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".
Occurrence of volatile mono- and sesquiterpenoids in highland and lowland plant species as possible precursors for flavor compounds in milk and dairy products.
This paper examines the distribution of mono-and sesquiterpene secondary metabolites in 47 plants present in grazing areas from which cheeses are produced. In total, 54 terpenoid volatiles, derived from both highland and lowland plants, were obtained by a gaseous purge-and-trap system without the use of organic solvents and then identified by automated GC/MSD-FID analysis using mass spectral libraries, retention indices, and data acquired by the authors with authentic substances. Single ion monitoring proved valuable in identifying overlapping compounds with similar spectra for the subsequent semiquantitative determination of compositions. These are displayed as radar plots. It is suggested that flavor/aroma differences in cheeses produced from animals grazing in different areas and seasons arise from species (n = 38), phenological stages (n = 8), locations (n 4), and seasonal variation in terpenoids present (the most common were trans-beta-ocimene, limonene, and trans-beta-caryophyllene). This hypothesis is supported by the fact that distinct variations in terpenoids with differing odor descriptors and abundances were found., It is also possible that terpenes with a higher polarity are less efficiently recovered by the purge-and-trap method than compounds of lower polarity. As the radar plots display relative concentrations based on detection limits, the relative efficiency of detection for different classes of compounds needs to be taken into consideration
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.