The global “insect apocalypse,” characterized by a rapid decline in species richness and abundance, poses a significant threat to life on Earth, as insects provide critical ecological services, including their role as food and feed. Consumption of edible insects contributes to the attainment of the sustainable development goal of eradicating hunger, ensuring food security, enhancing nutrition, and advancing sustainable agriculture. Globally, about 2000 edible insect species are consumed by humans but only a few are domesticated. However, a lack of understanding of the rearing regimes of edible insects hinders their domestication. Developing a reliable, cost-effective, and sustainable technology for the mass rearing of edible insect species could alleviate environmental strain caused by the overharvesting and foraging of the species in the wild. The study hypothesizes that transitioning from wild collection to farming can contribute substantially to the sustainability of edible insect consumption in Africa. The study reviewed aspects of the history and importance of edible insect farming. Thereafter, the study provided insight into sustainable methods for mass production of selected edible insects (The African palm larvae, grasshoppers, mopane worm, crickets, and termites), and highlighted the research needs of these insect species. Finally, the study reviewed information on the prospects of edible insect domestication and identified research gaps for future studies.

As key components of terrestrial ecosystems, fungi play vital roles in ecological processes and functions, and are associated with innumerable plant, vertebrate, and arthropod taxa. Among arthropod taxa, aphids (Hemiptera) are commonly found in both natural and agricultural ecosystems, where some species cause substantial crop damage. Here, we provide a novel and unique dataset, AphidFunga, compiling associations between fungi and aphids extracted from 412 scientific publications, spanning 167 years and covering 85 countries. Fungal and aphid taxonomies were revised to recent nomenclature, whereas association types were updated based on current knowledge. The AphidFunga database currently contains 2993 aphid-fungal association records, linking 365 aphid host taxa (species or genera) with 149 fungal taxa, 95% of which are entomopathogenic. The database is available in three formats: a combined comma-separated data table, a set of R data frames, and a MySQL relational database. The AphidFunga database lays the foundation for further research on fungus-mediated ecosystem processes and functions, and supports conservation science, policy development, and applications in crop protection and environmental management.

The traditional methods of sourcing and semi-domesticating the African palm weevil Rhynchophorus phoenicis Fabricius (Coleoptera: Curculionidae) larvae persist among the inhabitants of Ghana. However, these methods produce only a small proportion of the market demand for the larvae in Ghana. A containerized system of producing larvae has been found to facilitate production for socioeconomic purposes, thereby enhancing the sustainable utilization of the larvae all year round. We evaluated the life history parameters of R. phoenicis on three different rearing protocols that used different agricultural by-products, container types, and number of adult pairs for production. The different protocols were laid out using the Completely Randomized Design (CRD) with 10 replications. The fecundity of the adults differed significantly among the protocols. The highest fecundity was recorded on Protocol 2 (145.50 +/- 16.55), followed by control (98.50 +/- 12.05), Protocol 3 (84.50 +/- 9.50), and Protocol 1 (45.00 +/- 11.58). Protocol 2 recorded the highest larval survival rate, followed by Protocols 1, control, and 3. Among the rearing protocols, the highest intrinsic rate of natural increase (rm) (days) and net reproductive rate (Ro) were observed in Protocol 2. The lowest mean generational time (T) was recorded on Protocol 2 (76 days) while the highest (92 days) was recorded on Protocol 3. Our findings showed that Protocol 2 supports fecundity, larval development, cocooning formation, and adult emergence. The adoption of Protocol 2 by smallholder insect farmers can contribute to the development of future commercial rearing systems for R. phoenicis larvae.

The edible grasshopper, Ruspolia diJferens (Orthoptera: Tettigoniidae) is food and a source of income for many people in East Africa. Recent laboratory experiments have succeeded in rearing them on germinated finger millet (GFM). However, long-term mass production on such a feed would be costly. Incorporating inexpensive and locally abundant agricultural byproducts into GFM could be another option to lower the production cost while maximising its profits. We experimentally evaluated the effect of blending GFM with 25%, 50%, or 75% by weights of three agricultural byproducts (soybean hull meal, local brew waste and dry maize cob) on the survival, developmental period, adult wet weight and reproductive performance of R. diJferens. A total of 390 R. diJferens were reared individually on each of the dietary treatments, including GFM as control, till death. Data was analysed using generalised linear models. Overall, the R. diJferens performed optimally on GFM supplemented with dry maize cob, and poorly on GFM supplemented with soybean hull meal. However, performance varied across supplementation levels with dry maize cob. GFM supplemented with 25% dry maize cob yielded the highest overall survival (86.2%) and highest 14-day-old male adult wet weight (0.54 g). While the shortest overall developmental period (86.8 days), highest fledgling adult wet weight (0.53 g), and highest 14-day-old female adult wet weight (0.82 g) were observed on GFM supplemented with 50% dry maize cob. Supplementing GFM with 75% dry maize cob resulted in the shortest pre-oviposition period (10.6 days) and the highest percentage hatchability (82.7%). Generally, supplementing GFM with dry maize cob greatly improves the performance of R. diJferens. Our findings recommend including dry maize cob on the list of low-cost substrates for the farming of this endangered valuable edible insect species.

