Rosemary is a fragrant, woody perennial herb native to the Mediterranean. Like many fragrant herbs, rosemary is a member of the mint family, Lamiaceae. Until 2017, rosemary and closely related species were placed in the genus Rosmarinus, with common rosemary bearing the scientific name Rosmarinus officinalis. However, new genetic evidence led to the genus Rosmarinus being merged with the genus Salvia. Since 2017, common rosemary is known as Salvia rosmarinus.
Rosemary Essential Oil
Harnessing this powerful essential oil.
What is Rosemary?
Rosemary Oil and its Components
Rosemary is rich in fragrant oils, which give it its distinct smell and flavor. The primary components of rosemary are 1,8-cineole, alpha-pinene, and camphor, which can range in concentration from 30-60% of the total oil composition depending on the growing conditions and cultivar. Minor components of rosemary oil include beta-pinene, eucalyptol, and borneol, but there can be considerable variation.
While we mostly appreciate these oils when we’re cooking with rosemary, the plants evolved to produce these compounds for a very different purpose. Like many other fragrant, oil-rich plants, rosemary uses these oils to defend itself and deter herbivores. By extracting the essential oil of these plants, we can harness the power of these natural compounds. The essential oil of rosemary has been widely studied as an insecticide and antimicrobial agent, and is effective against numerous pests and pathogens. The components of rosemary act synergistically and penetrate the insect’s cuticle, disrupting physiological processes. This inhibits the pest’s normal growth and development. Rosemary oil and its components are effective both as contact insecticides and as fumigants.
Pest species which can be treated effectively with rosemary oil:
- Trichoplusia ni, the cabbage looper moth
- Ceratitis capitata, the Mediterranean fruit fly
- Plutella xylostella, the diamondback moth
- Tetranychus urticae, the red spider mite
- Pseudaletia unipuncta, the true armyworm moth
- Drosophila suzukii, the spotted wing drosophila
- Bemisia tabaci, the silverleaf whitefly
- Tribolium confusum, the confused flour beetle
- Callosobruchus maculatus, the cowpea weevil
- Brevicoryne brassicae, the cabbage aphid
- Aspergillus species
- Fusarium species
- Penicillium species
- Sitophilus oryzae, the rice weevil
- Tribolium castaneum, the red flour beetle
- Trogoderma granarium, the khapra beetle
- Orgyia trigotephras, the vapourer moth
- Ulomoides dermestoides, the Chinese weevil
- And many others!
Further Reading
Arshad, Z., Hanif, M. A., Qadri, R. W. K., and Khan, M. M. (2014). Role of essential oils in plant disease protection: A review. International Journal of Chemical and Biochemical Sciences.
Badreddine, B. S., Olfa, E., Samir, D., et al. (2015). Chemical composition of Rosmarinus and Lavandula essential oils and their insecticidal effects on Orygia trigotephras (Lepidoptera, Lymantriidae). Asian Pacific Journal of Tropical Medicine.
de Souza, M. T., de Souza, M. T., Bernardi, D., et al. (2022). Essential oil of Rosmarinus officinalis ecotypes and their major coompounds: Insecticidal and histological assessment against Drosophila suzukii and their impact on a nontarget parasitoid. Journal of Economic Entomology.
Isman, M. B. (2016). Pesticides based on plant essential oils: Phytochemical and practical considerations. American Chemical Society.
Isman, M. B., Wilson, J. A., and Bradbury, R. (2008). Insecticidal activities of commercial rosemary oils (Rosmarinus officinalis) against larvae of Pseudaletia unipuncta and Trichoplusia ni in relation to their chemical compositions. Pharmaceutical Biology.
Khalil, S., Zarrad, K., Hammouda, A. B., et al. (2015). Comparison between insecticide effects of wild and cultivated rosemary essential oils on stored product insects. Tunisian Journal of Plant Protection.
Koul, O., Walia, S., and Dhaliwal, G. S. (2008). Essential oils as green pesticides: Potential and constraints. Biopesticides International.
Krzyzowski, M., Baran, B., Lozowski, B., and Francikowski, J. (2020). The effect of Rosmarinus officinalis essential oil fumigation on biochemical, behavioral, and physiological parameters of Callosobruchus maculatus. Insects.
Mossa, A. -T. H. (2016). Green pesticides: Essential oils as biopesticides in insect-pest management. Journal of Environmental Science and Technology.
Park, Y. -L. And Tak, J. -H. (2016). Essential oils for arthropod pest management in agricultural production systems. In V. R. Preedy (Ed.), Essential Oils in Food Preservation, Flavor and Safety. Elsevier.
Pavela, R. (2006). Insecticidal activity of essential oils against cabbage aphid Brevicoryne brassicae. Journal of Essential Oil-Bearing Plants.
Raveau, R., Fontaine, J., and Sahraoui, A. L. -H. (2020). Essential oils as potential alternative biocontrol products against plant pathogens and weeds: A review. Foods.
Sener, O., Arslan, M., Demirel, N., and Uremis, I. (2009). Insecticidal effects of some essential oils against the confused flour beetle (Tribolium confusum du Val) (Col.: Tenebrinoidea) in stored wheat. Asian Journal of Chemistry.
Sertkaya, E., Kaya, K., and Soylu, S. (2010). Chemical compositions and insecticidal activities of the essential oils from several medicinal plants against the cotton whitefly, Bemisia tabaci. Asian Journal of Chemistry.
Shawer, R., El-Shazly, M. M., Khider, A. M., et al. (2022). Botanical oils isolated from Simmondsia chinensis and Rosmarinus officinalis cultivated in Northern Egypt: Chemical composition and insecticidal activity against Sitophilis oryzae (L.) and Tribolium castaneum (Herbst). Molecules.
Sil, A., Pramanik, K., Samantaray, P., Mondal, Md. F., and Yadav, V. (2020). Essential oils: A boon towards eco-friendly management of phytopathogenic fungi. Journal of Entomology and Zoology Studies.
Tak, J. -H. And Isman, M. B. (2015). Enhanced cuticular penetration as the mechanism for synergy of insecticidal constituents of rosemary essential oil in Trichoplusia ni. Scientific Reports.
