Our Thoughts on our Varroa Treatments
Well as per our blog post “Its Autumn in New Zealand – The Time to Treat is here“, over the last three weeks we’ve been treating all our hives. Our goal was to reduce the amount of varroa mites in the hives, going into the New Zealand winter.
We don't want too many mites going into winter. As the hive population decreases in a colony, a high number of mites will take over and you may lose that hive over the colder months.
Once your Varroa treatments are finished you need to check that your treatment worked as expected. Some treatments are dependent on the temperature to work. Some other treatments (such as Apistan) have been found not to work at all with some resistant mites.
Here is a breakdown of the days we did our Varroa Treatments:-
The Varroa treatments used were Oxalic acid crystals and Api Life Var
Well today is going to be full on, the morning started by adding Api life var to the four hives in the organic farm apiary. Did a full inspection on one hive, but will need to speed up if I am going to complete thirteen hives by the end of the day.
We are going doing to do around 40% of our hives with the Vaporiser, these are the hives with the kiwimana Meshboards, we put the vaporiser in the back so not to crush any bees in the process. The rest of the hives we are going to use Api Life Var. Which is a Thymol based product.
It was a bloody hot day and I managed to get four done before lunch time, this leaves with nine to do after lunch. The vaporiser ones should be much easier as I don’t need to open up the hives at all.
All completed but got a bad case of sun stroke in the process, so wasn’t feeling the best for a couple of days. Next week I must break up the sessions, but with the predicted rainfall this could prove difficult.
A rainy Day for Varroa Treatments
It had been predicted that Sunday was going to rain, so I started the treatments on Friday.
As it turns out the rain stated on Saturday instead, so I was doing treatments between the rain showers. Which made it interesting, some of the bees were not too happy about opening up their home just as the rain had stopped.
Sunday was raining all day, so it was great that we did all the hives over the last two days.
NZ Natural Beekeeping Conference
This was the weekend of the Natural Beekeeping Conference, so I only had one day to do all treatments. Which was challenge indeed, but I managed to do all hives in the one day.
I was proud of myself having done them all on one day, I must have got my technique down to a fine art.
Now we need to check the treatments have worked as expected. Watch this space, will be doing mite counts in the coming week and will report the results.
We counted the mite fall on four hives, these were all treated with the Vaporiser and Oxidic Acid. These were a result of a three day drop count. (ie. We placed a sticky board under the hive for three days, and then divide by three).
So the count is a average of the daily count of varroa mites falling out of the hive.
Here are results:-
Conclusion on our Varroa Treatments
Quoting the “Control of Varroa Book”:-
Autumn – Daily mite fall Greater than 20 mites per day. Colony collapse likely by end of season
All hives except “Swanson 1” are under or close to this threshold going into Winter, so I'm happy with the hives that were treated with the Oxidic Acid Vaporiser. We will have to look at why Swanson 1 has a higher count, and we may retreat this hive.
We need a way to check that our Varroa Treatments worked on the hives with Solid bottom boards, I need to investigate using a sugar shake method to check these hives.
This is the process where you gather 250 bees and add icing sugar to them and then count the resulting mites that fall off. I have never personally used this method, but I can see the benefit of getting a instant count. Especially on hives that you can't do a drop count to check your varroa treatments have indeed worked.
For a good breakdown of the treatments you can use is available here “A Review of Varroa Treatments in New Zealand“. This is put out by the Ministry for Primary Industries.
How to check if your mites are resistant to the the treatments you are using, a handy document by Dr R.M. Goodwin and H. M. McBrydie VARROA RESISTANCE
What about you?
How did you get on with your Varroa Treatments this Autumn, what did you use? Was it successful? Comment below I would love to hear how it went for you?