1. High larvicidal efficacy of yeast-encapsulated orange oil against Aedes aegypti strains from Brazil
- Author
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Monique Costa, Bruno Gomes, Fabiane Brant, Ademir Jesus Martins, Michael J. Workman, Mariana Rocha David, Ivy Hurwitz, Fernando A. Genta, Ravi Durvasula, Camila Jesus Pereira-Pinto, José Bento Pereira Lima, Huarlen Ogélio, and Marcelo Ramalho-Ortigao
- Subjects
0301 basic medicine ,Insecticides ,Veterinary medicine ,Mosquito Control ,Orange oil ,030231 tropical medicine ,Infectious and parasitic diseases ,RC109-216 ,Saccharomyces cerevisiae ,Aedes aegypti ,Dengue ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Aedes ,Pyrethrins ,Oils, Volatile ,Ultraviolet light ,Animals ,Plant Oils ,Larvicide ,Arbovirus ,Pyrethroid ,biology ,Research ,Environmental exposure ,biology.organism_classification ,Mosquito control ,030104 developmental biology ,Infectious Diseases ,Deltamethrin ,chemistry ,Larva ,Parasitology ,Brazil ,Temefos ,Citrus sinensis - Abstract
Background Botanical substances such as essential oils (EOs) have demonstrated insecticidal properties and are a valid option for vector control. However, free EOs are unreliable as mosquito larvicides due their easy degradation by environmental exposure to ultraviolet light and higher temperatures. Here, we assessed the efficacy of a mosquito larvicide based on orange oil in a yeast-based delivery system against Aedes aegypti strains with different resistance status towards chemical neurotoxic insecticides. This larvicide preparation was physicochemically characterized in a previous report. Methods Larvae of four Ae. aegypti strains from different regions of Brazil and different resistance profiles for deltamethrin (pyrethroid) and temephos (organophosphate) were tested against yeast-encapsulated orange oil (YEOO) in laboratory conditions for measurement of LC50 and LC90 values. The same assays were performed with the Belo Horizonte strain under environmental conditions (natural light and temperature). The resistance profiles of these strains were compared to the Rockefeller reference strain in all conditions. Results YEOO was found to be a highly active larvicide (LC50 Ae. aegypti strains tested in both laboratory conditions (LC50 = 8.1–24.7 mg/L) and environmental conditions with natural light and temperature fluctuation (LC50 = 20.0–49.9 mg/L). Moreover, all strains were considered susceptible (RR 90–95 of Belo Horizonte in the laboratory, probably due the higher heterogeneity associated with older egg papers (> 5 months). Conclusion YEOO demonstrates high larvicidal activity against Ae. aegypti strains with resistant phenotypes for deltamethrin (PY) and temephos (OP). This larvicidal activity suggests the potential for the development of YEOO as an alternative intervention to synthetic insecticides in integrated vector management programs, for populations with resistance to commonly used insecticides. Graphical Abstract
- Published
- 2021