Larvicidal activity of oil-resin fractions from the Brazilian medicinal plant Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) against Aedes aegypti (Diptera, Culicidae) Atividade larvicida das frações do óleo-resina da planta medicinal brasileira Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) sobre o Aedes aegypti (Diptera, Culicidae)

Oil-resin fractions from Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) were evaluated for larvicidal activity on third larval instars of Aedes aegypti, in searching for alternative control methods for this mosquito. The bioactive fractions were chemically monitored by thinlayer chromatography, H and C nuclear magnetic resonance and mass spectrometry. Bioassays were performed using five repetitions, at a temperature of 28 ± 1°C, relative humidity of 80 ± 5% and light and dark cycles of 12h. Mortality was indicated by darkening of the cephalic capsule after 24h of exposure of the larvae to the solutions. The most active fractions were CRM 1-4 (sesquiterpenes) and CRM 5-7 (labdane diterpenes), which showed LC 50 values of 0.2 and 0.8ppm, respectively. Key-words: Copaifera reticulata. Aedes aegypti. Terpenoids. Larvicidal activity.