The Effects of Trichilia claussenii Extract on the Efficacy of Entomopathogenic Fungi Produced by Submerged Fermentation

The search for sustainable pest management alternatives has intensified due to the risks of chemical pesticides. Entomopathogenic fungi and plant extracts, rich in insecticidal secondary metabolites, are among the most promising approaches. Integrating these agents can enhance complementary mechanisms and reduce environmental impact. This study evaluated the insecticidal potential of fungi produced by submerged fermentation (Beauveria bassiana, Metarhizium anisopliae, Trichoderma asperelloides, Isaria javanica, and Cordyceps fumosorosea) applied alone and combined with Trichilia claussenii extract against Euschistus heros and Spodoptera frugiperda. Fermentation showed good fungal adaptation and high sporulation, especially B. bassiana (8.33 × 108 spores mL−1) and T. asperelloides (9.42 × 107 spores mL−1). Adding the plant extract increased colony-forming units, notably for M. anisopliae (7.40 × 107 CFU mL−1) and B. bassiana (1.55 × 108 CFU mL−1). In bioassays, cell suspensions were more effective than isolated metabolites, reaching 97.8% mortality for E. heros and 91.5% for S. frugiperda with B. bassiana plus extract. These results indicate that combining entomopathogenic fungi with T. claussenii extract is a promising strategy for developing efficient and sustainable biopesticides, contributing directly to integrated pest management practices with reduced environmental impact.