Varroa in February

[alanf]

In one hive I seem to have a varroa problem. A drop test over the last week and a bit produced over 10 a day. The hive only 2 metres away dropped no varroa in the same period. The NBU calculator estimates 10 a day in February as mites in the thousands. I'm not entirely sure the variables at this time of year make that an accurate estimate, but it's enough for concern.

I knew there was a problem last October and tried Bayvarol, yes all sorts of caveats, but it dropped a couple of thousand. Clean I thought, but drops in December suggested a few hundred so dribbled oxalic into what looked like a broodless hive in late December. They dropped about 500 over the next couple of weeks.

Now the drop continues, they could be clearing some previously dead varroa, or some other explanation for a freak drop so I'll try another count. If that confirms the high numbers I'll treat. But the question is with what? I'm thinking the best option might be vaporising oxalic because if the mites are that stubborn, it could need repeats before spring kicks in. Any other ideas?

 

[mbc]

Could be clearing out previously dead varroa, but either way with that history I would consider requeening them with stock that behaves less like a varroa magnet.

 

[Hivemaker.]

Alan, if your future observations indicate a need to treat, then treatment with oxalic sublimation would be a good option, another option would be to obtain some Apivar strips to treat them.

 

[The Drone Ranger]

Hi alanf
I would agree that an oxalic treatment with an evaporator is probably the best option
It may be there was some brood in the hive when the trickling took place
Thats unfortunate from a varroa point of view but those bees will not have been exposed to oxalic so they are not being double dosed
The evaporated oxalic operates over a period of (my estimates 5 weeks) but the initial effect is very dramatic
The strips are another option but the bees will only get exposure as they contact the strips thats why they need a bit longer before the mites start to be killed in large numbers
Best of luck with them

 

[Cazza]

You could also give Hiveclean a go. It's what I use at this time of year if required.
Cazza

 

[domino]

Alan, if your future observations indicate a need to treat, then treatment with oxalic sublimation would be a good option, another option would be to obtain some Apivar strips to treat them.

Is there a guide to this, I've zero experience with this method.

 

[alanf]

Is there a guide to this, I've zero experience with this method.

Which method?

Apivar contains Amitraz, it's a strip you hang similar to Bayvarol or Apistan. But is only from a Vet. Several who do stock imported Apivar are mentioned in previous threads, they all have a form of wording such as:

Please note that this amitraz product is not licensed for general resale in the UK and is only available on prescription from a vet with a Special Import Certificate (SIC). Please remember to leave a contact telephone number so we can discuss your needs further before processing the order.

For oxalic vapourising, the most often mentioned equipment is the Swiss made Varrox, Dave Cushman reproduced the leaflet as it was supplied a few years back: http://www.dave-cushman.net/bee/oxalicthorne.html. There's a Ukrainian guy selling something like a copy on ebay at a fraction of the price.

Thanks for suggestions, I'm reluctant to risk losing them or replace the queen because they were very strong and my best yielding hive last year. Although I saw no brood before oxalic trickling it wasn't a full examination, just a check on frames where I'd expect brood so I might have missed some further along. Most of the research I can find suggests repeat trickling is more likely to cause problems that repeat vaporisation. I was a bit complacent over summer perhaps in that if they were doing so well, there couldn't be that much wrong; that came back to bite than. I haven't tried either method before, I'm a bit wary of adding another chemical (Amitraz) so at the moment getting a Varrox seems the best bet.

 

[itma]

I'm going to suggest that buying a Varrox (and the personal protection kit) isn't really justified for 2 hives.

I'd suggest that with (hopefully) most but not all mites being phoretic, you might as well hit them with ... icing sugar! It will (like Oxalic but not quite so effectively) knock down phoretic mites, while (like Oxalic) leaving those in brood cells untouched.
After they have emerged from winter, I'd treat them with Formic (MAQS), which should deal with those in brood cells as well - while not tainting the crop.
Assuming that from here on, there are going to be brood cells, Formic (or a long, honey affecting, treatment) is going to be called for.
However, it'd be better to wait and do Formic in April/May when the colony is stronger and able to re-queen should that be necessary (hopefully not).
So, what's needed in the interim is a stop-gap to limit the problem in the meantime. And icing sugar should do that - at essentially zero risk.

 

[user 6228]

Or do nothing at all and see what happens... had a hive that was producing a LOT of varroa fall, we left them alone, following year that colony became 5 and the following year 11... (Though our bee's habitats are not common issue)

Your mileage may vary...

The interaction between bees, varroa and treatment/non treatment is rather puzzling.

Derek

 

[MuswellMetro]

Alan, if your future observations indicate a need to treat, then treatment with oxalic sublimation would be a good option, another option would be to obtain some Apivar strips to treat them.

I had the same problem tw years ago and obtained Apivar(amitraz) from a Vet in dumfries

http://www.bridgevets.com/bees but the BeeVet advertises it in bee-craft as well

about £28 for five hives, now that apairy is almost varroa free with just apivar

 

[Jimmys Mum]

I had the same problem tw years ago and obtained Apivar(amitraz) from a Vet in dumfries

http://www.bridgevets.com/bees but the BeeVet advertises it in bee-craft as well

about £28 for five hives, now that apairy is almost varroa free with just apivar

Same here last year. Worked a treat!

 

[Heather]

Is it worth removing/dumping all brood in a few weeks then icing sugar them?

 

[Black Comb]

I'm in a similar position in one apiary.

Which month did you treat with apivar?

 

[drstitson]

Hi - you have a problem assessing varroa load. when exactly did you actually treat ("late" dec could be anything from 21st to 31st!).

Oxalic is oft quoted as working over 4-5 weeks (with max drop week 1).

you say you treated late dec. first week of feb is only 5.5 weeks since new year (remember Sherlock is still fresh in our minds).

So that 10 a day may not represent a true natural drop but rather the tail end of a very successful treatment.

actually you state "A drop test over the last week and a bit produced over 10 a day." your post was dated 7/2/14. So that could indicate a drop that occurred during the period from around 4-5.5 weeks post OA assuming new year's eve hit. well within the OA effect period.
not many people routinely monitor a month out from winter OA - those interested may check drop over first week but otherwise the routine is very much "hit and run" as in OA during xmas holiday (to get out the house when great aunt visiting). hive then not touched until a mid to late feb quick peek - in order to avoid being caught out later on in march.