Hyptis brevipes (Lamiaceae) Extracts Strongly Inhibit the Growth and Development of Spodoptera littoralis (Boisd.) Larvae (Lepidoptera: Noctuidae)

Hyptis brevipes (Lamiaceae) extracts are shown to exhibit strong insecticidal activity against the 3rd instar larva of the cotton leaf worm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), inducing complete larval mortality due to the arrest and/or disruption of metamorphosis. This disruption induced a wide range of abnormalities. The LC50 value of the dichloromethane extract of H. brevipes was 3.0% (95% F.L. = 2.2% - 4.4%; slope = 3.185± 0.952) after three days of treatment. Two active compounds were isolated from the extract following bioassay-guided fractionation and were identified as 5-hydroxy-7,4'-dimethoxy-flavon-3-ol and 5-hydroxy-7-methoxy-2-(4`-methoxy-phenyl)-chromen-4-one based on spectroscopic data. This is the first report of these secondary metabolites in H. brevipes.