Chemical Composition and Repellency of Essential Oils from Four Medicinal Plants Against Ixodes ricinus Nymphs (Acari: Ixodidae)

• Published in: Journal of medical entomology Vol. 49; no. 5; pp. 1067 - 1075
• Main Authors: El-Seedi, Hesham R, Khalil, Nasr S, Azeem, Muhammad, Taher, Eman A, Göransson, Ulf, Pålsson, Katinka, Borg-Karlson, Anna-Karin
• Format: Journal Article
• Language: English
• Published: England Entomological Society of America 01.09.2012
• Subjects: Animals; basil; bioassays; borneol; camphor; carvone; chemical composition; cineole; Egypt; essential oils; Gas Chromatography-Mass Spectrometry; Insect Repellents - isolation & purification; Ixodes; Ixodes ricinus; Lamiaceae - chemistry; leaves; linalool; medicinal plants; Mentha spicata; Nymph; nymphs; Ocimum basilicum; oils; Oils, Volatile - chemistry; Oils, Volatile - isolation & purification; Origanum majorana; Plants, Medicinal - chemistry; repellents; rosemary; Rosmarinus officinalis; steam distillation; ticks; Egypt
• ISSN: 0022-2585; 1938-2928
• DOI: 10.1603/ME11250

In our search for effective tick repellents from plant origin, we investigated the effect of essential oils of four medicinal and culinary plants belonging to the family Lamiaceae on nymphs of the tick Ixodesricinus (L.). The essential oils of the dry leaves of Rosmarinus officinalis (Rosemary) (L.), Mentha spicata (Spearmint) (L.), Origanum majorana (Majoram) (L.), and Ocimum basilicum (Basil) (L.) were isolated by steam distillation and 15 µg/cm² concentration of oils was tested against ticks in a laboratory bioassay. The oils of R. officinalis, M. spicata, and O. majorana showed strong repellency against the ticks 100, 93.2, and 84.3%, respectively, whereas O. basilicum only showed 64.5% repellency. When tested in the field, the oils of R. officinalis and M. spicata showed 68.3 and 59.4% repellency at a concentration of 6.5 µg/cm² on the test cloths. The oils were analyzed by gas chromatography mass spectrometry and the major compounds from the most repellent oils were 1,8-cineole, camphor, linalool, 4-terpineol, borneol, and carvone.