OA done- but what next?

[Skyhook]

Oxalic done on the 28th December. However, they weren't in cluster, we've had only 2 or 3 frosts this 'winter', and I have no reason to suppose they have stopped brooding at any point, and therefore no reason to suppose the treatment will have killed a significant proportion of the mites.

I'm planning to fit in a spring treatment, but the question is the best way to go about it. I could do a short thymol treatment, but that could interfere with laying at a crucial time. My intention is to do an Apistan treatment in March- I know that resistance in my area is, at worst, partial.

Can anyone tell me what is wrong with my plan, or suggest a better?

 

[RoofTops]

"I know that resistance in my area is, at worst, partial"

In Dorset? Assume resistance.

Try a shook swarm and if there is any doubt about mites afterwards, for example you were not able to use a bait frame, use thymo/formic/OA a week after the shook swarm.

 

[Arfermo]

There is no good reason not to give them another dose of oxalic after 2 weeks since last dose. Shook swarm in spring is a possibility but is best left for when you want to renew the comb - recommended at 2 year intervals or 3 at most as that controls risk of nosema too.

 

[Finman]

Can anyone tell me what is wrong with my plan, or suggest a better?

wait first and look if you have need to Spring treatment. It is needed if OA is failed.
Watch out the amount of mites inside drone brood.

 

[susbees]

There is no good reason not to give them another dose of oxalic after 2 weeks since last dose.

Is there any research evidence for this?

One dose per colony per year and, I'd have thought, definitely one dose on the same bees (as opposed to incoming swarm then winter treatment) as any damage to them will be cumulative, makes a load of sense to me.

 

[Hivemaker.]

Is there any research evidence for this?

http://www.ncbi.nlm.nih.gov/pubmed/17624673

 

[Skyhook]

Thanks guys- I'll give a repeat of OA serious consideration.

Finman- I'm not very confidant in relying on my ability to check by drone brood monitoring. In my first year I was doing this and saw not a single mite- they were actually quite heavily infested. Not sure what I was doing wrong, but it sure didn't work for me!

 

[Finman]

Thanks guys- I'll give a repeat of OA serious consideration.

Finman- I'm not very confidant in relying on my ability to check by drone brood monitoring. In my first year I was doing this and saw not a single mite- they were actually quite heavily infested. Not sure what I was doing wrong, but it sure didn't work for me!

ok, if you think that you have extra load, it is better drop down.

2 years ago I lost 30% of my hives (10 hives) when I had missluck in treatments.

False swarm is quite good method during swarming time. I made false swarm to cut the swarming fever but I did not treated them even if I had an easy opportunity. Now I have lots of formic acid and that is may way to clean the hives during summer.

Last summer I had a plan what to do, but when yield period started, it was really high speed nectar flow. That was not a time to disturb the hives. I mean, a good plan but the result was zero.
.
I saw from brood that things were going worse and worse but I did not realize that things were allready too far.

.

 

[gavin]

Checking drone brood can be quite a good method. The main thing is to bear in mind that Varroa distribution in brood can be quite patchy. Don't rely on a single sample from one small patch of brood. Sometimes you get the impression that there was a pulse of Varroa entering brood, so if you are looking only at mature brood, repeat it again a week or two later.

 

[Gardenbees]

Checking drone brood can be quite a good method. The main thing is to bear in mind that Varroa distribution in brood can be quite patchy. Don't rely on a single sample from one small patch of brood. Sometimes you get the impression that there was a pulse of Varroa entering brood, so if you are looking only at mature brood, repeat it again a week or two later.

You definitely get pockets of infestation. It's an offputting business but opening up quite large areas of drone brood from several frames is the only way to find out the extent of the problem. For example, I find that the bottom left corner of the second frame in, on one of my hives, and the first frame in, on the other, are a good bet for lurking mites, whereas checking the drone brood on the right hand side often doesn't find any at all.

 

[RoofTops]

And remember the Fera varroa booklet says the trigger point for taking action when varroa is spotted in drone brood is just 5% - i.e. one cell in 20. So if you take a forkful of drone brood and see mites in almost every cell then you have waited far too long to take action. You should have done it when you found mites in only one cell in twenty.

Which is not very many and easy to miss if, as suggested above, the mites are not be spread uniformly.

 

[oliver90owner]

whereas checking the drone brood on the right hand side often doesn't find any at all

Maybe the cooler side?

 

[Gardenbees]

whereas checking the drone brood on the right hand side often doesn't find any at all

Maybe the cooler side?

Possibly. Also, the incoming workers seem to circulate around the hive, coming in at the bottom left and working their way around from there, and leaving more or less on the right. I suppose they might drop incoming mites shortly after entry, increasing the chance of mite load in the nearest drone cells.

I have spent a ridiculous amount of time watching them!
I haven't previously had the luxury of a long garden, so now I've got a garden apiary I'm enjoying the ease of access for studying their comings and goings...

 

[drstitson]

"whereas checking the drone brood on the right hand side often doesn't find any any"

always good to ensure that any treatments you use consist of racemic mixtures of the active compounds. Perhaps using just D or L isomers are the reason for such brood bias?

 

[kevinrrogers67]

Are you serious about optical isomer?

I am sure most people have no ideas what you are talking about.

Moreover oxalic acid, thymol and formic acid do not have optical isomers as they have no chiral centre.

 

[Skyhook]

Are you serious about optical isomer?

I am sure most people have no ideas what you are talking about.

Moreover oxalic acid, thymol and formic acid do not have optical isomers as they have no chiral centre.

I think this is the doc's warped sense of humour. I was just waiting to see if anyone really understood waht he was on about, as opposed to my spotting a reference to something I once heard mentioned on a radio programme!

 

[Finman]

.
Mite mathematics is complex

you open the whole brood area of frame and you find 10 mites.
- one drone brood produces 4 female mites
- one worker brood produce 2 female mites.

So you need 2 drone cells and worker cell and you have 10 mites. Adult mites are still alive and actually you have 13 female mites.
So 2 drone pupae may produce 10 female mites. - not evenly spread. On in one side and one in another side.

june 10 mites x 10 brood frames = 100 mites

july 200
august 400
september 800
october 1600



no wonder If you did not met mites in summer but in trickling you have 1000 mites on bottom

.

 

[Beezy]

I'm in a similar situation to Skyhook - I used oxalic a couple of days ago when there was a relatively cold day (for London) but the bees weren't clustered and I'm dubious about how effective it will be.
If I need to treat in Spring (with apiguard?) then does this mean I can't treat in late summer with apiguard again?

 

[RoofTops]

No, you can use thymol treatments many times during the year.

I wouldn't worry too much about the bees being "clustered" so long as you managed to trickle the OA down the seams with bees in them. A few loose bees flying around is not a problem - they would have all come together that evening anyway.

 

[Beezy]

Ok, thanks for the advice Rooftops