Bioactivity of aqueous extracts of Hedychium coronarium J. koenig on Spodoptera frugiperda J. e. Smith, 1797 (Lepidoptera: Noctuidae).
The aim of this study was to evaluate the insecticidal activity of aqueous extracts of root, rhizome, sheath and leaf of the plant Hedychium coronarium J. Koenig for 3rd instar's Spodoptera frugiperda caterpillars J.E. Smith, 1797, which is considered the main pest of corn in Brazil. The treatments consisted of aqueous extracts of the aforementioned plant parts, prepared in the concentration of 10% (w/v). As a control treatment, it was used distilled water. Cubes of 1 cm3 artificial diets were immersed in aqueous extracts and water for ten seconds and then caterpillars were offered. The characteristics evaluated were larval end pupal mass, survival and duration, adult insect mass end egg-adult biological cycle. The aqueous extracts obtained from the H. coronarium plant parts showed no toxicity to S. frugiperda. Contrary to what was expected, feeding was stimulated when the caterpillars were submitted to aqueous extract of leaves of this plant species, presenting larger larval mass and anticipation of the biological cycle.