Molluscicidal and mosquitocidal activities of the essential oils of Thymus capitatus L. and Marrubium vulgare L.
Molluscicidal activity of Thymus capitatus and Marrubium vulgare essential oils on adult and eggs of Biomphalaria alexandrina as well as on different stages of Culex pipiens was evaluated for their effectiveness on vector control. Steam distillation of essential oils of the flowering aerial parts of both Thymus capitatus L. and Marrubium vulgare L. yielded 0.5 and 0.2%, respectively. Results of GC/MS analyses of the two samples revealed an identified components in both oils amounted to 96.27 and 90.19% of the total oil composition for T, capitatus and M. vulgare, respectively. The two oil samples appeared dominated by the oxygenated constituents (88.22 and 57.50% for T. capitatus and M. vulgare, respectively). These were mainly composed of phenols among which carvacrol (32.98%) and thymol (32.82%) were the major constituents in T. capitatus oil while in M. vulgare oil, thymol (34.55%) was the major constituent. Borneol was present only in T. capitatus oil (9.15%). T. capitatus essential oil gave LC 50 and LC 90 mortality against adult snails at 200 and 400 ppm/3 h, respectively while that of Af. vulgare was 50 and 100 ppm/3 h, respectively. On the other hand, M. vulgare showed LC 100 ovicidal activity at 200 ppm/24 h while T. capitatus oil showed no ovicidal activity. Insecticidal activity of both two essential oils revealed LC 50 and LC 90 larvicidal activity at 100 and 200 ppm/12 h, respectively and LC 50 and LC 90 pupicidal activity at 200 and 400 ppm/12 h, respectively. Results of this study suggest that plant essential oils may have a promising role in vector control with needed continuing investigations. © 2012 Academic Journals Inc.
Salama, Maha M.; Taher, E. E.; and El Bahy, M. E., "Molluscicidal and mosquitocidal activities of the essential oils of Thymus capitatus L. and Marrubium vulgare L." (2012). Pharmacy. 452.