Overview of antimicrobial compounds from African edible insects and their associated microbiota

This review discusses advances in the identification and bioactivity analysis of insect antimicrobial peptides (AMP) compounds, with a focus on small molecules associated with the microbiota of selected African edible insects. These molecules could be used as templates for developing next-generation drugs to combat multidrug-resistant pathogens. Previous research indicates that each insect species produces a distinct antimicrobial peptide that acts against specific microorganisms. The article analyzes several likely AMP-producing insects and their compounds. Edible insect-produced AMPs/small molecules’ chemistry receives little attention as researchers have concentrated on the discovery of antibacterial and antifungal peptides/polypeptides in plants

Can black soldier fly Desmodium intortum larvae-based diets enhance the performance of Cobb500 broiler chickens and smallholder farmers’ profit in Kenya?

This study aimed to evaluate the performance of broiler chickens fed on black soldier fly larvae (BSFL) (Hermetia illucens) and Greenleaf desmodium (Desmodium intortum)-based meals. Study findings show the BSFL-Desmodium mixture could be a valuable replacement for the protein component in conventional feed. Growth performance, carcass quality, and profitability of the poultry were evaluated under various commercial pathways (doorstep, retail, whole, and assorted). The poultry sector is one of the fastest growing industries in Kenya. The highest volume of both poultry, meat, and eggs is produced by local backyard systems characterized by low input and low productivity.Push-Pull for Sub-Saharan Africa Projec

Diversity, host plants and potential distribution of edible Saturniid Caterpillars in Kenya

Saturniids are big colorful caterpillars with spines on their bodies, usually found in shrubs and trees in Sub-Saharan Africa. They are rich in proteins, vitamins, and minerals. The study identifies edible saturniids, diversity, their host plants, their current distribution and to predict possible effects of climate change on their distribution. The paper provides detailed information (including photographs) of seven species of edible saturniids namely Gonimbrasia zambesina, Gonimbrasia krucki, Bunaea alcinoe, Gonimbrasia cocaulti, Gonimbrasia belina, Gynanisa nigra and Cirina forda. Despite being highly nutritious, the diversity of edible saturniid caterpillars has not been studied in Kenya.Federal Ministry for Economic Cooperation and DevelopmentBioInnovate Africa ProgrammeAustralian Centre for International Agricultural Research (ACIAR

In situ nitrogen mineralization and nutrient release by soil amended with black soldier fly frass fertilizer

Black soldier fly frass fertilizer (BSFFF) is effective on crop performance, but information on nitrogen mineralization and nutrient release capacity of soils amended with BSFFF is lacking. This study utilized field incubation experiments to investigate the ammonification, nitrification, microbial populations, and quantities of nutrients released by soils amended with BSFFF and commercial organic fertilizer (SAFI) for a period equivalent to two maize cropping seasons. The paper provides a detailed breakdown and analysis of results. BSFFF has a high potential to supply adequate nutrients for optimal crop production. Higher population of soil bacteria and fungi underline its potential for improving biological soil fertility.Norwegian Agency for Development CooperationNetherlands Organization for Scientific ResearchWOTRO Science for Global Development (NWO-WOTRO)Rockefeller Foundatio

Organic waste substrates induce important shifts in gut microbiota of black soldier fly (Hermetia illucens L.) : coexistence of conserved, variable, and potential pathogenic microbes

The sustainable utilization of black soldier fly (BSF) for recycling organic waste into nutrient-rich biomass such as high-quality protein additive, is gaining momentum. Its gut microbiota is thought to play an important role. The study provides the first comprehensive analysis of bacterial and fungal communities of BSF gut across untreated substrates and highlights conserved members, potential pathogens, and their interactions. Findings show most bacteria found in the BSF gut are transient, and are affected by the local environment. The study contributes to establishment of safety measures for future processing of BSF larval meals and the creation of legislation to regulate their use in animal feeds.Australian Centre for International Agricultural Research (ACIAR)Norwegian Agency for Development CooperationNetherlands Organization for Scientific ResearchWOTRO Science for Global Development (NWO-WOTRO)The Rockefeller Foundatio

