NZBF: What is an acceptable mite count in the weeks after putting varroa strips in a hive?

Welcome to NZ Beekeepers+
Would you like to join the rest of our members? Feel free to sign up today.
Sign up
5
2
Bay of Plenty
Experience
Hobbyist
I checked a sticky board four weeks after putting in 2 x apitraz strips (newly opened packet) and 2 x apivar (from a previously opened packet). Was surprised to find there were still 40+ mites on the board. Does this mean the treatment isn't working? Or does it mean the treatment is working because the mites are dying? We are told to keep checking mites after putting treatment in but it's hard to find any clear information on what is a normal mite count during this time. Not sure if I should be ok with that mite count or if I should panic. I am wondering now if the previously opened packet of apivar strips may no longer be effective. Perhaps I should put in 2 more of the newly opened apitraz.
 

Alastair

Founder Member
Platinum
8,785
9,993
Auckland
Experience
Semi Commercial
Was surprised to find there were still 40+ mites on the board. Does this mean the treatment isn't working?

No.

Or does it mean the treatment is working because the mites are dying?

That's not really the full answer either.

We are told to keep checking mites after putting treatment in but it's hard to find any clear information on what is a normal mite count during this time.

It depends on several factors, the main one being what the mite level was at the start of treatment.

However. Amitraz which is the active ingredient in both apivar and apitraz, kills mites slowly. Because it does not actually kill them direct, but causes them to become paralyzed so they eventually stop feeding and reproducing. This is unlike the fast acting pyrethroid based product that just quickly knocks the mites down.

So because the brood cycle is 3 weeks, it takes three weeks from the time treatment was placed until you should expect a reduction in the numbers of mites emerging with hatching brood. After that they are mostly being killed but some get to survive long enough to get back into a brood cell and reproduce. So they are reduced in number with each brood cycle but it takes several brood cycles to get mite numbers down to extremely low levels, which is why the strips should be left in a couple of months.

Like you I sometimes see alarming mite levels in hives after apivar has been in several weeks and it's easy to question if it's really working. But usually by the end of the full treatment period and for me i go the full 10 weeks, mite levels are near zero.

A few other things to consider. - The strips have to be placed correctly, ie, center of where the brood is, not the edge of the brood or the box, or you get poor results.
After that, amitraz is believed by some to not be working as well as it used to, although it is still the most reliable treatment we have.
Some beekeepers have reported problems with apitraz and now only use apivar if they decide to use an amitraz based product.
 
  • Agree
Reactions: John B
272
320
Gisborne Tairawhiti
Experience
Researcher
Good on you @KatJ for checking *during* the treatment, and not just assessing at the end. How long had the strips been opened for? Some will store previously opened strips sealed in the freezer but I think apivar can be used up to two weeks after opening. Apart from that . . .what @Alastair said 👆
 
5
2
Bay of Plenty
Experience
Hobbyist
Thank you for your replies. The Apivar strips were left over from last Autumn. I had resealed them and stored them in a cool, dark cupboard but I wonder if they were a bit old, they may have even expired. I don't have the packaging anymore to check that. I have put two more strips of Apitraz (opened in mid March) in the hive to make up for the Apivar being old. The Apitraz is a 10 pack and having only used 4 I suppose the rest won't be any good to keep for Autumn next year. The expiry date on the packet is June 2023.
 

Alastair

Founder Member
Platinum
8,785
9,993
Auckland
Experience
Semi Commercial
You can use old outdated strips, I do, just, it's a bit of a crap shoot knowing how much active ingredient they still have left.

But sounds like you have given them plenty, you clearly are monitoring, so it's just a case of giving things some more time, wait and see. You can monitor meantime, long as you have a downwards trend in mite numbers you know things are moving in the right direction.

Some folks think that apitraz releases the active ingredient very quickly then not enough at the end, so as you have apitraz strips close to expiry that need to be used, could be a good plan to put another 2 strips in 4 weeks after the other two.
 
5,764
6,323
canterbury
Experience
Commercial
I would suggest doing an alchohol wash ..... not for yourself, but for the mites. 200 bees in a shaker jar part filled with meths.
see what you get and report back.
 
350
450
Bay of Plenty
Experience
Commercial
Have you tried a varroa wash in Speights, @James ? “Yes IRD, I do about 10 alcohol washes every day and this is a legit business expense”
😀
Mmm flying back from OZ on Sunday, may have to stock up on ‘Jim Beam varroa elixir’ n ‘45south treatment fluid’.
Yes mr IRD man, after a few washes with these I can hardly see any varroa.
 

TSG

1
5
7992
Experience
Hobbyist
Thank you for your replies. The Apivar strips were left over from last Autumn. I had resealed them and stored them in a cool, dark cupboard but I wonder if they were a bit old, they may have even expired. I don't have the packaging anymore to check that. I have put two more strips of Apitraz (opened in mid March) in the hive to make up for the Apivar being old. The Apitraz is a 10 pack and having only used 4 I suppose the rest won't be any good to keep for Autumn next year. The expiry date on the packet is June 2023.
Hello - just a wee note. Opened packets of treatments (Apivar, Apitraz and Bayvarol) should be used up (or given to friends etc) Once opened the air activates the strips (which is why Apivar is vacuumed sealed and has a 2 year shelf life). Hence it is recommended that Apivar be used within a couple of weeks of opening. You will find similar instructions on the other treatments - as per the manufacturers recommendations. If you try to store opened packets, they will lose their effectiveness over time (regardless of the expiry date). This will impact on your hives. I know there are lots of beekeepers who freeze, re-vacuum packs etc, but ultimately the best option is to use or discard opened packets. Apivar now comes in a 60 pack, 12 pack and a 4 pack which is great for those who just have a few hives. Hope this helps and good luck.
 
445
327
Mid Canterbury
Experience
Semi Commercial
This will impact on your hives. I know there are lots of beekeepers who freeze, re-vacuum packs etc, but ultimately the best option is to use or discard opened packets.
Can't say that since varroa presentation in Mid Canterbury, I think in 2010, that this has been an issue for me. If I have had strips in an open packet left over, I wrap them in gladwrap, then tin foil, then snaplock bag, then freeze sometimes for 6 mths. In the past on reuse, these have been effective with 8 months between treatments, and I have been in an area with a lot of migratory beekeeping.
 

Alastair

Founder Member
Platinum
8,785
9,993
Auckland
Experience
Semi Commercial
I would somewhat agree with Maggie, the thing being to minimize the amount of oxygen the strips are exposed to. However the strips will not come out the same 6 months after the package was opened regardless how good you sealed them, there will be some degradation.

Now that strips come in 60 packs and I have less hives, it's a bigger amount in that last pack I need to store as safely as possible, or lose a couple hundred bucks.

But I've always stored the last opened pack and used them next season, cos mid winter checking you are always going to need a few here and there anyhow, so no point chucking them. If in doubt I may go 3 to a box instead of two, seems to work.
 
445
327
Mid Canterbury
Experience
Semi Commercial
The strips could probably be vacuum packed, instead of the way I did it. It was a tip I picked up pre Sth Is varroa, at a conference talk given by a couple of very reputable Nth Is beekeepers in the early 2000s, and filed at the back of my brain for when varroa arrived here. It suited and worked for me, but that doesn't mean it would work for everyone else's situation.
 


Top