The purpose of this study was to evaluate the larvicidal activity of essential oil (EO) microparticles of Melissa officinalis L. against Aedes aegypti. Leaves of M. officinalis were collected in the municipality of S?o Jos? de Ribamar, Maranh?o, Brazil, and then dried, crushed and milled. 90 g of dried leaves were used to obtain EO by the hydrodistillation method. All larvae showed mortality at all tested concentrations. The LC50 obtained for EO was...