Development of sustainable mass-rearing of locusts for food and feed in South Africa

Abstract

Abstract Like any other edible insects, locusts are an alternative source of protein that could supplement livestock and human foods. This study selected indigenous locust species with a high reproductive and rapid growth rate to determine the most favourable feeding plant species for locust mass-rearing. A suite of seven locust species, Acanthacris ruficornis (Fabricius, 1787), Cantantops melanostictus (Schaum, 1870) Locusta migratoria (Linnaeus, 1758), Petamella prosternalis (Karny, 1907), Chortoicetes terminifera (Walker, 1870), Cataloipus zulvensis (Sjöstedt, 1929) and Ornithacris cyanea (Uvarov, 1924) (Orthoptera: Acrididae) were collected from tribal orchards in Lufule, Tshikweta and Belleview villages in Limpopo province, South Africa and reared on the crop feeding plant species. The feeding, reproductive output (nymph production), adult longevity, and mortality of the suite of the locust species were determined on Zea mays L. (Poaceae), Phaseolus vulgaris L. (Fabaceae) and Panicum maximum jacq. (Poaceae) under the control, choice-one, choice-two, and choice-three tests. Choice-one and -two tests had three and two feeding plants, respectively. Whilst both the control and choice-three tests had a single-feeding plant species. I found that locust feeding, reproductive output, adult longevity, and mortality depended on the plant species, and this was more significant for the control, and choice-one compared to the choice-two and choice-three tests. Both the nymphs and adults of the locusts fed significantly more on P. vulgaris and Z. mays, respectively. Locust colonies exposed to P. maximum in the choice-three test reproduced and survived lesser significantly than all the tests. Results suggest that the combination of P. vulgaris and Z. mays or P. vulgaris alone can be used to mass-rear the suite of the locust species, particularly C. melanostictus, A. ruficornis and C. terminifera. Presented here are the most sustainable locust-rearing methods using crop plant species with rapid propagation responses. These results could be implemented as either extensive-or small-scale rearing for research or commercial purposes in South Africa and elsewhere.