Efficacy of Carum carvi essential oil against the parasitic varroa mite and its impact on honeybee Apis mellifera L.

Abstract

The Caraway, Carum carvi essential oil was assessed to behave as natural control of bee parasitic mite, Varroa destructor during fall season instead of chemicals methods. Caraway oil (100%) was used and compared to the synthetic acaricide; Apistan. The number of fallen mites and infestation percentages on both adult and brood were estimated regarding the effects of essential oil on honeybees Apis mellifera. The essential oil from C. carvi seeds were extracted by hydro distillation and characterized by GC/MS. Sixteen compounds were identified representing; 97.33% of the oil. The predominant components were Limonene (38.81%), Carvone (35.43 %), α-Myrcene (7.3%), Dihydrocarvone (5.58%) and Limonene oxide (5.13%). The infestation reduction percentages, recorded with Caraway oil, reached 84.42% and 70.65% on adult and brood workers after 21 days of treatments with no statistical difference with Apistan. The mean numbers of fallen Varroa mites were (67.67) and (74.65) in hives treated by essential oil and Apistan, respectively. The immune response of honeybee workers and pupa revealed significant elevation in phenol oxidase activity with Caraway oil however, remarkable inhibition in the enzyme activity observed with workers exposed to Apistan. The comet assay performed on worker honeybee as a biomarker of DNA damage; revealed statistically significant increase in DNA damage caused with Apistan (20.1%) and infested bee (21.64 %) compared to corresponding one treated with Caraway essential oil (12.4%) and control (9.6%). Caraway essential oil proved a safe way as natural controlling of Varoaa destructive with keep guard of honeybee social life and fit into IPM programs