Controlling Varroa Mites

Varroa mites on Bees

As you know by now, the biggest threat and challenge that we face as beekeepers is the parasite  Varroa mite which vector many deadly viruses to our honey bees.

Varroa mites have  been very difficult to control despite few new products available to beekeepers, every so often. The latest  for us in the USA  is oxalic acid, although it has been used for many years in Europe and Canada! 

I do believe that first and foremost we should not treat our colonies if we do not have any V. mites. It is counter productive, it increases the resistance to medications, and it is costly. As I said in my previous blog, know your mite level. Monitor and sample your colonies.

What is IPM? 

Integrated Pest Management is an approach that is sensitive to the environment, and  where the beekeeper reduces  the reliance  of conventional or "hard" chemical treatments and incorporates multiple tactics to decrease  the incidence of pests and diseases, reducing the risk of chemical residues in honey and all hive products while maintaining sustainable treatment options. I teach this approach in my all beekeeping classes. I believe that this strategy makes sense.

IPM Pyramid

How to use this IPM Pyramid? 

1. Start with prevention: 

Choose  bees that are from mite-resistant stocks

ex: Russian, MN Hygienic, New World Carniolan or VSH (Varroa Sensitive Hygienic).

Choose your apiary site wisely

Maintain strong colonies with young fertile Queen

2. Cultural/Sanitation:

—Soil well drained, sunny, wind protection, H2O

—Feeding sugar water/ pollen supplement if needed

—Keep clean and healthy site

3. Physical/ Mechanical:

Using drone comb, one per brood box

Using screen bottom board (warmer climate, not recommended in MN)

Bee Protection Gate ( not yet on the market)--Made by Bayer Healthcare's Animal, Health Division.

4. Biological

Researchers are looking into manipulating the sexual behavior of V. mites, or using another insect to weaken the mites. A German company made a Bee-sauna, where every brood frame is steamed, dislodging and killing the mites! Maybe useful in the future for us, the beekeeper!

5. Chemical--Soft and Hard

Soft Chemicals (naturally occurring in nature)

Ex: Apiguard, (Thymol) ; Api Life (Thymol, eucalyptus, camphor)

Hop guard, (Hop)

Mite Away Quick II Strip, (Formic acid)--works well

Oxalic Acid--works well, just approved by EPA

Hard Chemicals  ( Developed in labs by scientists)

Ex: Apivar (Amitraz)--works

Apistan ( Fluvalinate) --accumulation in wax and possibly in honey, Varroa  resistance. I do not recommend.

Check Mite+ (Coumaphos)--accumulation in wax and  in honey, Varroa  resistance. I do not recommend.

NOTE

USE PESTICIDES AS A MEAN OF VERY LAST RESORT.
MITE-RESISTANT STOCK IS THE LONG TERM SOLUTION.

SINCE WE KNOW THAT MITES DEVELOP RESISTANCE EVENTUALLY TO ALL NEW CHEMICALS THAT WE CREATE...HONEY BEES WILL DEVELOP RESISTANCE TO MITES IN DUE TIME TOO.

However, I do believe that we need new "blood", new genetics to improve our American bee stocks. As  beekeepers, we help ourselves by dividing our best, healthy, populous and overwintered colonies. They already demonstrated that they are survivors, and that they are perfect for our own locality! I wish it would be that simple. 

Add your Honey Supers!

Colonies with supers on!

This week in Minnesota will be warm and perfect for our honey bees. They will go out and gather lots of nectar, and pollen. Make sure you are adding supers, so the bees have enough room to put their collection!

If not, your bees may leave the nest ... thinking there is no room! I usually place 2 supers at once because my hives are not in my own backyard. If the nectar flow is in full swing , the honey bees can fill up a super in a couple of days!

How do I know that there is a nectar flow?

You will notice many bees going in and out of the hive (foragers) from sun up to sun down.
If you look into your colony and remove some frames, you can see a lot of fresh nectar thetas uncapped.
If your super is "brand" new, you will see fresh white wax.

How do you put your supers on?

There are many ways to place your supers. I put my section honey super just above the brood nest, after the queen excluder, then I place a couple of supers on top of that. It is easy, and does not require any movement of honey supers. I don't like moving honey supers more than I need to.

Another way is to always put your new super on top of the last brood box; you will then have to remove your first super to place your second one, and so forth! Lots of effort...but it does not seem to make any difference in the amount of honey we will get.

Beautiful frame of capped honey

Ross round (section) being capped with honey

Left side: capped honey--Right side nectar

Are You Raising Varroa Mites?

4 Varroa mites on an adult honey bee

Do you know how many Varroa mites do you have in your colony? Are you treating, not knowing how many "ugly vampires" you have?

Varroa mites have a great impact on the health of the colony as a whole and on the honey bee itself. The mites feed on the bee's haemolymph (bee blood), as they pierce the bee's body, they transmit all kind of viral pathogens. Then the bee becomes weak, and cannot functioned properly, this affect not only the individual insect but the colony as a whole. If the Varroa mites are not under control, the hive will die within 2 years.

It is  a good practice to know your mites level early in the season, so the beekeeper can make an appropriate decision based on facts. Why would you treat your colony if your mite count is low? That is plan silly, and it encourages resistance to medications. TREAT ONLY IF NEEDED!

I like to have a baseline, so I can make the right decision about my colonies. Now  is the time to know your level of mite load.  I use 2 simple methods: Sticky Board OR Sugar Shake. Those 2 techniques are easy on both the bees and the beekeeper!

1. Sticky Board Method:    

     

Home made sticky board

Sticky board after 72 hours

I made my own sticky board, using a white poster board cut to fit the bottom of my boxes.  I cover the board with petroleum jelly using a thin and small paint roller. I then cut out a screen that I attached to the board with binder clips.

I slide the unit (board and screen) through the entrance of the hive onto the bottom board.

I leave it 72 hours. Not only the mites will be on that board but a lot of debris!

I remove it, and count ONLY the mites (reddish oval things!) Because I left it 72 hours, I have to divide my mite count by 3. This result gives me the mite load in 24 hours.  If you count 5-10 mites, you need to treat your  colony. This is called the threshold. Many options are available to decrease the number of mites. I will write about this topic, next time.

2. Sugar Shake, or Sugar Roll

I made my own using a preserving jar, and I cut out a 1/8 screen to fit the cover. The centre ring of the preserving jar is replaced with mesh that bees cannot fall through, but varroa mites can. You will need some confectioner sugar or icing sugar. A 1/2 cup measuring cup ( ~300 bee sample) to collect bees from frames, a white container or white paper plate and a spry bottle with plain water!

Homemade jars

The Process

1. Fill the  Jar with about 300 Bees. Collect bees from at least three brood frames, be sure not to collect the Queen by mistake.
2. Gently roll or shake the jar so  that ALL the  bees are coated with the icing sugar. 
3. Leave the bees for one minute in a shaded location.
4. Shake sugar and mites out of jar for around one minute, onto a white surface or plate. 
5. Spray water onto the sugar and mites in the white plate/ container. This dissolve the sugar, and  it is  much easier to see the mites.
6. Return bees to hive. They will groom themselves and will be fine.
7. If you have 3-4 mites, you will have to treat your colony.

Bees coated with sugar

Bees return to hive!

Mites onto white plate