Biological Control of Sitophilus zeamais in Stored Maize Using Beauveria bassiana

Background and Objective: The increasing demand for sustainable alternatives to chemical pesticides in grain storage has led to growing interest in biological control methods, particularly in developing countries where access to conventional pesticides is limited. This study aimed to evaluate the effectiveness of Beauveria bassiana as a biological control agent against Sitophilus zeamais, a major pest of stored maize. Materials and Methods: Beauveria bassiana was isolated from soil samples collected near oil palm trees in the Ashanti Region of Ghana. Laboratory bioassays were conducted to assess the efficacy of three conidial concentrations (2.0×10⁷ , 3.0×10⁷, and 4.0×10⁷ spores/mL) on adult S. zeamais over 7 Days under controlled conditions (27±2°C, 70±5% RH). Mortality rates were recorded daily, and data were analyzed using appropriate statistical tests to determine significance levels among treatments at p<0.05. Results: A concentration- and time-dependent response was observed. The highest conidial concentration (4.0×10⁷ spores/mL) caused 46% mortality of S. zeamais by Day 7. Statistical analysis confirmed significant differences between treatments during the final phase of the experiment (p = 0.006), demonstrating the increasing effectiveness of B. bassiana with higher dosages and exposure time. Conclusion: The study highlights the potential of B. bassiana as an effective biological control agent against S. zeamais in stored maize. This finding offers a promising alternative to chemical pesticides, especially in resource-limited settings. Further research is recommended to explore its application under field and storage conditions.