Why varroa treatment is not necessary with the ZEST hive
Counting varroa mites is interesting, but it does not rid you of them. That can be done if the hive design is both humid and well insulated as the ZEST is. If you change the hive environment by changing its design features you can be varroa treatment free. You just need to make an environment that reduces the varroa replacement value over each generation.
This is not so hard. Forget chemicals.
Honey bees in Cuba and South America have apparently learned to deal with it. The reason is likely to be that the climate is hot and humid. The question is how far north it will go in Australia where it is now resident. The propensity for varroa to die away in a humid hive was found out by accident when a laboratory hive was accidentally left at a higher humidity than others and that one lost its varroa. The precise mechanism of varroa destruction by high humidity remains a mystery. A standard bee hive entrance at the floor level with ventilation at the top causes a cooling stack (or flue) effect internally. This cools the hive in winter and takes away its humidity all year. The temperature difference in winter between inside and out is greater as is the ventilation, when it is not needed, but less so in the summer when it is.
Trickle top cross bee entry and ventilation in a beehive rather than bottom entry causes it to be more humid allowing a bucket of humidity to form and which also appears to be controllable by the bees, because when the outside ambient temperature falls at night the humidity rises by up to 20% points in a top entry hive. I invite you to try this. The only thing you have to lose is your varroa.
The propensity for varroa to die away in a warm hive is probably due to the time that a bee pupa takes to hatch which varies between 10 days (35C.) and 15 days (31C.) This depends on where it is in the brood nest. A highly insulated external hive envelope serves to keep the brood temperature up throughout the hive and over time, allowing the bees to hatch quicker and therefore the varroa to not have enough time to mature in the cells.
Winter in the UK is varroa breeding heaven, but insulation seems to confound them and reduces the winter stores consumption to about half, as a bonus. The DIY ZEST hive is made from aerated concrete blocks which have 39 times more Resistance (R) to the passage of heat than a thin walled wood hive has and appears consequently to be functionally free of varroa. Drift of bees carrying varroa from hives nearby that are not ZEST hives has been noticed.
Data logging hives comparison
We took data from the hives to understand the temperature and humidity. You will see that in the ZEST hive the temperature is regulated and therefore supports the bees health
The benefits of the ZEST system
There are many benefits to the ZEST hive and the patented frame system that compliments the design.
Firstly it is easy to put together and is much cheaper than alternative systems. The ZEST hive has been designed to have the least amount of maintenance and is valued by its users who have been able to compare this with other systems.
Due to its design, it ensures that the bees can regulate their temperature more easily, this, in turn, makes for happier bees, they are slower to swarm and are ultimately disease resistant as we know that alternative hive designs develop these diseases more easily. The design of the ZEST hive also ensures a robustness that many other designs simply can not offer and with recent changes in the weather and bigger storms, the ZEST hive will keep the bees safe all year round. The frame system has been designed so you have no need for fiddly and costly starter strips with a design that is long-lasting.
A community of beekeepers are valuing the ZEST design and also the discussions on how we can develop and support beekeeping for future generations. Why not join them.
OBSERVATIONS
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The ZEST hive has been shown to be functionally free of varroa for the last 10 years.
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I and other first adopters of the ZEST hive had treated against varroa in various ways.
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I had used thymol crystals in teabags and they seemed to work very well.
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First adopter Judy Challoner refused to treat until she had evidence that varroa was present in her ZEST hive.
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I checked on 2 consecutive Augusts and found none in her floor debris. This surprised me, but thought no more of it.
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I then visited Stuart Ferguson to do a late split, as well as a first ZEST adopter and a beginner. I did an inspection and cleared out the floor debris.
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Checking it for varroa we found none. This observation is rarely breached on any ZEST hive inspection
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I ceased my Thymol treatment and commenced to investigate the possible reasons for the ZEST being functionally free of varroa.
REASONINGS
Suspicion immediately fell upon the ZEST internal conditions (what else could it be) being both humid (proven to be anti varroa, but the precise reason is unknown) and highly insulated, unlike thin-walled hives. The insulating aerated concrete blocks the ZEST is made from also have a thermal "weight" that acts to even out the extremes of temperature over the day and night allowing the bees to more easily moderate the colony brood temperature to the optimum in the whole brood, and not just its centre.
If the resistance to the passage of heat (K value) for a traditional thin-walled wood hive is 1, that of a polystyrene hive is 3 and the ZEST hive is 39.
The pupating time of honey bees varies upon the temperature that the pupa are kept at, and can be up to 3 days longer if below 37.5 deg. environment.
A colder brood temperature gives the varroa longer to mature in the cells, allowing many more females to hatch and to overwhelm the colony.
All that is needed to become varroa-free is to suppress their replacement numbers to below "even" for each varroa generation which is easy in a ZEST.
CAVEATS
It was found that ZEST hives when no other type of hive is in the apiary, remain functionally free of varroa, but if alone in a mixed hive apiary will receive "drifters" that do carry varroa, but not to the point of being overwhelmed.
COMMENTS
The ZEST hive is benign in not just its suppression of varroa but to other maladies and common diseases such as Noseama and Acarine. It is unknown if it impacts AFB or EFB both being rare. It is not immune to CBPV. No reports of chalkbrood have been made. The ZEST uses about half of the winter stores that a thin-walled hive does.
Bill Summers