Effect of Alternative Rearing Substrates on the Growth, Reproduction and Nutritional Composition of the African Field Cricket Gyrllus bimaculatus (Orthoptera: Gryllidae)

Abstract

The increasing demand for animal protein to cater to the ever-growing human population has prompted the quest for alternative protein sources from insects. The field cricket Gyrllus bimaculatus, is one of the species of major interest, however, rearing of this species depends on the commercial chicken feed, which is expensive. This study explored the suitability of food remains in the rearing of this species. Three experimental food types were formulated from various food remains, and fed to crickets along with the commercial chicken feed for 14 weeks. Crickets that were fed on a combined diet of mixed food types performed better in terms of growth, biomass, and survivorship than their counterparts. Food types had a significant effect on the growth rate of the crickets, crickets that were fed on combined diet of mixed food types had the highest average weight of 405.70 ± 1.71 mg, whereas, crickets that were fed on the control diet had an average weight of 284.7±5.03 mg. Analysis of the nutritional composition of the harvested crickets yielded similar results of crude protein contents for crickets that were fed on control diet and combined diet with 54.70% and 50.70 % crude protein contents, respectively. Since the performance of crickets that were reared on locally available food remains was similar to the ones that were fed on a standard commercial diet, this simple diet presents a potential substrate for mass rearing of crickets which is cost-effective.