Diet Composition Influences Growth Performance, Bioconversion of Black Soldier Fly Larvae: Agronomic Value and In Vitro Biofungicidal Activity of Derived Frass
Agronomy 2022, 12(8), 1765
Exuviae is today's $2 word. (Ex-ooo-vee-ay). Exuviae is the molted exoskeletons of insects, made up of nitrogen rich chitin. In nature, this material is colonized and decomposed by plant growth promoting bacteria. Some of the bacteria have been found to have anti-fungal effects.
In this study by Canadian scientists, we learn that microorganisms present in frass inhibited the growth of disease causing Alternaria, Botrytis, Rhizoctonia, and Fusarium. Furthermore, the feedstock given to the insects (Black Soldier Fly larvae in this instance) influenced the anti-fungal effects.
Two feedstocks were used, one known as the Gainsville House Fly Diet (mmmm)(a combination of 50% wheat bran, 30% alfalfa meal and 20% cornmeal), and the other diet being a food waste representative diet consisting of 39% fruits (5% pineapple, 2% cantaloupe, 7% orange, 3% apple, 2% grape, 2% strawberry, 7% bell pepper, 5% tomato, 2% lemon, 2% banana, and 2% pear), 36% vegetables (10% lettuce, 3% carrot, 3% cabbage, 2% onion, 3% leek, 3% celery, 3% broccoli, 2% cauliflower, 5% potato, and 2% corn), 15% bread, and 10% spent brewer’s grains. Which diet do you think gave us better anti-fungal action? We're guessing that you're guessing the more diverse food-waste diet. Well, you're right!!! Looks like it might be a good idea to get some frass in the mix. We recommend a top dress of 1/4 cup per square foot, scratched into the top inch or two, covered with a mulch, like straw or wood chips. Do this every couple weeks through the growing season for a healthy and vibrant garden.