This paper reviews entomophagy as practised in Africa within the context of food and nutritional security by providing an inventory of the various species of insects that are consumed on the continent and suggests a research for development (R4D) agenda for sustainable utilisation of insects for food and feed. Our survey showed that over 470 species of insects are eaten in Africa. The Central African region remains the most important hotspot of having a culture of entomophagy. The insects mostly eaten in the continent are dominated by the orders Lepidoptera, Orthoptera and Coleoptera. Commonalities were observed across the majority of the insects consumed across Africa, providing opportunities for related R4D activities. An R4D agenda and pathways for using edible insects suggest that socio-economics and marketing studies should address issues of communities' perceptions, based on their cultural background, income and beliefs. Cost-effective rearing, harvesting and processing technologies are required to prevent depletion and ecological perturbations while ensuring continuous availability of insect-based products. Indigenous reports assert that some edible insects harbour medicinal properties; thus, the need to undertake nutritional and bioactive chemical characterisation of main edible insects along the value chain and to investigate food safety issues such as diseases, allergies, and toxicological and chemical hazards. The use of insects for waste conversion into animal feed and fertiliser requires judicious choice of substrate in view of concerns regarding contaminant loads and pathogens occurrence. Responding to these research needs and opportunities, icipe has recently established an Insects for Food, Feed and Other Uses Programme with well-defined work packages oriented towards attainment of its Vision and Strategy 2013-2020 document, with a strong orientation towards R4D and a focus on activities that lead to adoption and impact on end users, through broad based complementary linkages and partnerships with agriculture and livestock extension services, Food and Agriculture Organization of the United Nations, Consultative Group on International Agricultural Research and advanced research institutes, non-governmental organisations and the private sector.

No abstract

In Africa, livestock production currently accounts for about 30% of the gross value of agricultural production. However, production is struggling to keep up with the demands of expanding human populations, the rise in urbanization and the associated shifts in diet habits. High costs of feed prevent the livestock sector from thriving and to meet the rising demand. Insects have been identified as potential alternatives to the conventionally used protein sources in livestock feed due to their rich nutrients content and the fact that they can be reared on organic side streams. Substrates derived from organic by-products are suitable for industrial large-scale production of insect meal. Thus, a holistic comparison of the nutritive value of Black Soldier Fly larvae (BSFL) reared on three different organic substrates, i.e. chicken manure (CM), brewers’ spent grain (SG) and kitchen waste (KW), was conducted. BSFL samples reared on every substrate were collected for chemical analysis after the feeding process. Five-hundred (500) neonatal BSFL were placed in 23 × 15 cm metallic trays on the respective substrates for a period of 3–4 weeks at 28 ± 2 °C and 65 ± 5% relative humidity. The larvae were harvested when the prepupal stage was reached using a 5 mm mesh size sieve. A sample of 200 grams prepupae was taken from each replicate and pooled for every substrate and then frozen at −20 °C for chemical analysis. Samples of BSFL and substrates were analyzed for dry matter (DM), crude protein (CP), ether extracts (EE), ash, acid detergent fibre (ADF), neutral detergent fibre (NDF), amino acids (AA), fatty acids (FA), vitamins, flavonoids, minerals and aflatoxins. The data were then subjected to analysis of variance (ANOVA) using general linear model procedure. BSFL differed in terms of nutrient composition depending on the organic substrates they were reared on. CP, EE, minerals, amino acids, ADF and NDF but not vitamins were affected by the different rearing substrates. BSFL fed on different substrates exhibited different accumulation patterns of minerals, with CM resulting in the largest turnover of minerals. Low concentrations of heavy metals (cadmium and lead) were detected in the BSFL, but no traces of aflatoxins were found. In conclusion, it is possible to take advantage of the readily available organic waste streams in Kenya to produce nutrient-rich BSFL-derived feed.

