AUTHOR=Margaret Kababu , Collins Mweresa K. , Subramanian Sevgan , Egonyu James P. , Nakimbugwe Dorothy , Ssepuuya Geoffrey , Faith Nyamu , Ekesi Sunday , Tanga Chrysantus M. 

TITLE=Innovative feedstocks for optimal mass production of the edible long-horned grasshopper, Ruspolia differens

JOURNAL=Frontiers in Physiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.1015636

DOI=10.3389/fphys.2022.1015636

ISSN=1664-042X

ABSTRACT=The edible long-horned grasshopper Ruspolia differens Serville (Orthoptera:Tettigonidae) is a highly nutritious food source consumed in over 20 African countries. Its occurrence is highly seasonal and wild harvesting is carried out using locally designed and inefficient light trap, thus limiting sustainable utilization as an important food source. To ensure year-round production and availability of R. differens, we evaluated the effects of low-cost and affordable diets based on agricultural byproducts on their growth performance, survival, fecundity and longevity. Four diets with varying ratios of agricultural byproducts: diet 1 [33.3% maize bran (MB) + 33.3% wheat bran (WB) + 33.3% Moringa oleifera leaf powder (MOLP)], diet 2 [25% MB + 25% WB + 25% MOLP + 25% shrimp powder (SP)] and diet 3 [20% MB + 20% WB + 20% MOLP + 20% SP + 20% soya bean meal] and diet 4 (“control” – routinely used diet) were evaluated. The grasshoppers were subjected to the diets from the 1st nymphal instar (24 hrs -old stages) through adult stages till death. Diet 3 had the highest crude protein content (28%) and digestibility (74.7%). R. differens fed diet 3 had the shortest development time (57 days) [p < 0.001], highest survival (87%) [p < 0.001], highest longevity (89 days) [p= 0.015] and fecundity (247 eggs/female) [p = 0.549] across the various diets. Female survival rate (59%) on diet 3 was significantly higher compared to the males (41%). The adult female weight gain was significantly higher compared to males fed on different diets. Percentage hatchability of eggs was not significantly different when females were fed on diet 3 and diet 2. There was a significantly positive correlation between longevity and fecundity of R. differens reared on diet 2 and 3. These diets could be further optimized and finetuned for improved cost-effective mass production of R. differens continent-wide to reduce dependence on erratic and poor seasonal harvest during swarms.