Essential oils toxicity related to Varroa destructor and Apis mellifera under laboratory conditions

摘要

Acaricidal effect of Tagetes minuta , Heterotheca latifolia , and Eucaliptus sp. essential oils against Varroa destructor and their toxicity for Apis mellifera L. were evaluated under laboratory conditions in two assays. In the first experiment, 10 mg of plant active principles were prepared in water solution with an emulsionant at 3, 4, and 5% concentrations. For each component and to each dose, 10 females V. destructor were pulverized in a Burgerjon tower and transferred to a Petri dish with 5 bee pupae to an incubation stove at 70% RH and 33-34C for 3 days. Dead and alive mites were counted 12, 24, and 48 h after treatment for five replications and their controls. No significant differences were found among doses of the same component and its effectiveness varied between 63 to 84% related to the control groups. In the second assay, 100 adult bees were pulverized with 10 mg of a 5% solution of the components and placed in an incubator stove at 70% RH and 33-34C. Four replications and a control treatment for each sample were taken simultaneously. Dead and alive bees for each replication were counted 72 h post-treatments. There were not significant differences in bee mortality among the control groups (P>0.05) and it was relatively low for all treatments except for eucalyptol in which the bee mortality percentage was higher than 58%. It was concluded that T. minuta and H. latifolia essential oils can play an important role in an integrated pest management program to control Varroosis in honey bee colonies.