Effect of systemic administration of essential oils and main components on honeybee survival

Controlling bee diseases with non contaminant products is a challenge in apicultural research. Essential oils and their main components have been widely studied as alternative treatments for honeybee pathologies [1, 2, 3]. However, there is little information about prolonged systemic administration. The aim of this study was to evaluate, in laboratory assays, the effect of long term consumption of essential oils and main components. Oils were obtained by hydrodistillation from Laurus nobilis, Cinnamomun zeylanicum, Origanum vulgare, Rosmarinus officinalis and Eucalyptus spp. and were analyzed by gas chromatography. The main components administered were 1,8-cineol, β-myrcene, cinnamic aldehyde, carvacrol and α-phellandrene. Substances were administered ad libitum to newly emerged bees at concentrations of 0; 333; 3,333 and 6,666 ppm, on sucrose syrup, throughout 11-18 days. Mortality and substances consumption were measured daily. Survival analysis was performed using Gehan-Breslow test and pairwise multiple comparisons between survival curves (a= 0, 05). Substances consumption was analyzed using one way ANOVA. Bees that received cinnamon oil showed a lower survival than control at concentrations higher than 333 ppm (pvalues<0.001 ). Consumption of cinnamic aldehyde, the main component of this oil (79.3%), also caused lower survival at the same concentrations (p-values