Functional and Quality Assessment of a Spore Harvester for Entomopathogenic Fungi for Biopesticide Production

The Green Revolution led to an increased use of synthetic pesticides, causing environmental pollution. As an alternative, biopesticides made from entomopathogenic agents such as fungi have been sought. This study aimed to design and evaluate the performance of a harvester machine for efficiently collecting entomopathogenic spores of Metarhizium anisopliae and Beauveria bassiana grown on rice and corn substrates. The spore yield was estimated, and a spore count and a colony-forming unit (CFU) count were performed. Statistical analysis was conducted to compare the mean values of spores obtained from different combinations of solid substrate and fungi. The Corn-Metarhizium combination produced 34.15 g of spores per kg of substrate and 1.51 × 10⁹ CFUs mL⁻¹. Similarly, the Rice-Metarhizium combination produced 57.35 g per kg and 1.59 × 10⁹ CFUs mL⁻¹. Meanwhile, the Corn-Beauveria combination yielded 35.47 g per kg and 1.00 × 10⁹ CFUs mL⁻¹, while the Rice-Beauveria combination had a yield of 38.26 g per kg and 4.50 × 10⁸ CFUs mL⁻¹. Based on the reported results, the Rice-Metarhizium combination appears to be the most effective, yielding the highest number of harvested spores per kg of substrate. The study estimated a total cost of approximately $409.31 for manufacturing the harvester, considering only the cost of the materials. These results could potentially increase the availability and affordability of entomopathogenic fungi in integrated pest management.