Hyperthermia is an alternative treatment method for theVarroa, which surpasses the negative side effects that common chemical products and acids have to the bees and the honey. It is based on the principles that 1) a combination of a specific temperature in a specific period of time can be proven harmful or fatal for any organism and 2) bees are more resistant than the Varroa to high temperatures. Any temperature higher than 40°C kills the Varroa in the brood (Engels 1998) and any temperature over 46-48°C kills the Varroa on the active bees (Harbo 2000). The brood shows resistance to temperatures up to 42°C and 43°C and the active bees can handle even higher ones.

Due to the different levels of resistibility between the brood and the active bees in high temperatures, the treatment was previously applied separately to the brood and to the active bees. This procedure was much more difficult and time consuming.

We, in our effort to apply bee-friendly methods that are harmless to humans, use hyperthermia since 1995 and we apply it directly to the hive without removing the brood. This experience led us to the creation of “Thermovar”, a device that is used to successfully treat the Varroa mite.

The device consists of three parts: the heat chamber, the hot air circulation conduit and the mite collection drawer.

It is applied in single hives, in colonies without any or with the least possible brood.

In order to adjust the heat chamber, we first remove the hive’s lid and we replace it a bee proof screen. Then we adjust the heat chamber on the top of the hive. Through the hot air circulation conduit, the heat chamber is connected with the mite collection drawer which is placed under a second bee proof screenat the bottom of the hive.

The whole system – hive, heat chamber, hot air circulation conduit and mite collection drawer – constitutes a closed air circuit. The only loss we have is a very small and controllable quantity of air that escapes from the small exit hole of the hot air circulation conduit and comes in from the entry hole of the mite collection drawer.

By putting into operation the heat chamber, the air inside the system starts to warm up gradually and with the help of the fan, it gets recycled as passes from the heat chamber to the circulation conduit, the drawer, the gaps between the honeycombs and ends back to the heat chamber. The device operates electronically, so that when the air reaches the desired temperature for the treatment, it remains stable for as long as we have set it up and it terminates the whole operation by itself.

Our experience so far, but also the experiments of other beekeepers and researchers at the university have led us to build three different electronic boards. Every beekeeper, depending on his/her practices, can choose a treatment with a different duration and temperatures.

Thermovar Model Temperature Duration of constant temperature Arming period of the timer
ST-1013 48.5 °C 13 min 30-40 min
ST-1006 42.0 °C 360 min 20-25 min
ST-1008 42.0 °C 480 min 20-25 min



Thermovar Model Varroa that fell from the bees Dead Varroa on the sealed brood
ST-1013 60-70 % 0-5 %
ST-1006 75-80 % * 93 %*
ST-1008 80-85 % * 100 % *

* Source: Apiculture Laboratory of the Aristotle University of Thessaloniki

The device as well as the method have been perfected in order to be effective and safe for the bees. During this process, however, we lost numerous bees and colonies and we wasted a lot of time and money.

In order to avoid someone making profit at our expense, we established proprietary rights over the method and the device with a Patent of Invention by the Industrial Property Organization in 2004.

If you are interested in using the device for the treatment of Varroa in your beehives, please contact us.


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