Deformed wing virus

[scaie]

I saw two new hatch bees being taken out of the hive this weekend with deformed bee virus. I have treated the hive with MAQs strips, is there anything else I should do? I haven't inspected yet.

[Jon]

That sounds like a reasonable course of action if you have a lot of mites in the hive.
Have a look in the first decent weather day.

[fatshark]

When did you treat with MAQS? If just recently remember that the newly emerging bees will have become infected during early pupation when Varroa enters the cell. Therefore you won't see the benefit until the brood cycle laid during or after MAQS treatment start to emerge.

Did you treat with oxalic acid? If the winter was warm(ish) where you are it's possible the colony had brood all winter and kept the Varroa going. Uncap some drone brood at the first opportunity … that's where the little blighters will be lurking.

[gavin]

I don't have experience of MAQS but presume it should be effective. An alternative could have been drone brood trapping which can be effective at this time of year. If your colony has very little drone brood but is building strongly, put a shallow frame at one side of the brood nest then a second a week later at the other side. That puts almost all of the drone brood below the bottom bar of those frames. Cut that off when sealed and Varroa is greatly reduced.

[scaie]

When did you treat with MAQS? If just recently remember that the newly emerging bees will have become infected during early pupation when Varroa enters the cell. Therefore you won't see the benefit until the brood cycle laid during or after MAQS treatment start to emerge.

Did you treat with oxalic acid? If the winter was warm(ish) where you are it's possible the colony had brood all winter and kept the Varroa going. Uncap some drone brood at the first opportunity … that's where the little blighters will be lurking.

I put MAQs on after I saw the deformed wind bees, so this weekend. No I didn't treat with oxalic acid but I do think this colony has had brood either all winter or very early on. Is it too early to do an inspection/ drone uncaping?

[scaie]

Drone brood trapping is a good idea. I did a count of verroa 2 weeks ago and during a 7 day period I counted a drop of 16 which I didn't think was too bad??

[gavin]

Drone brood trapping is a good idea. I did a count of verroa 2 weeks ago and during a 7 day period I counted a drop of 16 which I didn't think was too bad??

Be guided by conditions for inspecting. Generally when it hits 15C is a good time, but you can risk a quick peek a little cooler than that if you're quick.

For me, 16 mites in a week if the hive was untreated isn't great but there would be no need to rush into anything. If you've used MAQS that should knock them down substantially, and also give you higher counts for a while. If you hadn't treated, the drone brood trapping lets you check the extent of the problem while reducing it at the same time.

In early spring I sometimes see deformed wing bees and may struggle to see any a few weeks later. Maybe the small amount of new brood hatching early in the season makes them obvious, then they are hard to spot later as the ramping up of brood production means they're swamped by healthy ones. Maybe most of the Varroa causing that early spring damage were on their last legs and the problem fades for a while. Anyway, your problem should be fixed now.

[scaie]

Thanks for the advice, I was worried because David Ashton's book was mentioning burning frames, etc. I'm glad you don't think its too serious. I did treat with MAQs strips in September but the cluster was big and I think it had had brood early because it was so mild here.

[gavin]

Thanks for the advice, I was worried because David Ashton's book was mentioning burning frames, etc. I'm glad you don't think its too serious. I did treat with MAQs strips in September but the cluster was big and I think it had had brood early because it was so mild here.

Ah. I'd assumed that you were treating with MAQS right now, and that the 16 mites were knocked down rather than natural drop. OK then, keep monitoring, keep an eye on it, and if I was you I would try something like drone brood removal (and have a look in the sacrificed drone brood as an extra check on the Varroa level). That number is higher than you'd really want it to be at this time of year. No need to burnframes though.

[scaie]

Yes I am treating with MAQS now but I also did in September. The 16 was a natural drop before I started this treatment

[HJBee]

I don't have any obvious sign of DWV, but I do have a hive showing higher levels of Varroa drop than I like, and compared to the 4 hives also in the apiary. I could try a formic acid treatment I believe, and after reading this months Scottish Beekeeper and discovering MAQS is formic based, if this could be a potential. However, my concerns are
A) mixing treatments. I've used Apivar for the past / years as my autumn treatment.
B) effect on the queen who is laying well
C) effect on honey products subsequently ( I believe you can leave supers on?)
Any advice? Is my count of a level to be concerned enough to treat? This hive has little capped drone brood as yet.

