REaction to thymol- a possible opportunity?

[Skyhook]

I put thymol treatment on my 5 hives a fortnight ago before going on holiday. I inspected today while opening up to replace the oasis.

2 of the hives had heavy drops (around 800 each over 13 days), and 1 had a drop of about 150; but all 3 of these had no eggs, brood or larvae. (The other 2 both had sealed brood and eggs, and 1 had larvae.

My take on this is that their reactions to thymol varied- the one with ELB had little reaction, the one with eggs and brood had a short break in laying but has come back on, and the other 3 have gone off lay and thrown out all the brood. The 2 with the highest drops I thought had pretty high infestation rates.

Is there any reason why I should not now treat these 3 with OA trickling? A) they are broodless which, if we have a mild winter, might not happen again, and B) I could then remove the OA and let them start raising bees again.

Can anyone see a problem with this? Or does anyone think that a third way would be better, eg formic acid spray? I'm used to OA trickling and confident with it- I'm not sure how easy it it to get the right dose with spraying.

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[jenkinsbrynmair]

You're already doing Thymol - don't you think you should then give your bees a chance to get themselves sorted again? otherwise you might end up with HM going totally off lay for a long while. In any case - you're better off with a tight winter cluster when you OA them

 

[Hivemaker.]

Can anyone see a problem with this?
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No problem, do it last thing in the evening and remove the thymol treatment so the queen will start laying up again, there will be plenty of young winter bees then which will not of been affected by the oxalic.

 

[Finman]

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You continue now thymol treatment one week more and that's it.

I have never heard about formic acid spray. It is ment to gasifye but it is alternative to thymol.

Thymol efficacy is not enough in brood hive and that is why oxalic trickling is usefull.

 

[Erichalfbee]

thymol treatment on my 5 hives a fortnight ago

2 of the hives had heavy drops
3 of these had no eggs, brood or larvae.


Is there any reason why I should not now treat these 3 with OA trickling?
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One of my hives is in a similar state and I was wondering exactly the same thing.

 

[Poly Hive]

I am amazed.

Formic and Lactic acid treatments were amongst the first to be trialled in Europe.

The German trials said that in broodless conditions the Formic spray was highly efficacious.

"(Liu and Nasr, 1992) and Wilson et all, 1993, showed that three applications of 65% Formic acid at 40ml per colony at 4 day intervals killed 89-90%"

Clark (1995) and Szabo (1995) showed that 5-6 applications of 65% formic acid at 3-4 day intervals reduced the mites by 90%

Application was by measured dose to kitchen towels which were then placed on the top bars.

PH

 

[Skyhook]

Interesting update. To recap, in September I treated my 5 hives with thymol. 3 of them had a strong reaction and threw out the brood. I removed the remaining thymol from these 3 and treated with OA. The other 2 I finished the thymol treatment as usual.

I have just had the mite boards in to check the count prior to my normal winter OA. One hive which kept the thymol is not on OMF. The other had a drop of 86 over 2 weeks. The three which had OA in September had drops of 8, 2, and 2 respectively.

This has given me a renewed faith in oxalic, and made me think of other times it could be used. The obvious one is on a newly hived swarm, but also after AS.

Any other ideas?

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[Black Comb]

Shook swarm

 

[Tom Bick]

Just out of interest how long into thymol treatments when you stopped and did you know the drop following the OA of the three hives back in September?

 

[oliver90owner]

This has given me a renewed faith in oxalic,

3 of them had a strong reaction and threw out the brood.

Renewed faith? Not necessarily so, I would suggest. The thymol treatment was likely very effective against the mites - too much in fact, because of the adverse colony reaction to the treatment reported.

A bit more thymol and your colonies could have absconded?

The oxalic may have mopped up a few varroa, if that, and was unnecesssary at that time, IMO. The thymol was clearly a bit too strong at some point on some of your colonies?

So need further details to be sure your faith is really down to the oxalic. Or perhaps we should simply remove all brood in the autumn and treat with oxalic instead of thymol?

 

[Erichalfbee]

I had one hive broodless after two weeks thymol.See post 5.I checked all the frames as the weather was good. I thought that as they were broodless I might as well not put in the next strip and stopped treatment entirely.I was keen to get those winter bees being made. That hive, a 14 x 12, dropped 20 mites after oxalic.

 

[Finman]

I am amazed.

Formic and Lactic acid treatments were amongst the first to be trialled in Europe.

The German trials said that in broodless conditions the Formic spray was highly efficacious.

"(Liu and Nasr, 1992) and Wilson et all, 1993, showed that three applications of 65% Formic acid at 40ml per colony at 4 day intervals killed 89-90%"

Clark (1995) and Szabo (1995) showed that 5-6 applications of 65% formic acid at 3-4 day intervals reduced the mites by 90%

Application was by measured dose to kitchen towels which were then placed on the top bars.

