Varroa Treatments

[drex]

There is a absolutely no evidence of resistance developing to Thymol, or to OA - pretty difficult to develop a resistance to having your legs burnt off with acid

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I agree, that is why I said in theory, but I do not think mode of action has as yet been totally sorted. I think that ringing the changes is a good principle anyway.

 

[Ian123]

I wouldn't split the boxes to apply OA drizzle, just treat the seams of bees whether they are up top or lower. Use a torch to locate them if it's a problem.

Done it on hundreds of hives it’s not an issue and you are then assured of getting it on the bees not down the frames above.

 

[Ian123]

I agree, that is why I said in theory, but I do not think mode of action has as yet been totally sorted. I think that ringing the changes is a good principle anyway.

I think the physical effect on the mites is well recorded and understood.

 

[Swarm]

Done it on hundreds of hives it’s not an issue and you are then assured of getting it on the bees not down the frames above.

The aim is not to try to cover each bee, there will always be those who are underneath.

 

[Ian123]

Lol if I had suggested covering every bee we would all be there some time. The aim though is to Trickle on to the cluster so the bees will pass it around whilst cleaning and grooming. Even less would make it to the cluster if you had a double brood, just crack the boxes and be done.

 

[jenkinsbrynmair]

If you winter bees on brood and a half do you split boxes to treat also why are we told to only treat once if a second treatment would mop up a few more survivors from the first ?

No, don't split the boxes. The reason they say only trickle once a year is, as the bees will ingest the syrup as they are cleaning each other, multiple exposure can shorten their lifespan - no big deal with workers but can damage the queen.

 

[bingevader]

A lot of us use Oxalic acid sublimation and strips are now available but I guess the oxalic is man made

Any news on the strips, please? Did you find some instructions afterwards?
Ta

 

[Erichalfbee]

Any news on the strips, please? Did you find some instructions afterwards?
Ta

Four strips per brood box leave in over a whole brood cycle.

 

[Swarm]

Lol if I had suggested covering every bee we would all be there some time. The aim though is to Trickle on to the cluster so the bees will pass it around whilst cleaning and grooming. Even less would make it to the cluster if you had a double brood, just crack the boxes and be done.

The same amount makes it to the cluster, doesn't matter where it is. Treatment is per seam of bees, drizzle each one, the bees do the distributing.

 

[Ian123]

If you winter bees on brood and a half do you split boxes to treat also why are we told to only treat once if a second treatment would mop up a few more survivors from the first ?

Just to clarify if you can locate the cluster/seams of bees by cracking the crown board there is no need to split the boxes. If the bees are in the lower box then split you will do no harm, and far better that than a random squirt half a box away.

 

[Swarm]

Entirely your choice of course. I would advise against splitting the boxes when there is no need, thereby avoiding any chance of damaging the queen.

 

[Ian123]

The same amount makes it to the cluster, doesn't matter where it is. Treatment is per seam of bees, drizzle each one, the bees do the distributing.

No that’s not the case all the research says apply directly to the bees or seams of in fact some suggest liquid not getting to the bees is ignored. I bet you can’t find any that suggest otherwise..now there’s a challenge! As to squishing the queen there’s a bee space and on that basis you would never crack any brood box. The first year I trickled was early 2000s on 50 colonies the second year was about 350 I’ve never noticed any problems splitting boxes. But as you say it’s personal choice

 

[bingevader]

Four strips per brood box leave in over a whole brood cycle.

Thanks.

 

[monarda]

Many thanks Ian, Steve and Jenkinsbrynmair for your help ( interesting about bees ingesting the syrup and possible accumulative effect on queens).

 

[Beersmith]

Could I ask if anyone can post links to research into oxalic acid mode of action?

I had always considered it to be a fairly harsh chemical, acidic and harmful to humans through ingestion and skin contact. But in the apiary proven to be a very effective varroa control agent and highly selective, at concentrations that can "burn the legs off mites" the bees are largely unaffected.

This is a very desirable characteristic. The question how can we attack the virus / bacteria / parasite / cancer without harming the host is a recurring theme in health issues, bee health included. There could be important benefits in knowing more about how it works.

Cheers

 

[Millet]

There is a absolutely no evidence of resistance developing to Thymol, or to OA - pretty difficult to develop a resistance to having your legs burnt off with acid

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That certainly made me chuckle..

 

[jenkinsbrynmair]

Could I ask if anyone can post links to research into oxalic acid mode of action?

http://www.sussex.ac.uk/lasi/sussexplan/varroamites

 

[charlievictorbravo]

http://www.sussex.ac.uk/lasi/sussexplan/varroamites

JMB - that link says how effective vapourised OA is but as far as I could see, it does not state its mode of operation in killing the mites. The suspicion among most users is that the acid burns the soft foot pads and eating parts of the mites but I've never seen that confirmed by an academic research paper.

Bees have pads hidden away inside their feet, for use on very smooth surfaces, so could these be damaged by OA? I don't know - just asking.

It was so refreshing to see Dr Samuel Ramsey (University of Maryland) questioning the perceived wisdom of what Varroa feed on, leading to his discovery that they don't feed on Hemolymph but on fatbody, whatever that is. Maybe somebody should go back to basics on OA and Varroa and see if we've been barking up the wrong tree all these years or whether the "burning feet and mouth parts" theory is correct.

CVB

 

[Erichalfbee]

I remember reading something but I'll be blowed if I can remember where. At least the Sussex research points to no harm to the bees. Is there something, a link, maybe on Randy Oliver's site?

 

[Walrus]

http://scientificbeekeeping.com/oxalic-acid-powerpoint-presentation/

He says: "There are speculative hypotheses as to why acids kill varroa, but no definitive study.
Beekeeper Gerhard Bruning suspects that OA crystals are absorbed through varroa’s sticky tarsal pads."