RESUMO
Mosquitoes of the Aedes genus are responsible for transmitting many vector-borne viral diseases worldwide. Hundreds of thousands of people die annually from vector-borne diseases, including West Nile fever, dengue, tick-borne diseases, yellow fever, chikungunya, Rift Valley fever, and Zika. Billions of people are at the risk of infection on all continents, which is a cause of international concern. Therefore, new vector-control methods are essential for mitigating these illnesses. The bioactive hydrocarbons isolated from Xylopia langsdorfiana St. Hilaire & Tulasne are trachylobanes, a rare class of diterpenes found in the n-hexane fraction of the stem and leaf ethanolic extracts. These were tested against Ae. aegypti fourth-instar larvae over 48 h of exposure, with LC50 values ranging from 19.84 to 72.9 µg/mL, comparable to that of the positive control. The findings highlight the potential of Xylopia langsdorfiana St. Hilaire & Tulasne metabolites for controlling the main vectors of arthropod-borne viruses.
RESUMO
PURPOSE: Rhipicephalus (Boophilus) microplus is one the most significant ectoparasite in cattle farming in tropical and subtropical regions, causing problems to livestock health worldwide. The control of this ectoparasite primarily relies on the use of synthetic acaricides. However, the emergence of acaricide resistance has stimulated the search for new control alternatives, including phytocompounds with acaricidal and insecticidal potential. The aim of this study was to evaluate the acaricidal potential of Lavandula dentata essential oil against the engorged females of R. (B.) microplus. METHODS: Engorged females were obtained from infested bovines in dairy farms in Pernambuco, Brazil. L. dentata essential oil was extracted, and adult immersion test assays were performed using the following oil concentrations: 0.2%, 0.4%, 0.6%, 0.8%, and 1%. RESULTS: L. dentata essential oil at a concentration of 1% was lethal to all engorged females, and concentrations of 0.6% and 0.8% caused mortality of 98.6% and 99.1%, respectively. These concentrations disrupted the reproductive capacity of engorged females, reducing oviposition by more than 90% and preventing egg hatching by over 87%. CONCLUSION: The data revealed that L. dentata essential oil possesses effective pharmacological properties against R. (B.) microplus and could be used for tick control following in vivo evaluation, thus contributing to mitigating the negative impacts of synthetic acaricide use.