The insect-pathogenic fungal genus Strongwellsea (Entomophthorales) contains specialist species infecting only adult cyclorrhaphan flies with an infection that will usually develop one, two or even three abdominal holes through which conidia are discharged while the fly is still alive. We describe three new species from Strongwellsea infecting adult flies from the family Anthomyiidae. Strongwellsea caulis infects cabbage root fly, Delia radicum, Strongwellsea lata infects Anthomyia liturata, and Strongwellsea potentia infects Hylemya vagans. The descriptions of the three new species are based on 1) pathobiology as revealed by their differing natural host species, 2) the morphologies of primary conidia and resting spores, and 3) their differing by ITS2 sequences. Of particular importance is that the two pest species cabbage fly D. radicum and bean seed fly Delia platura are infected by different species from Strongwellsea, namely S. caulis and Strongwellsea castrans respectively. Our findings suggest the existence of a high but still poorly known diversity of highly specialized Strongwellsea species infecting adult flies from Anthomyiidae that necessitated our emendation of S. castrans to clarify the differences among the species in the complex of anthomyiid pathogens.

Studies on community composition and population structure of entomopathogenic fungi are imperative to link ecosystem functions to conservation biological control. We studied the diversity and abundance of Metarhizium spp. from soil of conventionally and organically farmed strawberry crops and from the adjacent field margins in two different climatic zones: Brazil (tropical) and Denmark (temperate), using the same isolating methods. In Brazilian strawberry soil, Metarhizium robertsii (n = 129 isolates) was the most abundant species, followed by M. humberi (n = 16); M. anisopliae (n = 6); one new taxonomically unassigned lineage Metarhizium sp. indet. 5 (n = 4); M. pingshaense (n = 1) and M. brunneum (n = 1). In Denmark, species composition was very different, with M. brunneum (n = 33) being isolated most commonly, followed by M. flavoviride (n = 6) and M. pemphigi (n = 5), described for the first time in Denmark. In total, 17 haplotypes were determined based on MzFG543igs sequences, four representing Danish isolates and 13 representing Brazilian isolates. No overall difference between the two climatic regimes was detected regarding the abundance of Metarhizium spp. in the soil in strawberry fields and the field margins. However, we found a higher Shannon's diversity index in organically managed soils, confirming a more diverse Metarhizium community than in soils of conventionally managed agroecosystems in both countries. These findings contribute to the knowledge of the indigenous diversity of Metarhizium in agricultural field margins with the potential to contribute to pest regulation in strawberry cropping systems.

The fungal order Entomophthorales in the Zoopagomycota includes many fungal pathogens of arthropods. This review explores six genera in the subfamily Erynioideae within the family Entomophthoraceae, namely, Erynia, Furia, Orthomyces, Pandora, Strongwellsea, and Zoophthora. This is the largest subfamily in the Entomophthorales, including 126 described species. The species diversity, global distribution, and host range of this subfamily are summarized. Relatively few taxa are geographically widespread, and few have broad host ranges, which contrasts with many species with single reports from one location and one host species. The insect orders infected by the greatest numbers of species are the Diptera and Hemiptera. Across the subfamily, relatively few species have been cultivated in vitro, and those that have require more specialized media than many other fungi. Given their potential to attack arthropods and their position in the fungal evolutionary tree, we discuss which species might be adopted for biological control purposes or biotechnological innovations. Current challenges in the implementation of these species in biotechnology include the limited ability or difficulty in culturing many in vitro, a correlated paucity of genomic resources, and considerations regarding the host ranges of different species.