[gavin]

Hi HJ

You get brownie points for alternating treatments - it is regarded as a good thing as you're less likely to get resistance building up that way. Some say the formic acid methods risk harming the queen but more than likely at this cooler time of year it would be safer. Formic acid is a natural component of honey, so if the treatment leaves traces in the honey you wouldn't notice. If your colony has little capped drone yet then it is probably also not at honey gathering strength yet. That also means that it can be a good time to try drone trapping as discussed above.

How many Varroa were you getting?

G

[HJBee]

About a drop of 20 in 2 weeks, various sizes. The colony is not as strong as the other, both queens hatched at the same time last year, apart from that there is a lack of stores being brought in so I've actually fed them this weekend.

[gavin]

Well, the online calculator (https://secure.fera.defra.gov.uk/beebase/public/BeeDiseases/varroaCalculator.cfm) suggests that you'll need to treat wthin 3 months if you do nothing now, and that sounds about right to me. This early in the season I don't like to see much of a mite fall.

[HJBee]

That would mean a treatment late July. I will do another count this weekend as a measured control and really look at the bees to see if there is any obvious sign of deformity / mites while the colony us still small to see the frame and larvae and then I need to make a decision. Thanks for the link and advice. H

[snimmo243]

Well, the online calculator (https://secure.fera.defra.gov.uk/beebase/public/BeeDiseases/varroaCalculator.cfm) suggests that you'll need to treat wthin 3 months if you do nothing now, and that sounds about right to me. This early in the season I don't like to see much of a mite fall.

I used the beebase calculator religiously up until this winter. At my last autumn count the calculator said treat in 11 months, fast forward to December and my natural count was well above the danger threshold and I was getting a few thousand after oxalic so now I'm just using the paper calculations and using 1000 per colony as the threshold

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[HJBee]

I did treat with Oxalic in early Jan already - last September for the Apivar. Don't know if I am being too paranoid. Will give them a further study and a clean 7 day count at the weekend.

[HJBee]

7 day count has confirmed a high drop level - at least 20-25. Treatment time, going to have a look at a method recommended by one if the locals and see if I feel ok with attempting that or will get the MAQS. Other colony, no signs.

[HJBee]

Just a wee update, treated 2 hives with MAQS - 1 because I was worried re the drop count, the other as the treatment came in packs for 2 hives , and I have 2. Treatment was real easy to apply, the count on the hive I had main concern for after 4 days (1/2 way) was in excess if 200, I was amazed and glad I had made the decision to treat. The other hive not so much at all (more concerned re chalk brood increase from - could have been the very wet weather or the treatment). Took the treatment off this Tue, count had not increased significantly. Both hives were hoaching with bees, both still had eggs. Quick check last night slight drop still on the hive that had been affected, none apart from still small signs of chalk brood in the other, brood wall to wall, stores, pollen, no signs of swarming, all's good in the world. They can get on with filling the supers with wax. & nectar now.

[Jon]

HJ
200 mites is not really excessive for this time of year but removing them will do no harm of course.
You probably have 30,000+ brood cells in the colony at the moment so most pupae will not have a mite in the cell.
Doubling mite numbers every month without treatment you could have around 1000 mites by mid August which is the usual time for treatment.
That is just about as high a level as you would want to reach but you would probably get away with in in a strong colony.

[HJBee]

Hi Jon, we have never seen a mite count like this in any of the hives in may, so why I treated now (used beebase calculator & decided was not worth the risk to wait). Will treat with Apivar in early Sept as usual (as I did last year) this one hive is just very different to the rest. H

[mbc]

treat with Apivar in early Sept as usual (as I did last year) this one hive is just very different to the rest. H

Sounds like you might have amitras resistant mites, unless this one colony was subject to a lot of varroa re invasion since the last treatment.