Prospects of rearing selected southern African swarming insects for animal feed: a review on insect farming and the economic value of edible insects

The potential of insects as animal feed is currently under doubtful spotlight due to the limited number of reared insect species and fewer farm or biotechnological companies producing insects on a large scale for animal feed worldwide. Again, the costs of incorporating reared insects in animal diets as an alternative replacement for expensive conventional protein sources (CPS), mainly fishmeal and soybean meal, remain uncertain due to gradual increase in the sales prices of farmed insects. To date, black soldier fly, yellow mealworm and cricket are the only insect species dominating in the insect farming industry at limited supply. This triggers the need to expand insect farming through the introduction of additional insect species while monitoring the costs of insect-based diets. The commercial rearing of swarming edible insects with a good nutritional profile, such as termites alates (Macrotermes spp.), migratory locusts (Locusta migratoria) and mopane worms (Imbresia belina) found in Southern Africa could potentially become an alternative solution to expand insect farming in addition to the commonly reared insect species. However, there is limited information available on the reproductive ability and economic value of swarming insects as animal feed. Therefore, this paper will provide an overview of the possible rearing of selected swarming insects as well as the profitability of using insect-based diets. It will also give clarity on whether the mass production of edible insects will be cost-effective or not by discussing and comparing recent sales prices of various edible insect as compared to that of CPS in animal diets.