Mosquitoes are a major concern to human health because they serve as vectors to pass agents that cause diseases, such as malaria, the Zika virus, and the West Nile virus, which can have a multitude of harmful side effects, such as seizures, conjunctivitis, and death. The overuse of commercial mosquitocidal agents have caused mosquitoes to develop resistance and cause harm to humans and the environment. To prevent this, natural extracts could be used. The purpose of this experiment was to test various plant extracts for their effectiveness in acting as larvicides, adulticides, and repellents against Culex quinquefasciatus mosquitoes. It was hypothesized that if Chrysanthemum coccineum (Persian chrysanthemum), Trachyspermum ammi (ajwain), Nymphaea odorata (American water lily), and common commercial products such as VectoBac 12AS, permethrin, and DEET were tested as natural adulticides, larvicides, and repellents, the commercial products and T. ammi would be the most effective, followed by C. coccineum and N. odorata. For the purpose of this experiment, the essential oils from the leaves of C. coccineum, T. ammi, and N. odorata were extracted, and the extracts and commercial products were tested on larvae and adult Culex mosquitoes as larvicides, adulticides and repellents. Various statistical tests were conducted, and it was found that for the larvicide and adulticide, T. ammi, VectoBac 12AS, and permethrin were the most effective, and for the repellent, all the treatments were effective, thus supporting the hypothesis. While the chrysanthemum and lily work only as repellents, ajwain works as effectively as commercial larvicides, adulticides and repellents, with the advantage of being a single product that reduces and repels two life stages of the mosquito. Since these plants are found in third world countries, these natural extracts could be used by natives or refined by local companies to create an inexpensive mosquitocide and repellent.
"Novel Mosquito Control: A Natural Approach to Reducing and Repelling Mosquito Populations,"
Journal of the South Carolina Academy of Science: Vol. 15:
2, Article 11.
Available at: https://scholarcommons.sc.edu/jscas/vol15/iss2/11