not with my colonies, anyhow. It will kill bees if not careful.

The colonies were heavily loaded with varroa infestation at around 2000 mites. If I remember correctly a thousand is regarded as a treatment threshold (in the UK). The apistan treatment may have been be adversely affected by resistant varroa, so there may have been many more that were not killed.

Looks like they need an oxalic acid treatment PDQ and hope they survive. Spring build-up may be delayed as well, if they survive.

Sometimes I wonder why people can be so naive regarding varroa treatment. There is so much written on the net, so much in Defra publications, so much anywhere and here we have someone saying 'sole treatment for varroa'. Bl**dy amazing. I would think that these people using thymol are simply not doing the job properly, just applying and assuming. We don't actually know if it was thymol or apiguard either.

Regards, RAB
 
That letter was earlier. I have been using thymol 8 years,no resistance yet,
 
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Resistant varroa mites in the UK

Beekeeping News & Events | Beedata Home


The eventual emergence of pyrethroid-resistant varroa mites in the UK was
inevitable; which is why we at Vita have been promoting product rotation and
IPM systems in beekeeping for many years. How the resistance was caused is
really academic but that does not mean legitimate product labels should not
be adhered to. These documents after all are derived through years of trials
and final approval by the country authorities.

Here in the UK two closely-related varroacide treatments are approved [by
the Veterinary Medicines Directorate], Apistan and Bayvarol. Where there is
resistance to pyrethroids, the efficacy of both products will be
compromised.

Besides Apistan, Vita is researching into several new treatments for
honeybee health. Our thymol gel product Apiguard is undergoing pan-European
registration at present (as well as in other continents). It is unusual in
already being available to beekeepers in the UK under the label of a
"non-medicinal curative substance" but should be a veterinary medicine here
as in most of the EU by early 2002).

We developed this product with beekeepers, bee institutes and Universities
in mainland Europe - trials notably in Italy, France and Germany in
pyrethroid-resistant mite areas. Apiguard works very well against varroa
mite as well as other pests. Average efficacy is 95%, higher in warmer
climes, sometimes lower in colder areas. Even with our specially developed
slow-release gel system there is some temperature dependence but we believe
that this can be overcome in cooler areas by extending the treatment period
slightly and by spreading the gel out. Noone is claiming that by using
Apiguard 99% of mites are going to be controlled every time - sometimes
maybe but probably not every time. Thymol works in a completely different
way to pyrethroids, so unlike with some other substances, such as
organophosphates there is little risk of cross-resistance occuring. Apiguard
treatment will control pyrethroid-resistant mites.

In the UK summer seems to pass us by so quickly. When the sun appears in a
blue sky for more than three hours at a time, the use of hose pipes is
immediately banned and women and young children start fainting in the street
with heat exhaustion.
Despite the British weather, Apiguard has been used pretty successfully by
many beekeepers even here. It may not be the perfect solution but with some
modification to treatment duration and method it should serve as a useful
tool, as an alternative to or in rotation with other treatment methods. And
it is legal!

We are working on other natural control agents for varroa (including a
pheromone blend; NB this will unfortunately not be ready for at least
another 18 months) as well as natural agents for the control of foulbroods
and chalkbrood. Any profit made goes back into R&D for new products for
honeybee health.

Yes, there are the first signs of pyrethroid-resistant varroa in the UK but
if beekeepers start doing something about it now - ie by using a multiple
attack and/or product rotation system the resistant mites can be limited and
it will prolong the lifespan of all existing and future treatment regimes.
This is no time for thunder clouds of despair and doom, there is much to be
positive about, providing beekeepers will accept Integrated Pest Management
principles and use additional or rather alternative tools.


Dr Max Watkins
Vita (Europe) Limited
21/23 Wote Street
Basingstoke, Hants RG21 7NE UK
 
Looking at the original post on this thread it refers to someone using "thymol crystals". My experience of this is limited to trials we did in our branch apiary a few years ago - we have had pyrethroid-resistant mites longer than anyone here in the South West. The results of the rather limited trials were "don't bother".

I think the crystals are too dependent on temperature and probably humidity to be effective.

As others have said, reports like this I view as just scare stories and unless there is clear evidence that the thymol was used correctly (and I would only recommend Apiguard, although there are home-made alternatives) these report should be ignored.

Resistence may yet happen but the last I heard on the subject was because of the way thymol works resistance is considered unlikely.
 
Like many on the thread I'll remain unconvinced that there is real resistance operating here, but bear in mind that this is a treatment that kills mites and not bees. The bees must have tolerance, so it is theoretically possible that the mites can develop it too.

There are beekeepers - one I know with over a hundred colonies - using thymol crystals successfully as their only Varroa treatment, and have been doing so for many years. As with any thymol treatment there are things you need to remember to get it right such as the necessity of putting the thymol in a warm spot over active brood raising, and the need to replace the thymol so that it is continuously present over several weeks.

G.
 
that's a gorgeous coloured hellebore Erica, I've got two clumps and both look like chicken skin from the freezer!

Anyway, reason for posting is that I looked at the floor insets from 2 hives OA trickled on Saturday - maybe as much as 500+ mite drop although both had only nominal mite drop after full Apiguard treatment in Sep/Oct.

So the little sods are obviously Thymol resistant !!

Bayvarol next Winter./...
 
So the little sods are obviously Thymol resistant !!
QUOTE]
Unlikely - no evidence of them developing a resistance anywhere - it's probably just the natural build up since Apiguard - which is why we do oxalic in the winter.
When did you do the Apiguard, and did you finish the whole course?
 
don't think so Jenkins

I seem to recall MuswellM reporting something similar 4 /5 years ago in North London
 
HM

ok, I'll change it to "possibly" resistant but was it really necessary to make such a deprecating comment?

............. I suggest you do a google search " thymol resistant varroa "
 
............. I suggest you do a google search " thymol resistant varroa "

I suggest you do one, there is a thread on here about it from five years or so ago..
 
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HM

It was you who added "confirmed" my post was merely an observation

yes, I've already seen MM's, whats your point?
 
yes, I've already seen MM's, whats your point?

Have you called and informed the NBU to have testing done, your observation is a very serious issue. They tend to send out letters warning of resistance, like they did with pyrethroid resistance, along with test kits.

So the little sods are obviously Thymol resistant !!
 
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