Summary
A new natural formula, Apedin Vapor^® (water, ethanol 19%, lactose and plant extracts: Echinacea angustifolia, Thuya occidentalis, Spiraea ulmaria and Oxalis acetosella) is considered a honeybee feed and an acaricide against Varroa mites. Colonies in apiaries in Northern Italy were sprayed with 50 ml of a 1:2 solution. After seven administrations at 19-28 day intervals (24 May-5 October 2002), acaricide efficacy reached 19.8%. In another trial, three doses at three-week intervals (the first on 18 May) were administered. Mite mortality was 54.1% and 22.6% in treated colonies and controls, respectively. A noticeable amount of parasites survived the treatment in both trials. The number of adult honeybees and brood cells in each colony were estimated according to the Liebefeld method (modified) before and after the treatment periods. No significant differences were recorded between treated and control groups in each trial. No external reaction to the treatment was detected. Small groups of bees were fed 60% sugar syrup, 60% sugar syrup and ethanol (19%), ethanol (19%), water, Apedin and a 1:2 solution of Apedin. The 60% syrup uptake was 81.5 mg/bee over a period of 28 h. The presence of ethanol seemed to considerably decrease the syrup palatability (the uptake was only 19.4 mg). 2.3 mg, 2.9 mg, 2.7 mg and 2.7 mg of water, ethanol, pure and diluted Apedin were removed, respectively and 84.6%, 80.0%, 71.4%, 74.5% of the bees were found dead or showed clear symptoms of starvation. Furthermore, respectively 0% and 37.5% of the bees in the groups fed plain syrup and syrup to which ethanol had added were dead or nonreactively lying on the bottom of the cages because of the insufficient feeding. The possible side effects of lactose as an Apedin Vapor^® component are discussed.

Keywords
Acaricide, Apis mellifera, Control, Varroa jacobsoni.