Essential oils of Labiatae for controlling honey bee varroosis

The efficiency of Labiatae essential oils was compared with a classical aerosol treatment, including the acaricidic substance amitraz at the 0.25 concentration. The tested concentrations of the experimental mixture were 1% of thyme (Thymus vulgaris L.) and 0.5% of sage (Salvia officinalis L.). These products were also injected into each colony by the aerosol way for one minute. 4 applications in an interval of 3 or 4 cays constitute the treatment. The dead mites (Varroa jacobsoni Oud.) were counted everyday. The number of surviving mites was estimated by means of a fluvalinate control treatment. No difference in the global efficiency was found for the moderately infested colonies (less than 1300 mites, a few mutilated pupae), which contained a small brood area. A weak grade of post-therapeutic residues in honey was only detected by gas chromatography just after aerosol administration