Professor University of Wisconsin Madison, Wisconsin
Insect agriculture is a set of practices with potential to improve nutritional access in many areas of the world, but reliable low-cost feeds are needed. Here, we explore the potential to modify corn crop residue with edible mushroom mycelium to generate a feed adjunct for edible Gryllus bimaculatus. Like insect agriculture, mushroom farming is versatile; it can yield nutritious food while increasing system circularity by using lignocellulosic residues from row crops as inputs. The oyster mushroom, Pleurotus ostreatus, is a basidiomycete widely cultivated on corn stover (Zea mays). Mushroom harvest results in abundant “spent” substrate, which we investigated as a low-cost cricket feed adjunct. Across two feed trials, we measured cricket growth performance for six feed fermentation durations, two fruiting induction conditions, and three unfermented controls, testing impacts of fungal fermentation length and induced mushroom formation. Pasteurized corn stover was inoculated with P. ostreatus mycelium and fermented for lengths between 1 and 8 weeks. Some 4 and 8-week substrates were selectively induced to produce mushrooms. Dried fermented stover (40%) was added to a 1:1 corn/soy grain mix and fed to crickets ad libitum for 44 days. Cricket mass, mortality, and maturation were measured weekly. The unfermented control group showed higher survivorship compared to several fermented diets. Total mass yield was 16.5±10.7% higher in crickets fed unfermented diet than the combined mean for all fermented diets. In a subsequent experiment we confirmed that 50% P. ostreatus-fermented stover in feedhad strong negative effects on cricket growth performance compared to unfermented control.