Bioactivity of wild carrot (Daucus carota, Apiaceae) essential oil against mosquito larvae

Authors: Muturi, Ephantus; Doll, Kenneth - Ken; Ramirez, Jose; Rooney, Alejandro - Alex

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2018
Publication Date: 12/19/2018
Citation: Muturi, E.J., Doll, K.M., Ramirez, J.L., Rooney, A.P. 2018. Bioactivity of wild carrot (Daucus carota, Apiaceae) essential oil against mosquito larvae. Journal of Medical Entomology. https://doi.org/10.1093/jme/tjy226.
DOI: https://doi.org/10.1093/jme/tjy226

Interpretive Summary: Wild carrot also known as “Queen Anne’s Lace”, is a flowering plant in the family Apiaceae that is native to Europe and southwest Asia. This aggressively growing herb was introduced to the United States by European settlers and is now widespread across most of temperate North America. It invades disturbed dry prairies, abandoned fields and road sides and poses a significant threat to native species especially recovering grasslands. It is also a serious threat to domesticated carrot seed production due to unwanted hybridization/cross-pollination. In this study we show that essential oil of this invasive alien plant has moderate toxicity against larvae of the primary mosquito vectors of dengue and West Nile virus and could therefore be harnessed as a source of ecofriendly larvicides for mosquito control. These findings demonstrate the potential to manage this noxious invasive alien plant by exploiting its economic benefits.

Technical Abstract: Invasive alien plants wreak havoc on native ecosystems and using them as a source of biopesticides could improve their management. We examined the toxicity of essential oil of wild carrot (also known as ‘Queen Anne’s Lace’, Daucus carota Linnaeus), an aggressive invader throughout the United States, against Aedes aegypti L., Culex pipiens L., and Culex restuans Theobald larvae. Comparisons were made between essential oil extracted from umbels of local populations of wild carrot versus a commercial brand. Methyl isoeugenol (60.7%) was by far the most abundant constituent in commercial brand oil, whereas a-pinene (33.0%) and ß-pinene (25.8%) were the dominant constituents in essential oil extracted from local wild carrot populations. The commercial brand essential oil was significantly more toxic to Cx. restuans larvae (LC50 = 44.4 ppm) compared with Cx. pipiens (LC50 = 51.0 ppm) and Ae. aegypti (LC50 = 54.5 ppm). Essential oil from local populations of wild carrot was significantly more toxic to both Cx. pipiens (LC50 = 42.9) and Cx. restuans (LC50 = 40.3) larvae compared with Ae. aegypti (LC50 = 64.6 ppm) larvae. Three of the nine tested chemical constituents of wild carrot essential oil (terpinolene, para cymene, and '-terpinene) were consistently more toxic to larvae of the three mosquito species than the whole essential oil. These findings suggest that exploiting wild carrot essential oil and its chemical constituents as a biopesticide for mosquito control could be used as part of multifaceted approaches for controlling this invasive alien plant species.