Biological activity of selected Lamiaceae and Zingiberaceae plant essential oils against the dengue vector Aedes aegypti L. (Diptera: Culicidae).

The larvicidal activity of hydrodistillate extracts from Mentha piperita L. Ocimum basilicum L. Curcuma longa L. and Zingiber officinale L. were investigated against the dengue vector Aedes aegypti L. (Diptera: Culicidae).The results indicated that the mortality rates at 80, 100, 200 and 400 ppm of M. piperita, Z. officinale, C. longa and O. basilicum concentrations were highest amongst all concentrations of the crude extracts tested against all the larval instars and pupae of A. aegypti. Result of log probit analysis (at 95% confidence level) revealed that lethal concentration LC₅₀ and LC₉₀ values were 47.54 and 86.54 ppm for M. piperita, 40.5 and 85.53 ppm for Z. officinale, 115.6 and 193.3 ppm for C. longa and 148.5 and 325.7 ppm for O. basilicum, respectively. All of the tested oils proved to have strong larvicidal activity (doses from 5 to 350 ppm) against A. aegypti fourth instars, with the most potent oil being M. piperita extract, followed by Z. officinale, C. longa and O. basilicum. In general, early instars were more susceptible than the late instars and pupae. The results achieved suggest that, in addition to their medicinal activities, Lamiaceae and Zingiberaceae plant extracts may also serve as a natural larvicidal agent.