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".
Etude des composés volatils du Vacherin fribourgeois et du Vacherin Mont-d`Or. (Study of the volatile compounds of Vacherin Fribourgeois and Vacherin Mont-d`Or cheeses).
Travaux Chimiques en Alimentation et Hygiène, 88, 1997, 233-258.
After a brief review of the literature dealing with Vacherin Fribourgeois and Vacherin Mont-d`Or (Swiss) cheese varieties, the results of a study of their neutral and alkaline volatile compounds are presented. These compounds were extracted using a dynamic headspace (purge & trap) method and separated by capillary gas chromatography. Qualitative and semi-quantitative determination (relative measurements) was carried out using mass selective detection and retention index. Eight Vacherin Fribourgeois and 9 Vacherin Mont-d`Or cheeses produced by well-known factories were analysed in duplicate. In total, 66 components were identified. The results are presented using descriptive statistics. Vacherin Mont-d`Or cheeses contained some terpenoids, probably due to packaging of the individual cheeses (approximately 500-1000 g) in wood (spruce). Four compounds (ethanol, alpha -pinene, ethyl caproate and alpha - terpineol) were sufficient for distinguishing between the 2 Vacherin cheese types with a coefficient of determination of r2 = 0.937. With the exception of terpenoids, most compounds identified were present in both cheese types, but frequently in different concentrations. All the compounds isolated had already been found in other Swiss and foreign cheese varieties
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.