Do bees put holes in the propolis layer on purpose to achieve the effect of functional clothing?
Torben Schiffer says so. He presents in the name of HOBOS electron microscopic images of holes in the propolis layer online among a theory of their formation and effect. It is stated that bees create these holes on purpose to ensure the removal of moisture by water vapor diffusion. Supposedly, they achieve an effect such as that of functional clothing (like Gore-Tex) by this means that allows water vapor diffusion but prevents the permeability to water in its liquid form. Several questions arise from the article. Continue reading “Theory of Torben Schiffer on the propolis of bees”
In the last weeks I spent a lot of time to upgrade my system for recording infrared videos. I replaced the old 0.4MP camera with a 3MP camera with a wide-angle lens. The illumination is now via 9 infrared LEDs (previously one LED) and is now recorded at a frame rate of 60fps (previously 25fps). Continue reading “Upgrade of the Infrared Camera System”
A balance is established between the water content of the honey and the surrounding air humidity. The balancing moisture content of honey at a relative humidity of 55% is about 17.5%. At a relative humidity of 80%, honey has a water content of over 30% (source: The hygroscopic properties of different dilutions of Honey, Doull & Mew 1977).
The evolution of honeybees has taken place over many millions of years in tree hollows with a respectable thermal insulation of the surrounding wood. It is to be expected that they have adjusted perfectly to this climate inside the tree caves, which is much influenced by the thermal insulation. Only in modern beekeeping did they have to forgo the advantages of such thermal insulation. Continue reading “Effect of outer thermal insulation on moisture in the beehive”
In the fall of 2017, I made Thomas Seeley an offer he couldn’t possibly refuse. I offered him 10 of my just finished Beeloggers to use in the Arnot Forest in the natural tree caves he knows. I wrote him an e-mail with all the information about the data loggers and offered to climb into the trees with him. Thomas Seeley answered quickly and firmly: Unfortunately no time. Continue reading “Tom´s Tree”
A bee tries to free itself from a Varroa mite for minutes, with powerful and very fast shaking movements. Presumably she cannot distinguish the mite from disturbing pollen residues at all, I have often been able to observe this shaking movements. Continue reading “Rodeo bee drops Varroa mite!”
In December 2017 I took measurements on a beehive with a Diffusion-lid for 2 weeks to get an overview of the average temperature below the lid. For this purpose, 7 temperature sensors were installed as shown. The values given are the average temperature difference between the sensor and the outdoor temperature. The average temperature difference to the outside air is 5.5°C in the 2 weeks considered (the average outside temperature in the period was 0.4°C). The temperature difference is much smaller than expected, especially since the hive is provided with an additional external insulation, a closed floor and only 3 small entrances. But the bees do not heat the hive, but only their bee cluster :-).
Because of this rather small temperature difference, I had some doubts if I was right with my theories…
When considering the thermal insulation of bee hives, we also have to consider the honeycomb construction with its air layers in between. These layers themselves act as thermal insulation. The more honeycombs between the bee cluster and the side wall, the higher the insulation. I.e. with regard to the side thermal insulation, the broad constructions of the modern hives are quite helpful. Continue reading “Thermal insulation of honeycombs”
Almost 100 years ago, straw hives with frames were already used for beekeeping. The hive has a wooden bottom, the entrance hole is only a small slit, the side walls are made of straw and the lid is a double-walled wooden construction with straw filling. In these hives there were no problems with mould and condensation, although the lid construction is not highly vapour permeable. The construction demonstrates that humidity can also be carried away through the side walls by diffusion. Further information under Diffusion and D-cover.