Entomophthoralean fungi have long been recognized as promising candidates for biological insect pest control. However, due to technical challenges, no preparation based on these fungi has been established for practical use so far. Low water availability is a key limiting factor of conidial discharge and germination. In the present study, sporulation of psyllid-pathogenic entomophthoralean fungus Pandora cacopsyllae Eilenberg, Keller and Humber (Entomophthorales Entomophthoraceae) was not observable under reduced water activity (a W ≤ 0.97). To support sporulation of encapsulated P. cacopsyllae hyphae from submerged culture under low humidity conditions in above-ground applications in field, we developed a novel paste-type formulation containing biobased superabsorbents, which retained water for a prolonged time period. In co-application with the superabsorbent formulation, the otherwise fast-drying capsules were kept sufficiently moist for sporulation for at least six days in laboratory trials at low humidity below 40%. Using the new formulation, we measured conidial discharge by P. cacopsyllae from the capsules under dry semi-field conditions in summertime by trapping conidia at a vertical distance of up to 40 cm from the sporulation source. By considering the cardinal directions, fewer conidia were discharged on the sun-facing side in the east than on the sun-averted side in the west. The developed formulation improved the sporulation efficacy significantly. Since water availability is a limiting factor for many fungal biocontrol agents, the developed formulation has the potential to also improve their efficacy.

Metarhizium rileyi is an entomopathogenic fungus with a narrow host range which distinguishes it from other Metarhizium species with broad host ranges. This species is also unique because the initial yeast-like growth on solid media is only observed in liquid culture in other Metharizium species. A lack of knowledge about the metabolism and genetic signatures of M. rileyi during this yeast-like phase on solid and in liquid media is a bottleneck for its large-scale production as a commercial biocontrol agent. In this study we found that M. rileyi yeast-like cells produced on solid medium infected and killed the important insect pest Spodoptera frugiperda with comparable efficiency as yeast-like cells grown in liquid medium. Secondly, we used comparative transcriptomic analysis to investigate the active genes and genomic signatures of the M. rileyi yeast-like morphotypes produced on solid and in liquid media. Yeast-like cells grown in liquid medium had upregulated genes relating specifically to signal transduction and particular membrane transporters. Thirdly, we compared the transcriptomic profiles of yeast-like phases of M. rileyi with those of M. anisopliae. The yeast-like phase of M. rileyi grown on solid medium upregulated unique genes not found in other Metarhizium species including specific membrane proteins and several virulence factors. Orthologous genes associated with heat shock protein, iron permease, membrane proteins and key virulence traits (e.g. collagen-like protein Mcl1) were upregulated in both species. Comparative transcriptome analyses of gene expression showed more differences than similarities between M. anisopliae and M. rileyi yeast-like cells.

The new species Pandora cacopsyllae Eilenberg, Keller & Humber (Entomophthorales) is described. The fungus was found on infected pear psyllids Cacopsylla pyri (Hemiptera: Psyllidae) in a pear orchard in Zealand, Denmark. Morphological structures (conidia, rhizoids, cystidia) were described on the designated type host C. pyri. In addition, conidia from an in vitro culture were described. Pandora cacopsyllae differs from other Pandora species by a) C. pyri is the natural host; b) conidia are different from other Pandora species infecting Psylloidea; c) ITS differs from other Pandora species infecting Hemiptera. The fungus has a high potential for future use in biological control of Cacopsylla pest species as well as other psyllids.

The African palm weevil Rhynchophorus phoenicis (Fabricius) is an alternative to conventional protein sources from livestock and poultry due to their rich nutritional content and ability to be reared on agricultural by-products. When establishing a production protocol for mass production of R. phoenicis larvae, it is imperative to understand the interaction between substrate and temperature on the development and reproductive success of the weevils. To determine the optimum temperatures for continuous production of R. phoenicis, the larvae were subjected to four temperatures (20 degrees C, 25 degrees C, 30 degrees C, and 35 degrees C) at a relative humidity of 70% on different substrates (elephant ear corm, peeled sugarcane, and palm yolk) in an incubator. The developmental duration of R. phoenicis larvae decreased with a temperature above 30 degrees C whilst percentage larval survival was high at 20 degrees C and 25 degrees C. The temperature with the fastest larval development and highest mortality was 35 degrees C. The optimal temperature from egg to the adult stage was observed at 25 degrees C. The oviposition and hatchability of eggs was high on elephant ear corm (EC), and palm yolk (PY) at 25 degrees C whilst the number of cocoons was high at 20 degrees C on decorticated coconut coir (DC). Thus, it is feasible to utilise the easily accessible substrates that interact well with temperature to produce optimum condition for the production of R. phoenicis larvae.