Integrating temperature-dependent life table data into Insect Life Cycle Model for predicting the potential distribution of <em>Scapsipedus icipe</em> Hugel &amp; Tanga

Scapsipedus icipe Hugel and Tanga (Orthoptera: Gryllidae) is a newly described edible cricket species. Although, there is substantial interest in mass production of S. icipe for human food and animal feed, no information exists on the impact of temperature on their bionomics. Temperature-dependent development, survival, reproductive and life table parameters of S. icipe was generated and integrated into advanced Insect Life Cycle Modeling software to describe relative S. icipe population increase and spatial spread based on nine constant temperature conditions. We examined model predictions and implications for S. icipe potential distribution in Africa under current and future climate. These regions where entomophagy is widely practiced have distinctly different climates. Our results showed that S. icipe eggs were unable to hatch at 10 and 40°C, while emerged nymphs failed to complete development at 15°C. The developmental time of S. icipe was observed to decrease with increased in temperature. The lowest developmental threshold temperatures estimated using linear regressions was 14.3, 12.67 and 19.12°C and the thermal constants for development were 185.2, 1111.1- and 40.7-degree days (DD) for egg, nymph and pre-adult stages, respectively. The highest total fecundity (3416 individuals/female/generation), intrinsic rate of natural increase (0.075 days), net reproductive rate (1330.8 female/female/generation) and shortest doubling time (9.2 days) was recorded at 30°C. The regions predicted to be suitable by the model suggest that S. icipe is tolerant to a wider range of climatic conditions. Our findings provide for the first-time important information on the impact of temperature on the biology, establishment and spread of S. icipe across the Africa continent. The prospect of edible S. icipe production to become a new sector in food and feed industry is discussed

Organic waste substrates induce important shifts in gut microbiota of black soldier fly (Hermetia illucens L.) : coexistence of conserved, variable, and potential pathogenic microbes

The sustainable utilization of black soldier fly (BSF) for recycling organic waste into nutrient-rich biomass, such as high-quality protein additive, is gaining momentum, and its microbiota is thought to play important roles in these processes. Several studies have characterized the BSF gut microbiota in different substrates and locations; nonetheless, in-depth knowledge on community stability, consistency of member associations, pathogenic associations, and microbe–microbe and host–microbe interactions remains largely elusive. In this study, we characterized the bacterial and fungal communities of BSF larval gut across four untreated substrates (brewers’ spent grain, kitchen food waste, poultry manure, and rabbit manure) using 16S and ITS2 amplicon sequencing. Results demonstrated that substrate impacted larval weight gain from 30 to 100% gain differences among diets and induced an important microbial shift in the gut of BSF larvae: fungal communities were highly substrate dependent with Pichia being the only prevalent genus across 96% of the samples; bacterial communities also varied across diets; nonetheless, we observed six conserved bacterial members in 99.9% of our samples, namely, Dysgonomonas, Morganella, Enterococcus, Pseudomonas, Actinomyces, and Providencia. Among these, Enterococcus was highly correlated with other genera including Morganella and Providencia. Additionally, we showed that diets such as rabbit manure induced a dysbiosis with higher loads of the pathogenic bacteria Campylobacter. Together, this study provides the first comprehensive analysis of bacterial and fungal communities of BSF gut across untreated substrates and highlights conserved members, potential pathogens, and their interactions. This information will contribute to the establishment of safety measures for future processing of BSF larval meals and the creation of legislation to regulate their use in animal feeds.The Canadian International Development Research Centre (IDRC) and the Australian Centre for International Agricultural Research (ACIAR), Norwegian Agency for Development Cooperation, the Section for Research, Innovation, and Higher Education (CAP-Africa), the Netherlands Organization for Scientific Research, WOTRO Science for Global Development (NWO-WOTRO) and The Rockefeller Foundation through the International Centre of Insect Physiology and Ecology (icipe).http://www.frontiersin.org/Microbiologyam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Do organic farming initiatives in Sub-Saharan Africa improve the sustainability of smallholder farmers? Evidence from five case studies in Ghana and Kenya

