Scientists optimized how to grow large quantities of a beneficial fungus called Esteya vermicola in solid fermentation, which kills the pine wood nematode pest that destroys pine forests. By testing different combinations of ingredients (wheat bran, corn flour, soybean flour, glucose, yeast extract, and magnesium sulfate) and environmental conditions (temperature, humidity, inoculation volume, and time), researchers increased fungal spore production more than 4-fold. These results provide a practical method for producing biopesticide products to protect pine forests from this damaging pest.