Pandora sp. nov. inedit. (ARSEF13372) is a recently isolated entomophthoralean fungus with high potential for psyllid pest control. The use of entomopathogenic fungi as biocontrol agents in large-scale field application requires biomass production in a sufficient quantity and quality. This work is the first attempt to explore the biomass production of the novel entomophthoralean Pandora species in a liquid medium. This study aims at establishing a submerged fermentation process with potential for mass production of the fungus. Three different complex nutrient sources were evaluated for maximising biomass in a liquid shaking culture. Pandora sp. nov. grew best in media containing skimmed milk, but even faster in a mixture of skimmed milk, yeast extract and a low-cost protein hydrolysate from animal by-products. Subsequently, the produced biomass can be encapsulated in biopolymer beads or granules in order to transfer the fungus into an easily applicable form. Therefore, growth as finely dispersed mycelium was promoted by increased media osmolality through the addition of sodium chloride. After the medium had been transferred to a stirred tank bioreactor with a working volume of 8 L, a maximum biomass dry weight of 21 g center dot L-1 was reached after 48 h. These promising results can pave the way for large-scale fermentation and formulation processes of this novel Pandora species for biological psyllid pest control.

Ruspolia differens (Serville) (Orthoptera: Tettigoniidae), also known as the ‘edible grasshopper’, ‘African edible bush-cricket’, and ‘nsenene’, is regarded as one of the most promising edible insect species that can be used for food, particularly in Sub-Saharan Africa. However, there is insufficient information on suitable diets and their effects on survival, adult weight, fecundity, and developmental time of this species, which are preconditions for large-scale production. In this study, we experimentally evaluated the effects of 12 diets (wheat bran, rice seed head, finger millet seed head, soya bran, maize bran, fresh maize comb, millet flour, chicken feed egg booster, simsim cake, sorghum seed head, powdered groundnut, and germinated finger millet), that are known to be accepted by R. differens, on their growth and reproductive parameters. The survival rate, developmental time, and adult weight varied considerably on the various diets. The highest nymphal survival rates, shortest development times, and highest adult weights were recorded for both sexes when fed fresh maize comb and germinated finger millet diet. Lifetime fecundity of females fed on germinated finger millet also was, on average, more than twice higher compared to other diets. The present study demonstrated that relatively inexpensive and locally available germinated finger millet, fresh maize seed (at the silking stage on the comb), sorghum seedhead, and finger millet seedhead could be successfully used to rear and sustain populations of R. differens. Our findings contribute to the future design of an effective mass-rearing system for this economically important edible insect.

Insect breeding or farming for food and feed is an emerging enterprise that can address the ever-growing demand for protein and curb high unemployment rates in Africa and beyond. However, for the sector to prosper, its value chain needs to be regulated to ensure sustainability and safety for consumers and the environment. Although a few African countries, such as Kenya, Uganda and Rwanda, have promulgated standards on the use of insects as food and feed, greater efforts are needed in other countries, and relevant policies governing the sector need to be formulated. All over the globe, attention to the regulation of the edible insect sector is increasing, and more investment in the industry is foreseen. Safety issues such as identifying which species should be reared, substrate quality and traceability imposed by importing countries will be critical for expansion of the sector. This paper analyses safety, regulatory and environmental issues related to breeding and international trade of edible insects in Africa and provides case studies and recommendations for sustainable use of insects for food and feed.

Two new species from the genus Strongwellsea (Entomophthorales: Entomophthoraceae) that infect adult flies from the genus Helina (Muscidae) are described: Strongwellsea selandia Eilenberg & Humber infecting adult Helina evecta (Harris), and Strongwellsea gefion Eilenberg & Humber infecting adult Helina reversio (Harris). The descriptions are based on pathobiological, phenotypical and genotypical characters. The new species differ from other described members from the genus Strongwellsea by a) pathobiology as revealed by natural host species, b) morphology of primary conidia, c) color of resting spores, and d) genotypical clustering based on analysis of ITS2. The two new species have only been documented from North Zealand, Denmark

Optimising the production of insects for food and feed and ensuring their health are growing concerns for producers. Insects suffer from a range of insect pathogenic microorganisms, and the management of such diseases is essential. One solution is the introduction of beneficial probiotic bacteria into the diet of the insects. Here, we show that a lactic acid bacterial strain, Pediococcus pentosaceus, isolated from the gut of the mealworm, Tenebrio molitor, was able to inhibit the growth of selected insect pathogens in vitro. Using in vivo assessments of the host's fitness benefits conferred by the lactic bacterium we show a significant effect of P. pentosaceus on larval growth rate and survival into adulthood. Gut microbiota analysis focusing on bacterial composition based on 16S rRNA gene amplicon sequencing suggests that P. pentosaceus could have successfully colonised the guts, or altered their bacteria, of the larvae that received it. Finally, we discuss our results in the context of mass insect production systems and outline the remaining work needed to explore and secure the role of beneficial bacterial additives in the field.