Organic agriculture (OA) is often regarded as a sustainable agricultural pathway for smallholder farmers in Sub-Saharan Africa, and an increasing number of initiatives promoting OA were initiated over the last decades. However, holistic empirical evidence on the effects of such initiatives on the sustainability of smallholder farmers is still scanty. We analyzed the effects of five initiatives promoting OA on farm-level sustainability. We selected farmers exposed to the initiatives (n = 678) and control farms (n = 957) in five different case studies, two implemented in Ghana and three in Kenya. We used a farm-level multi-criteria assessment tool that evaluates to what extent the environmental, social, economic, and governance sustainability goals formulated in the FAO-SAFA Guidelines are addressed by farmers. We found that the initiatives had limited effects on reducing farmers reliance on chemical inputs use (pesticides and synthetic fertilizers) and uptake of organic or agro-ecological practices. Nevertheless, the results show that the initiatives were able to trigger significant (p-value < 0.05) positive effects mainly for the environmental sustainability goals. In contrast, the goals within the economic, social and good governance sustainability dimensions were rarely affected. Moreover, certified initiatives had more frequently a positive sustainability effect compared to uncertified initiatives

Evolving dynamics of insect frass fertilizer for sustainable nematode management and potato production

Potato production faces major challenges from inadequate soil fertility, and nematode infestation, yet synthetic fertilizers and nematicides are costly and harmful to the environment. This study explored the potential of chitin-fortified black soldier fly-composted organic fertilizer (BSFCOF) as a multipurpose organic fertilizer amendment for enhancing potato yield and suppressing potato cyst nematodes (PCN). The BSFCOF was applied at a rate equivalent to 150 kg N ha-1 and fortified with chitin from black soldier fly pupal exuviae at inclusion rates equivalent to 0.5, 1, 2, 3, 4 and 5% chitin. Data were collected on potato growth characteristics, PCN population densities, and soil chemical properties for two growing cycles. Results showed that chitin fortified BSFCOF significantly improved potato growth parameters, chlorophyll concentration, marketable tuber yield and number of marketable tubers. The marketable tuber yield achieved using chitin-fortified BSFCOF was 70 – 362%, and 69 – 238% higher than the values achieved using unfertilized soil during the first and second growing cycles, respectively. Soil amendment with chitin-fortified BSFCOF significantly reduced the number of cysts per 200 g soil-1, number of eggs and J2 per cyst-1, eggs g-1 soil and reproduction rate by 32 – 87%, 9 – 92%, 31– 98% and 31 – 98%, respectively. The PCN suppression increased with chitin inclusion rates. There were significantly higher values for soil pH, ammonium nitrogen, nitrate nitrogen, available phosphorus, calcium, magnesium, potassium, and cation exchange capacity in soil amended with BSFCOF compared to unamended soil. This study demonstrates that BSFCOF fortified with 5% chitin is an effective soil enhancer with multiple benefits, including improved soil fertility, potato performance, and effective management of potato cyst nematodes

Advances in crop insect modelling methods—Towards a whole system approach

A wide range of insects affect crop production and cause considerable yield losses. Difficulties reside on the development and adaptation of adequate strategies to predict insect pests for their timely management to ensure enhanced agricultural production. Several conceptual modelling frameworks have been proposed, and the choice of an approach depends largely on the objective of the model and the availability of data. This paper presents a summary of decades of advances in insect population dynamics, phenology models, distribution and risk mapping. Existing challenges on the modelling of insects are listed; followed by innovations in the field. New approaches include artificial neural networks, cellular automata (CA) coupled with fuzzy logic (FL), fractal, multi-fractal, percolation, synchronization and individual/agent based approaches. A concept for assessing climate change impacts and providing adaptation options for agricultural pest management independently of the United Nations Intergovernmental Panel on Climate Change (IPCC) emission scenarios is suggested. A framework for estimating losses and optimizing yields within crop production system is proposed and a summary on modelling the economic impact of pests control is presented. The assessment shows that the majority of known insect modelling approaches are not holistic; they only concentrate on a single component of the system, i.e. the pest, rather than the whole crop production system. We suggest system thinking as a possible approach for linking crop, pest, and environmental conditions to provide a more comprehensive assessment of agricultural crop production.Peer reviewe