Beekeeping Practices – Varroa – 20th versus 21st Century

21st Century Beekeeping

In our view, it is now time to review OLD beekeeping practices.

Mostly in terms of how things have changed due to the appearance of the Varroa Destructor Mite (VDM).

The Varroa Destructor Mite (VDM)

It’s threat to the Honey Bee (Apis Melifera) in the 20th Century varroa caused such devastation.  Honey Bees sick and unable to recover and add to their troubles that the Beekeeper did not know how to deal with VDM presence in their hives.  Scientists were also on the back-foot in their knowledge and research conducted at that time was short time spans so long-term there was no reference for them.

The chemical companies created a ‘quick fix’.  This ‘quick-fix’ was made of plastic and chemical compounds.  Not cheap either. Oh and just know that these chemicals are harmful to humans and should not be used when honey supers are on a Beehive.  So it begs the question “how harmful is it to the Bees ?”

Anyway tangent….these chemical manufacturers presented their ‘quick-fix’ treatment along with their own short-term studies to show governmental authorities  – who then that this was the accepted method for dealing with the VDM.

Unfortunately… there were no long-term tests conducted before those “quick fixes” were introduced to the beekeepers so the real risk for the Honey Bee was not fully understood nor was the effects that these quick-fixes would have on the VDM itself.

One thing is fer sure, these chemical compounds were understood to cause resistence in the pest target, therefore the recommendation was to ‘rotate’ treatment products, which originally was another synthetic miticide.  So every beek followed these recommendations to treat with one treatment in Spring and a different one in Autumn.

So more costs involved for the beekeeper and more revenue for the chemical companies !

Interestingly…many herbicide spray chemicals were causing the target ‘weed’ to develop its cells’ to become ‘resistent’ to the herbicides, therefore they grew stronger, and then harder to kill.   Interestingly The result was that harsher chemicals were needed and so on and so forth it goes…so imagine what these chemical compounds would do to the cells in a VDM.

In reality the varroa specific chemical treatments which were approved by authorities, was made without true knowledge (at least we hope they had no knowledge of) of what the long-term consequences of what resistence would cause in the VDM and how much harm this would cause our Honey Bees.

We know with years of experience, the Varroa has caused the Honey Bee to become sick.  Their immune system becoming compromised then resulting in the whole colony becoming weak.  

With the drop in health of the Honey Bee – they no longer responded well to threats such as…

  • Moisture
  • Black Mould
  • Wasps
  • Cold

20th Century Beekeeping

Prior to the VDM…

…mould and moisture were not considered a real problem for a Beehive colony and advice from older beekeeper was  “...not to worry the bees will deal with it”… but unfortunately with the arrival of Varroa Destructor Mite this changed everything and dampness, mould and cold caused hives to start to fail.  Populations declined un-naturally so therefore entrance or guarding efforts weakened therefore pests could enter the Beehive with little challenge.

Beekeepers weren’t aware of what was going on in their Beehives. Beekeepers were not given enough information on how to tell when their hive was in trouble.  In many cases, often symptoms were picked-up too late and possibly misdiagnosed. Sac Brood often mistaken for AFB by new beeks.

The immune system of the Honey Bee is becoming undermined.  Not even scientists fully understood the massive harm the varroa would cause.

Until recently – it was understood that the VDM was similar to a tick that would feed on the blood of its prey, in Honey Bees it was their haemolymph (hemolymph) the VDM was feeding on.

*Bees have an open circulatory system, meaning that they do not have veins or arteries, but rather all their internal organs are bathed in a liquid called ‘hemolymph’ (a mix of blood and lymphatic fluid)

Page text and photos authored and Copyrighted to Zachary Huang, Dept. Entomology, Michigan State University.

We understand that this means that the VDM actually feed on the lymphatic fluid cells in the abdomen of the Honey Bee.

So the assumption is that through the feeding on those lymphatic cells, the varroa transfers viruses into those cells, which means the immune system becomes compromised which reduces the Bees ability to keep itself healthy.

Varroa destructor Mite (VDM) in drone cells

This is what happens to walking-bees.

Hatching Bee with deformed wings = Deformed Wing Virus (DWV)

And …oh wait …there’s more !!!

The other issue was that Beekeepers did not fully understand about was varroa in cells.  

Unaware the harm VDM would be causing inside the honey bee cells is truly a hard learning curve for many beekeepers.  

The simplistic explaination is that the natural instinct of the VDM ensures they enter the cells just before they were capped, where, inside the capped-cells, it does its worst damage !

Within the cells, under the capping, the female VDM lays its first egg which is male then mating would occur thereafter, resulting in production of females.  They then use the larvae as their food-source, feeding on the Honey Bee larvae.

Transference of viruses from the parent female VDM to the new offspring which would then transfer to the bee larvae.  The viruses causing ill-health, thus leading to developmental deformities in the growing larvae, these deformities appear (thus creating sickness rather than killing the larvae) results in the beekeeper seeing hatching bees with deformed wings.  


As explained in recent newsletters, the first job of a bee is to be a ‘nurse bee’.  The nurse bee if hatching with deformed wings, is actually infected with Deformed Wing Virus (DWV) therefore when it feeds the eggs or larvae in cells or does its cleaning duties is believed to spread the virus and infect larvae and where there are residues of VDM faeces left from hatchings, this is ‘processed’ by the nurse bees also.

