Diversity of edible insects and their related indigenous knowledge: evidence from KwaZulu-Natal and Limpopo provinces, South Africa.

Abstract

Entomophagy is an ancient indigenous practice that has played a significant role in human nutrition around the world. In addition, the traditional use of edible insects forms an important part of food culture in Africa. Edible insects are widely consumed across the African continent for their taste, nutritional value, or as an emergency food source during times of food shortage. They have been proposed and recommended as a sustainable food source that can assure food security, because edible insects are rich in protein, fats, amino acids, iron, zinc, and energy. As a result, edible insects play an essential role in human nutrition. In addition, the trade of edible insects plays an important role in improving livelihoods in developing countries. However, little is known about the diversity and nutritional composition of various insects consumed in South Africa. In addition, little is being done to document traditional knowledge on the consumption of insects, and processes involved in harvesting, processing, and preparing edible insects. This study aimed to document indigenous knowledge regarding the consumption of edible insects, their diversity and distribution, and their nutritional composition. This was done by (i) reviewing existing literature on the diversity of insect and their nutritional status in Africa. (ii) documenting consumption patterns, methods, or techniques used in collecting and preparing insects in South Africa. (iii) determining the nutritional composition of some major insect groups consumed in Africa, (iv) determining the most preferred insect groups, and (v) by documenting the socio-economic benefits of trading insects. Closed and open-ended questions were conducted in various rural areas in five and four local municipalities in KwaZulu-Natal (KZN) and Limpopo. To document indigenous knowledge about trading, consumption, collection and preparation methods used in these provinces. Dried samples of four insect groups were procured from different markets across Vhembe district, Limpopo Province. The nutritional composition of the procured insect types was analysed using the standard Association of Official Analytical Chemist (AOAC) methods. A systematic review was conducted to determine the diversity and nutritional composition of edible insects consumed in Africa. A systematic review search resulted in 98 eligible papers listing 212 edible insect species from eight orders that are used as food in Africa. The highest protein (range: 20–80%) and fat (range: 10–50%) content were recorded in order Lepidoptera. While the highest carbohydrates (range: 7–54%) content was reported in order Coleoptera. Majority of the people still practice entomophagy in Limpopo while, there are only a few people consuming insects in KwaZulu-Natal. Gynanisa caterpillar, Gonimbrasia belina (mopane worm), termites, Encosternum delegorguei (stink bug), Cirina forda (emperor moth), Locustana spp. (brown locust), Zenocerous spp. (grasshopper), Carebara vidua (ant), and Cicadoidea spp. (cicada) were used as food in Limpopo and KwaZulu-Natal. From these, mopane worms and termites were the most preferred species. These insects were primarily collected from the wild, and consumed either fried, boiled, roasted, sundried, or as relish. Nutritional benefits and tradition were the primary reason for consuming insects in the two provinces. However, religion and discomfort associated with consuming insects were the main reasons for not consuming insects. Findings from the nutritional analysis of four insect types showed that termite (soldiers/ workers) had the highest protein and iron content, while Gynanisa caterpillar had the highest zinc content. The ranges of the percentage contribution of the insects studied relative to the Estimated Average Requirement (EAR) for protein amongst different age groups, indicated that the insects would contribute significantly to addressing protein deficiencies, 89.5-160.4% EAR for 4-8 years old children and 29.9-53.6% EAR for childbearing women (19-50 years). However, because Gonimbrasia belina are consumed in a relatively higher portion size than the other edible insects, it would be a good source of protein for different population groups. Generally, boiling with or without salt added resulted in a significant increase in protein, iron, and zinc content of Gonimbrasia belina samples. On the other hand, frying resulted in a significant decrease in protein content of Gonimbrasia belina samples. Five insect groups were traded for cash income in Vhembe district, Limpopo province. Of these, mopane worm was the most traded insect. Trading insects provided financial support and cash income to unemployed people in this province. Income generated from trading insects range from R100 - R200 ($6, 2 - $12, 3) per week to above R2000 ($123, 3) per week with the majority of traders making an income of R600 -R1000 ($36, 9-$61, 6) per week. Unemployment and poverty were the main reason for trading insects. Despite the economic benefit associated with trading insects, few governmental organizations in Limpopo included edible insects in economic development strategies. In addition, insect trading took place in the informal markets along the street, pavements, and on table stalls made of cardboard and wood. Safety and hygiene were the major issues of concern stated by the respondents in Vhembe district. Therefore, government need to provide infrastructure and financial support to improve the trading conditions of edible insects. Also, policy and legislation that recognise and govern the consumption, trading, and harvesting of edible insects are required, because edible insects play an important role in income generation. In addition, edible insects contribute to food and nutrition security in developing countries with chronic nutrient deficiencies. Therefore, the consumption of insects should be promoted and encouraged in poor communities.