This study investigated the effectiveness of two entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, against different life stages of Trilocha varians. The results demonstrated a higher mortality rate of eggs at increased conidial concentrations, with M. anisopliae and B. bassiana causing 37.42% and 33.39% egg mortality, respectively, at a concentration of 2 × 10⁶ conidia/mL. Mortality of 2^nd instar larvae increased over time, reaching 49.53% for M. anisopliae and 55.51% for B. bassiana after 120 hours of exposure. These findings highlight that while both fungi exhibit substantial lethality against T. varians, B. bassiana is slightly more effective, particularly in reducing the pest population over a shorter duration. The study also revealed that the effectiveness of the fungi decreased as the larvae develop, with 3^rd instar larvae showing greater resistance. This reduced susceptibility is likely due to the biological and physiological changes that occur as larvae progress through their life stages, such as reduced feeding rates and enhanced metabolic defences. Overall, the study underscores the potential of M. anisopliae and B. bassiana as biopesticides, with B. bassiana showing a faster mode of action, making it a more potent option for controlling T. varians populations.