Oxalic Acid.

[Bobs-bees]

Carried out Oxalic acid treatment on 3rd January 2013. This after NOT doing any other treatment last year.
Hive contains 7 seams of Bees. I have been feeding Fondant since late November.

4th Jan Day 1. 39 Varroa.
5th Jan Day 2. 140 ..
6th Jan Day 3. 66 ..
7th Jan Day 4. 51 ..
8th Jan Day 5. 38 ..

I suppose you can double these findings as there will be trapped varroa on the mesh floor, also on the bottom bar ledge of the frames.
Quite pleased about these results so far BUT there is still a high risk of losses as the weather is about to change back to winter mode.
Bob. In not so sunny Rainham. Kent.

[Mellifera Crofter]

I yesterday counted the mite fall from ten hives over eleven days. It worked out at .036 mites per hive per day - a mite leg per day? (Four mites altogether in total.)

As I've mentioned earlier, I've not treated with OA so I suppose you'll tell me I should not feel too happy just yet - that they're there and I just don't know about it.

I'm not for or against OA - I'm just a bit reluctant about it. Acid over the bees in the middle of winter ...

Kitta

[Jon]

Hi Kitta
There is plenty of research to show it does them no harm. It's an acid but only at 3.2% strength. The Acetic acid at 80% used for fumigating frames and bee equipment is dangerous stuff but the Oxalic at that strength is a fairly benign product. It's best warmed to 30c before being applied.

Re. the natural mite drop, the official advice is to treat if necessary when the mite drop is above a certain level.
Personally I find this completely unreliable. Over the summer I sometimes don't see a mite for months then when treatment starts you can have several hundred drop over a day or two.
If I treated 10 hives I would find a couple with next to no mites dropping and a couple with quite a high mite drop. You just can't tell which is which until you treat.
Mites plus their vectored viruses is still the main problem in beekeeping.

[Mellifera Crofter]

Thanks Jon. I thought you might say something like that, and I'm sure you're right. Maybe next winter ... I did treat them with Apivar in September and will do so again in spring.
Kitta

[snimmo243]

I have some Oxcalic trickle left over, enough for 1 hive if anyone in West Lothian area needs it

Steven

[EmsE]

I applied the OA to my colonies last weekend and was pleasantly surprised at the strength of them. The pre treatment varroa drop was checked for one of the hives (hive 7) which was 3 mites over 7 days. Post treatment results were
Hive 1) 86 mites / 6 days
Hive 2) 49 mites / 6 days
Hive 6) 5 mites / 6 days
Hive 7) 158 mites / 6 days (different site to the rest)

It's good to see that the OA has had an impact.

[Jon]

Those are fairly typical results. I see a lot of variation in mine as well. I only monitored 4 of mine out of about 30 and one of them dropped about 250 mites over 10 days. Your hive 3 could have gone without a treatment but there is no way of knowing that beforehand.
They will all benefit from the reduced mite load.
A colony starting the year with 150-200 mites could well be in trouble by June with a mite load over 1000 by that stage.

[Mellifera Crofter]

... It's good to see that the OA has had an impact.

Those are fairly typical results. ...

EmsE and Jon, how, or with what, did you treat your hives in the autumn, and what were the results then?
Kitta

[Jon]

Apiguard on almost all of them except for a few nucs which were treated with Apilifevar which was on offer from Thorne.
I started treating from the middle of August when I got the supers off.
Again, I only monitored a few and the mite drops were not exceptional, maybe a couple of hundred.
I suspect the thymol based treatments were not as effective as usual as it was very cool weather here for most of the treatment time and thymol treatments work best when the temperature is over 15c.

[nemphlar]

I used a thymol autumn treatment on 7 out 9 the other 2 were given FA and from the drop seemed quite effective at the time. The queens in the 2 FA hives continued to lay late into the year and are bigger where the thymol hives stopped. after OA treatment in mid December, with 1 exception the bug drop in the thymol treated hives is low in double figures after 4 weks, while the 2 Fa's and 1 larger thymol hive were in hundreds less than 200 admittedly. Does seem unavoidable that a prolific queen will give perfect conditions for varroa