Opsiphanes cassina is the most common defoliating pest in the country’s commercial oil palm plantations, being responsible for low yields and the disappearance of large numbers of hectares of cultivation. The objective of this work was to evaluate in laboratory the invasive capacity of two formulations (powder and liquid presentation) based on Beauveria bassiana on the insect Opsiphanes cassina.Microbiological quality control tests showed germination percentages of B. bassiana spores for the solid formulation of 90% while in the liquid they were 97.7%. 100% purity was achieved for both formulations and the concentration of spores was 4.9x1010 spores/ml in the solid formulation and 8.6x1010 spores/ml in the liquid formulation. Concluding that the liquid formulation causes greater mortality in a smaller time (6 days) on the larvae of the III instar, being feasible its production and commercialization.