INSECTICIDAL ACTIVITY OF ESSENTIAL OIL OF Varronia curassavica Jacq. ABOUT LARVAE OF Aedes aegypti (DIPTERA: CULICIDAE).
Public health. Insect Vector. Botanical Insecticides. Essential oil.
The Aedes aegypti mosquito is of great interest in studies on arboviruses, due to the damage to public health as it is the main transmitter of dengue, chikungunya, yellow fever and Zika viruses. For years, this vector was restricted to some tropical regions and the viruses were endemic to them, but they are currently spreading to other subtropical and temperate regions. At this juncture, a continuous increase in the incidence of these arboviruses can be seen. Currently, there is an increase in investments to control the insect vector, but these measures are increasingly difficult due to the indiscriminate use of synthetic chemical insecticides which, although they are effective, are pollutants to the environment and their specific action does not only affect the organism. target, causing severe environmental and human health impacts. Therefore, botanical insecticides appear with the aim of reducing this damage. Therefore, with this research, we sought to evaluate the insecticidal effect of Varronia curassavica Jacq essential oil. (whale weed) on A. aegypti larvae. The methodological path of this research consisted of an exploratory study, of an experimental nature, a descriptive approach and quantitative analysis of the data obtained. The essential oil killed 100% of the larvae at the highest concentration (0.125%) within 24 hours. At 0.0625%, mortality varied between 77.5% in 24 hours, 96.3% in 48 hours and 100% in 72 hours. While the concentration 0.0312%, a result of 63.7% mortality was obtained in 24 hours and 90 and 95% in 48 and 72 hours, respectively. For the lowest concentration (0.0156%), mortality was 37.5, 51.2 and 25.5% at 24, 48 and 72 hours, respectively. In order to analyze the Lethal Concentrations, the LC10 was calculated, with a value of 0.003%, the LC50 of 0.014% and the LC90 of 0.031%, values that are considerably below the minimum, average and maximum concentrations of the oil tested. The main constituents found in Varronia curassavica oil were (E)-Caryophyllene, Bicyclogermacrene and δ-Cadinene, probably responsible for the mortality of Aedes aegypti larvae. The results demonstrate the insecticidal potential of V. curassavica essential oil in controlling A. aegypti, especially as this is unprecedented data for this plant species.