In the 1990s, the Bee Research Centre took part in a screening programme testing the potential effectiveness of over 100 essential oils and essential oil components against the varroa mite. Although sage, hyssop and thyme oils proved interesting, only thymol has been used in acaricide products. Thymol treatments require little effort, and there are a variety of preparations on the market. The advantages and drawbacks of thymol use are listed in the articles "Apilife VAR: A new varroacide with thymol as the main ingredient" and "THYMOVAR for Varroa control".
Somatic cell count (SCC) in milk is an essential indicator for defining and managing udder health. However, analyzing differential SCC (dSCC) can be helpful in determining the type or evolution stage of mastitis. A high abundance of polymorphonuclear cells (PMN) is associated with acute mastitis; however, the status of a chronic disease is less well characterized. A method capable of analyzing SCC and dSCC can prove to be a helpful tool for monitoring the status of evolution of mastitis disease in a better way. Therefore, a new direct-flow cytometry method was developed to count and differentiate somatic cells in milk without the steps of centrifugation or washing, avoiding variabilities that occur due to enrichment or loss of specific cell types. In this new method, SCC is analyzed using the method of DNA staining with Hoechst stain, whereas dSCC are analyzed using specific antibodies targeting 2 main cell types associated with mastitis: PMN cells and antigen-presenting cells, which are associated with innate and adaptive immunity. Equivalent SCC values were obtained between the new method and the routine ISO 13366-2 method in a comparison of 240 raw milk samples. Furthermore, dSCC results were confirmed by microscopy after May-Gründwald-Giemsa staining in 165 quarter milk samples from healthy and diseased cows. The method was verified with fluorescence microscopy on the 2 targeted cell types and in raw milk samples. The newly developed method is independent of any instrument and can be further designed to differentiate other cell types and animal species by selecting appropriate antibodies.
Although the use of thymol leads to residues in the wax and honey, these are negligible from a toxicological viewpoint. Since about 2008 the use of thymol-based products has been declining in Switzerland, and beekeepers making use of these products have tended to experience greater winter losses than those using e.g. formic acid.