Determination of LD50 and LT50 at Different Doses of <i>Beauveria bassiana </i>on <i>Cosmopolites sordidus</i>

Banana is a crop of global importance, both for its economic value and its role in food security. It is threatened by pests such as the banana weevil, which causes damage and can lead to considerable economic losses. Given the need to control this pest in a sustainable manner, the use of biopesticides, such as Beauveria bassiana, has been explored as an alternative to chemical pesticides. In this study, the pathogenicity of five isolates of this fungus was compared. Through the calculation of mean lethal doses (LD50) and mean lethal times (LT50), the efficacy of each isolate in pest insect mortality was determined. Statistical analysis was initiated from the mortality records obtained at 96 hours. The data were organized in an Excel table and subjected to normality and homogeneity of variance tests. Subsequently, an analysis of variance (ANOVA) was performed with InfoStat to compare treatments, and the differences between means were established by Tukey’s Test (p ≤ 0.05) the isolate that presented the highest virulence was BBT35 at 144 hours, followed by BBT31. The isolates evaluated showed different levels of effectiveness in controlling Cosmopolites sordidus. Some isolates were more effective at lower concentrations, while others required higher concentrations to achieve similar control. These results contribute to a better understanding of the interaction between the fungus and the fungus.