Rearing of the black soldier fly, Hermetia illucens , in mass production systems is increasing. Its use as both a bio-converter of organic waste and as feed for other livestock has transformed it into one of the most produced insects in the world. As a result, new research is needed to evaluate the risk of insect diseases affecting it and thus productivity. While some studies have focused on the larval stage of the flies, to date, few have assessed risks to the adult stage, vital to the production system. In this study, the susceptibility of adult black soldier flies to the entomopathogenic fungus, Beauveria bassiana KVL 03-122 was evaluated in laboratory experiments by quantifying mortality, egg-laying capacity, and sporulation when the flies were subjected to two concentrations of the fungus. The findings showed that adult flies are susceptible to the biocontrol agent B. bassiana , with high mortality and low egg count in the high dose treatment. Our results confirmed that adult black soldier flies appear susceptible to a fungal pathogen and we discussed the findings in relation to consequences for production.

A new species from the genus Strongwellsea (Entomophthorales: Entomophthoraceae) is described: Strongwellsea crypta Eilenberg & Humber from adult Botanophila fugax (Meigen) (Diptera: Anthomyiidae). The description is based on pathobiological, phenotypical and genotypical characters. The abdominal holes in infected hosts develop rapidly and become strikingly large and edgy, almost rhomboid in shape. The new species S. crypta differs from S. castrans, the only described species infecting flies from Anthomyiidae, by: (a) naturally infecting another host species, (b) by having significantly longer primary conidia, and (c) by genotypical clustering separately from that species when sequencing ITS2.

Due to a swift and continuous growth of the insect rearing industry during the last two decades, there is a need for a better understanding of insect diseases (caused by insect pathogens). In the insect production sector, insect diseases are a bottleneck for every type and scale of rearing system with different degrees of technology investment (i.e. semi-open rearing, closed rearing, industrial production, small-scale farming). In this paper, we provide an overview of insect pathogens that are causing disease in the most common insect species reared or collected for use in food and feed. We also include a few examples of diseases of insect species, which are not (yet) reported to be used as food or feed; those examples may increase our understanding of insect diseases in general and for the development of disease prevention and control measures. We pay special attention to the effect of selected biotic and abiotic factors as potential triggers of insect diseases. We discuss the effect of such factors in combination with other production variables on disease development and insect immunocompetence. Additionally, we touch upon prevention and control measures that have been carried out and suggested up to now for insect production systems. Finally, we point towards possible future research directions with possibilities to enhance the resilience of insect production to insect disease outbreaks.

A new but still unpublished entomopathogenic fungus (ARSEF13372) in the genus Pandora (Entomophthorales: Entomophthoraceae) was originally isolated from Cacopsylla sp. (Hemiptera: Psyllidae). Several species of the genus Cacopsylla vector phloem-borne bacteria of the genus 'Candidatus Phytoplasma', which cause diseases in fruit crops such as apple proliferation, pear decline and European stone fruit yellows. To determine Pandora's host range and biocontrol potential we conducted laboratory infection bioassays; Hemipteran phloem-feeding insects were exposed to conidia actively discharged from in vitro produced mycelial mats of standardized area. We documented the pathogenicity of Pandora sp. nov. to species of the insect families Psyllidae and Triozidae, namely Cacopsyllapyri L., C.pyricola (Foerster), C.picta (Foerster, 1848), C.pruni (Scopoli), C.peregrina (Foerster), and Trioza apicalis Foerster. The occurrence of postmortem signs of infection on cadavers within 10 days post inoculation proved that Pandora sp. nov. was infective to the tested insect species under laboratory conditions and significantly reduced mean survival time for C.pyri (summer form and nymph), C.pyricola, C.picta, C.pruni, C.peregrina and T.apicalis. Assessing a potential interaction between phytoplasma, fungus and insect host revealed that phytoplasma infection ('Candidatus Phytoplasma mali') of the vector C.picta and/or its host plant apple Malus domestica Borkh. did not significantly impact the survival of C.picta after Pandora sp. nov. infection. The results from infection bioassays were discussed in relation to Pandora sp. nov. host range and its suitability as biocontrol agent in integrated pest management strategies of psyllid pests, including vector species, in orchards.