Geez louise add to this…

…us kiwi beekeepers were faced with even more of a threat from the VDM, one that many European, American or Canadian beekeepers did not face ( and any countries that have below zero winters ).

This is the fact without those below zero temperatures and very temperate climes here in New Zealand ( and even in some South Island areas ) we kiwis are faced with year round foraging Bees.

The common thread was that kiwi beekeepers were only getting information through authorities that gained information from research conducted outside of New Zealand climatic conditions.

…which is ultimately not helpful to us !

So over the last 10 years of discoveries through losses, new learnings and beekeeping experiences –  we have come to understand Bee behaviour and how it impacts beehive management.

We began to understand that ‘towing the party line’ or taking advice from ‘generally distributed literature’ was not helping our bees but harming them.  

We have learnt that we needed to change from the old way of Spring / Autumn treating with synthetic miticides because of the resistance they have caused in the VDM ( this was announced at conference held in Hamilton since discovered in 2012 – heres the LINK )

We decided to create our own understanding and do our own field trials using organic treatments and using an integrated pest management program.

Results ?

Over time we have incurred hive losses due to the VDM, moreso in the last three Bee Seasons of 2014, 2015, 2016.

We have determined contributory losses caused by wasps was down to weakness of health and therefore inability for our girls to protect their hive.

Organic treatments appear to enhance bee behaviours such as cell cleaning, where our bees do not cap cells where larvae have varroa in them.  We have seen that Api Life Var continues to be great in encouraging grooming. We have seen all our hives get through last winter and go from strength to strength.  

So with the success we have pushed a little further with our testing, and that was not to treat as often but to focus more on monitoring mite levels and to observe how the bees cope with less OAV treatments, they appear to be coping better with moderate mite loads – whereas in previous summers, the colonies would have failed.

We also needed to shift our focus from one method to integrated pest management strategies which means using several methods to manage our Beehives.

The main result is that by using these organic methods and pest management tools / equipment the girls are stronger than ever.

We have also determined that the killing of queens seasonally only benefits those who sell queens, it appears logical that it stunts the honey Bees natural ability to adapt and enhance their bee behaviours.  Another consideration is that by buying in queens from outside of your local area would also stunt the natural ability and development of behaviours for that local area, which are enhanced only through surviving queens and their colonies of an area.

And for us kiwi beekeepers ?

…you need to know that if their Bees are foraging – they will be picking up mites !!  …if they are picking-up mites your colony is vulnerable to varroa IN CELLS !!!! if they are foraging year-round the old-fashioned way of treating Autumn / Spring will NOT be enough.

Conclusion ?

Monitoring VDM levels is crucial for all beeks – no matter what treatments you use.

Consider monitoring your number #1 jobbie.  Not just mite falls or from walking bees through sugar-shakes but checking inside capped cells in brood frames.

Checking for mites with Capping Scratcher

Treating if you find mite load increasing.

Warning:   Always do mite counts BEFORE treating.  Never use two treatment types at the same time, always complete treatments according to instructions and then wait to monitor results before using a different treatment. By monitoring mite levels about a week or two after treatments, will give you more accurate results on checking efficacy of the treatment rather than checking mite levels while treating – when you would always expect to see mite drops.  

Non invasive monitoring over Winter is as simple as having a meshboard with inspection tray – this sample below is a design and built meshboard by Gary at kiwimana.

Gary oiling the tops of the kiwimana meshboard
Kiwimana Meshboard – looking at the rear

The front looks like a normal baseboard but the picture shows the back of the meshboard.

You can see there is a corflute inspection board. This is a modern version of the old-fashion ‘sticky board’ reference.

Inspection Board Oiled used to check for Varroa Mites

Sticky boards were like a piece of cardboard and slid into the front of the Beehive, they were used to check for issues in a Beehive – the method is that you oil the board and anything that climbs in the hive will be captured on the sticky oil but unfortunately what it meant was that it would also ‘trap’ and kill honey bees too.

Sticky boards or inspection boards are so valuable for checking what is happening in a hive because waste, debris and varroa etc always fall down …..thanks to gravity ; ) but we don’t want to ‘trap’ our walking Bees !

  • Gary’s design of the base includes grooves on each side of the base, which the inspection board can slide into is set at height of 17mms under the mesh so would not interfere or kill any walking Honey bees. As the inspection board is accessed from the rear of the meshboard it means that the inspection board can be inserted / removed without you interfering with the flight-path of your Bees so they can just carry-on as usual.

The other very important benefit of Gary’s design is that you will not need to open the hive at all so is considered ‘non-invasive‘ which means you can access it any time of the year to do checks. This is great for checking varroa mite drops through Winter and also for any other issues such as robbing as it will catch wax-waste too. The beauty of the inspection board is that you won’t chill the hive, and you can remove if the weather is hot and then put it back in if there is heavy rainfall….

Do you have an Oxalic Acid Vaporizer ? then you can use this type of meshboard for OAV treatment application. The inspection board can be turned upside down, then add something to put the head of the vaporizer on to protect the corflute from the heat of the vaporizer head (otherwise it will melt it ! ) and a cloth to cover the entrance and the gap’s of the sides of the inspection board and bob’s your uncle !!

The OAV treatment application can be done any time of the year without being invasive as you won’t need to open the hive.

The mesh also enables the Bees to move air around the hive so they can ventilate and we have seen that it means that they don’t have to do fanning at the front entrance. The ability for the Bees to ventilate the hive means the girls can reduce moisture in the hive.

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