Varroa drop in February

[mbc]

I have noticed some varroa drop on the inspection boards of two of my three hives, approx 12 on each board. Should l treat before brooding starts in earnest?
I treated with apilife var in autumn and trickled OS mid December. l do not have the equipment for OS vaping.

The great Finman noted an interesting observation that a false reading can be had early in spring as lots of previously dead varroa haphazardly lodged in empty cells can be cleaned out to fall on your monitoring board.
If you do think you have a worrying varroa load maybe a good intervention at this time of year would be to "improve your hive hygiene" with some oxalic/glycerine strips from abelo.
https://www.abelo.co.uk/shop/varroa-control/oxalic-acid-strips/

 

[Boston Bees]

If you do think you have a worrying varroa load maybe a good intervention at this time of year would be to "improve your hive hygiene" with some oxalic/glycerine strips from abelo.

Have you used these?

 

[Newbeeneil]

Ooooooooh, I love the wording on the advert. Says nothing about Varroa

I think Dani has used them for this specific reason.

 

[Boston Bees]

Ooooooooh, I love the wording on the advert. Says nothing about Varroa

I think Dani has used them for this specific reason.

Let's suppose someone wanted to use them illegally for varroa control. How would they even do that with these strips? What is the delivery mechanism?

 

[jenkinsbrynmair]

Let's suppose someone wanted to use them illegally for varroa control. How would they even do that with these strips? What is the delivery mechanism?

Royal Mail Second Class usually

 

[Boston Bees]

Royal Mail Second Class usually

It's OK, I found some useful answers on another thread.

 

[Newbeeneil]

Oooooops wrong place

 

[mbc]

Have you used these?

Nope, I have a friend who's used a 50/50 oxalic/glycerine mix on cardboard strips hung on the side of the nest to good effect, I've no reason to doubt these commercially available strips wouldn't do an equally efficient job.

 

[elainemary]

I usually change the board every 7 days and monitor for 3 weeks. Much longer than that and there starts to be too much sealed brood to make it reliable information. Much less and the mites/day count doesn't mean very much (i.e. there is too little dispersion).
7 days is about as long as I'd go before changing the board because, once they break cluster, you'll see increasing amounts of wax cappings, poop, varroa, etc on the board.

At this time of year, what drop threshold would lead you to treat ? I've been monitoring mine for the last 4 weeks, cleaning the board each week. There's some fine brood cappings on the boards so I know they are rearing small amounts of brood. As they are either in WBCs or poly hives they don't cluster strongly. 11/12 colonies have no drop but one is consistently dropping 5 mites per week. Wondering if I should treat & when?
Thanks

 

[drex]

Randy Oliver of scientific beekeeping has done lots of research and found it an effective format

 

[B+.]

The great Finman noted an interesting observation that a false reading can be had early in spring as lots of previously dead varroa haphazardly lodged in empty cells can be cleaned out to fall on your monitoring board.
If you do think you have a worrying varroa load maybe a good intervention at this time of year would be to "improve your hive hygiene" with some oxalic/glycerine strips from abelo.
https://www.abelo.co.uk/shop/varroa-control/oxalic-acid-strips/

Could you post a link to that assertion mbc?

 

[mbc]

Could you post a link to that assertion mbc?

Sorry no, just something he wrote that I mentally catalogued.
It'll be in the archive of this forum somewhere, heaven knows where to start searching, you could try a pm to the man himself.

 

[North End Bees]

Could you post a link to that assertion mbc?

https://beekeepingforum.co.uk/threads/what-varroa-treatment-for-early-spring.35939/#post-520380
Post #6

 

[mbc]

https://beekeepingforum.co.uk/threads/what-varroa-treatment-for-early-spring.35939/#post-520380
Post #6

Good work!

 

[B+.]

At this time of year, what drop threshold would lead you to treat ? I've been monitoring mine for the last 4 weeks, cleaning the board each week. There's some fine brood cappings on the boards so I know they are rearing small amounts of brood. As they are either in WBCs or poly hives they don't cluster strongly. 11/12 colonies have no drop but one is consistently dropping 5 mites per week. Wondering if I should treat & when?
Thanks

@elainemary You may not be aware that I work as part of the beebreed programme and am a member of the varroa management workgroup so I breed/test stock according to a standard protocol. Part of the testing protocol involves monitoring the development of varroa mite populations within a colony. Since I am interested in if/how the mite population develops, it would not serve my purpose to treat.
I have posted this chart before. it allows you to anticipate the varroa population and predict if/when the level will become so high that you should consider treatment. You may find this useful.

 

[B+.]

Good work!

Thank you mbc
It looks like Finman was referring to dead mites falling into cells following treatment during the reproductive cycle. That is different to monitoring natural mite drop at this time of year.

 

[jenkinsbrynmair]

Thank you mbc
It looks like Finman was referring to dead mites falling into cells following treatment during the reproductive cycle.

He was - and he's mentioned it a few times

 

[mbc]

Thank you mbc
It looks like Finman was referring to dead mites falling into cells following treatment during the reproductive cycle. That is different to monitoring natural mite drop at this time of year.

Agreed, you'll note the op had trickled in December.
I'd imagine this effect would be seen to a lesser extent with natural drop too.
Edit: not quite, iirc he was referring to mites knocked off during a winter bloodless trickle showing up months later when the bees got around to some house cleaning as the spring nest expands.

 

[B+.]

Agreed, you'll note the op had trickled in December.
I'd imagine this effect would be seen to a lesser extent with natural drop too.

Yes. Possibly so.
The natural mite drop is an estimate of the infestation at the start of a season (mites/day over at least a 3 week period) which allows the population growth to be measured as the season progresses. I would argue that measuring NMD immediately after treatment in the way Finman described means it isn't a natural mite drop. It's an artificially inflated figure.
I suppose it depends on whether the OPs cluster was carrying out it's normal cell cleaning behaviour or had gone into cluster during a cold period. I don't know what the weather has been like in Monmouthshire but here, in Bedfordshire, it's been a very mild "winter".

 

[elainemary]

@elainemary You may not be aware that I work as part of the beebreed programme and am a member of the varroa management workgroup so I breed/test stock according to a standard protocol. Part of the testing protocol involves monitoring the development of varroa mite populations within a colony. Since I am interested in if/how the mite population develops, it would not serve my purpose to treat.
I have posted this chart before. it allows you to anticipate the varroa population and predict if/when the level will become so high that you should consider treatment. You may find this useful.

Thankyou, that’s v helpful. Wasn’t fully aware of your background, sounds v interesting and rewarding work.