Habitats and nutritional composition of selected edible insects in Zimbabwe

Edible insects are gaining recognition as food with potential of contributing to attainment of household food security. In sub-Saharan Africa, sustainable use of insects as food is threatened by lack of data on host plants and habitat associations. In addition, lack of nutritional data on most edible insects reduces consumer confidence and limits integration of insect consumption with other food sources. This study was undertaken to review, collate and assemble dispersed information of some edible insects of Zimbabwe. Data on species identities, host plants and habitats were gathered for 14 species from reputable literature sources and Bulawayo Natural History Museum records. In addition, nutritional assessments were carried out on 10 widely consumed insects in Zimbabwe. Standard ecological sampling procedures were used to collect insect specimens. Proximate analyses were conducted following the Association of Official Analytical Chemists standard procedures using dried pulverised material. Majority (60%) of reviewed insects had reliable host plants and habitats records. More than half of these were recorded in agro-ecosystems. On dry matter basis, protein content ranged from 22% (Gryllotalpa africana) to 55.4% (Gonimbrasia belina); fat content ranged from 10.8% (G. africana) to 41.6% (Macrotermes natalensis). Ash content was > 10% in the ground dwelling G. africana (12.6%) and Eulopida mashona larvae (10.9%). Wide species differences were recorded for carbohydrate content; 0.4% in M. natalensis and 47.2% in G. africana. Carbohydrates content was inversely related to protein and fat contents for all insects. Energy and fat contents were positively related in all the insects. Overall, insect species from this study have high proximate constituents that can match plant and animal products diets and can be considered as potential viable alternative nutritious food sources. Findings from this study are expected to promote greater recognition of insects as food in Zimbabwe and encourage up-scaling of their sustainable utilisation.