PH

POlyhive mixes here something. I have never met Formic spray. It is allways 65% acid which slowly evaporates above frames. Because it does not affect miten under brood cappings, it must be renevew after a certain days.

Kitchen towels yes and it into a closed plastic bag. Then a wound onto a bag and acid evaporates.

65% acid kills skin from hands if touches the skin. I gives no pain signal.

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[oliver90owner]

That hive, a 14 x 12, dropped 20 mites after oxalic.

Yes, perhaps the hives need at least as much thymol vapour as to put the queen off-lay to be effective? I assess mine by the response of bearding on the front of the hive.

Jumping to the wrong conclusions is so easy if you only look to 'substantiate' your initial thoughts, as it very much appears to be, in this thread. Things often need a slightly deeper analysis than a superficial 'no mites must be down to the oxalic'.

 

[alanf]

Interesting update. To recap, in September I treated my 5 hives with thymol. 3 of them had a strong reaction and threw out the brood. I removed the remaining thymol from these 3 and treated with OA. The other 2 I finished the thymol treatment as usual.

I have just had the mite boards in to check the count prior to my normal winter OA. One hive which kept the thymol is not on OMF. The other had a drop of 86 over 2 weeks. The three which had OA in September had drops of 8, 2, and 2 respectively.

This has given me a renewed faith in oxalic, and made me think of other times it could be used. The obvious one is on a newly hived swarm, but also after AS..

You have three hives which were broodless under a thymol treatment in September. Your observation is that the broodless state was because of the thymol, but many colonies become broodless without thymol at that time of year, as Hivemaker often points out. Whichever way, the broodless state often has a varroa control effect, after shook swarms for instance. And we know thymol works on the mites that are not trapped in brood cells, so any mites in the broodless colonies will already have had a thymol dose. There is nothing to say that the addition of oxalic had any extra effect over and above the thymol/broodless treatment. Maybe it did, but to know the oxalic made a difference you need to compare colonies that were treated with oxalic with those in the same broodless/thymol state that were not treated.

 

[Skyhook]

Just out of interest how long into thymol treatments when you stopped and did you know the drop following the OA of the three hives back in September?

The treatments were on for a fortnight- I put them on before going on holiday. All had heavy drops in the high hundreds.

I'm afraid I didn't check the drop again afterwards- I don't like having the boards in too long, and as I wasn't planning to treat again at that point, there didn't seem any point.

 

[Skyhook]

This has given me a renewed faith in oxalic,

3 of them had a strong reaction and threw out the brood.

Renewed faith? Not necessarily so, I would suggest. The thymol treatment was likely very effective against the mites - too much in fact, because of the adverse colony reaction to the treatment reported.

A bit more thymol and your colonies could have absconded?

The oxalic may have mopped up a few varroa, if that, and was unnecesssary at that time, IMO. The thymol was clearly a bit too strong at some point on some of your colonies?

So need further details to be sure your faith is really down to the oxalic. Or perhaps we should simply remove all brood in the autumn and treat with oxalic instead of thymol?

Fair point. Interesting though, that the hives that didn't throw out the brood had had exactly the same treatment. They then received their 2nd dose, and yet the one I'm able to check on now has a very high mite count.

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[Skyhook]

You have three hives which were broodless under a thymol treatment in September. Your observation is that the broodless state was because of the thymol, but many colonies become broodless without thymol at that time of year, as Hivemaker often points out. Whichever way, the broodless state often has a varroa control effect, after shook swarms for instance. And we know thymol works on the mites that are not trapped in brood cells, so any mites in the broodless colonies will already have had a thymol dose. There is nothing to say that the addition of oxalic had any extra effect over and above the thymol/broodless treatment. Maybe it did, but to know the oxalic made a difference you need to compare colonies that were treated with oxalic with those in the same broodless/thymol state that were not treated.

That may be part of the answer, but not all. The reason I said they threw out all their brood was the large amount of bits of pupa.

Looking at my notes, I see that one hive I had noted 4 weeks before as ELB 'wall to wall'

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[Hivemaker.]

They then received their 2nd dose, and yet the one I'm able to check on now has a very high mite count.

Did you do a third thymol treatment?

 

[Skyhook]

Did you do a third thymol treatment?

No. I feel that thymol supresses laying even if it doesn't stop it. I was rather late treating, as they only stored honey about mid-august up to early sept, and I wanted to take a bit of honey off if possible. I was therefore late getting the thymol on, and anxious to get it off again while they still had time to raise a few more bees.

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