The ever-increasing animal feed costs are driving many vulnerable communities involved in animal husbandry out of business. The high cost is mainly driven by the protein source, which represents the most expensive component in animal feed. In conventional feed, protein is obtained mainly from soybean and fish meal (SFM). The present study explored potential of partially replacing this SFM with black soldier fly prepupae meal (BSFPM) in Cobb 500 broiler chicken diets. A SFM-based diet was compared to three experimental diets formulated by partially substituting SFM with BSFPM at 13.8, 27.4, and 42.0% of the crude protein (CP) in the starter feed and 11.0, 37.2, and 55.5% of the CP in the finisher feed of diets D1, D2, and D3, respectively. Dietary effects on average daily feed intake, average daily body weight gain, feed conversion ratio, carcass characteristics, breast meat sensory attributes, and the economic implication of their use in broiler production were evaluated. Replacement of SFM with BSFPM did not affect daily feed intake, daily body weight gain, feed conversion ratio, aroma or taste of cooked breast meat. A 16.0% higher Cost Benefit Ratio and 25.0% better Return on Investment was recorded when the birds were reared on the highest concentration of black soldier fly (D3) compared to the conventional diet which was 19.0% more expensive. The implication of these findings for the promotion of insect mass production enterprises for animal feed protein, and their potential for income generation and job creation particularly in developing countries is discussed.

Efforts to recycle organic wastes using black soldier fly (BSF) Hermetia illucens into high-nutrient biomass that constitutes a sustainable fat (biodiesel) and high-quality protein ingredient in animal feeds have recently gained momentum worldwide. However, there is little information on the most suitable rearing conditions for growth, development and survivorship of these flies, which is a prerequisite for mass production technologies. We evaluated the physiological requirements for growth and reproduction of H. illucens on two diets [spent grains supplemented with brewers’ yeast (D1) and un-supplemented (D2)]. Development rates at nine constant temperatures (10–42°C) were fitted to temperature-dependent linear and non-linear day-degree models. Thereafter, life history table parameters were determined within a range of favourable temperatures. The thermal maximum (TM) estimates for larval, pre-pupal and pupal development using non-linear model ranged between 37.2 ± 0.3 and 44.0 ± 2.3°C. The non-linear and linear day-degree model estimations of lower developmental temperature threshold for larvae were 11.7 ± 0.9 and 12.3 ± 1.4°C for D1, and 10.4 ± 1.7 and 11.7 ± 3.0°C for D2, respectively. The estimated thermal constant of immature life stages development of BSF was higher for the larval stage (250±25 DD for D1 and 333±51 for D2) than the other stages evaluated. Final larval wet weight was higher on D1 compared to D2. The population growth rate was most favourable at 30-degree celsius (°C) with higher intrinsic rate of natural increase (rm = 0.127 for D1 and 0.122 for D2) and shorter doubling time (5.5 days for D1 and 5.7 days for D2) compared to the other temperatures. These results are valuable for the optimization of commercial mass rearing procedures of BSF under various environmental conditions and prediction of population dynamics patterns using computer simulation models.

No abstract

In many African cultures, insects are part of the diet of humans and domesticated animals. Compared to conventional food and feed sources, insects have been associated with a low ecological foot print because fewer natural resources are required for their production. To this end, the Food and Agriculture Organization of the United Nations recognized the role that edible insects can play in improving global food and nutrition security; processing technologies, as well as packaging and storage techniques that improve shelf-life were identified as being crucial. However, knowledge of these aspects in light of nutritional value, safety, and functionality is fragmentary and needs to be consolidated. This review attempts to contribute to this effort by evaluating the available evidence on postharvest processes for edible insects in Africa, with the aim of identifying areas that need research impetus. It further draws attention to potential postharvest technology options for overcoming hurdles associated with utilization of insects for food and feed. A greater research thrust is needed in processing and this can build on traditional knowledge. The focus should be to establish optimal techniques that improve presentation, quality and safety of products, and open possibilities to diversify use of edible insects for other benefits.

No abstract