The repellent efficacy of eleven essential oils against adult Dermacentor reticulatus ticks

Dermacentor reticulatus ticks are among the most important arthropod vectors of zoonotic disease agents in Europe. Eleven essential oils, namely basil (Ocimum basilicum), bergamot (Citrus bergamia), clove bud (Syzygium aromaticum), citronella (Cymbopogon winterianus), creeping thyme (Thymus serpyllum), lavender (Lavandula angustifolia), lemon-scented gum (Corymbia citriodora), marjoram (Origanum majorana), peppermint (Mentha piperita), spearmint (M. spicata), and red thyme (Thymus vulgaris) were tested for repellency against adult D. reticulatus ticks at concentrations of 1 and 3%. Clove bud, creeping thyme and red thyme essential oils were the most efficient - repelling 83, 82 and 68% of ticks when diluted to 3%, respectively. The mixture of creeping thyme and citronella containing 1.5% of each showed higher repellency (91%) than individual essential oils at the concentration of 3%.