Ensaio biológico com o fungo cultivado por atta sexdens sexdens (linneaus, 1758), (hymenoptera-formicidae)

Abstract

Alcoholic extracts of Sesamum indicum have already shown positive results inhibiting the growth of the symbiotic fungus of Atta sexdens rubropilosa ForreI (Pagnocca et al., 1990). In this work we studied Alta sexdens sexdens which is the predominant species in the Northern Region. The sauvae feed on fungus that is propagated from the crushing of leaves deposited in the anthill. For the inhibition test of this fungus, Sesamum indicum (sesame) oil, extracted from the seeds using chloroform and methanol as solvents, was used. The oil obtained was mixed to the Saboroud culture medium at different concentrations from 15 to 70 mg oil/ml medium before inoculation with the fungus. Growth was estimated by comparison with the control (culture medium without oil). Although contamination of the plates was observed 20 days after inoculation, a gradual decrease in the area of the fungus was observed as the concentration of oil in the culture medium increased. Some factors may have influenced the decrease in fungal area, such as number of inocula, contamination, and poorly selective culture medium.