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Two fly species, the black soldier fly, Hermetia illucens, and the house fly, Musca domestica, are presently being promoted and used as feed for monogastric animals. Various production systems are being developed in different contexts and regions, from very small-scale used by smallholder farmers to industrial scale production factories. This chapter reviews the information available on production methods for the two fly species, with a focus on small-scale production systems. Larvae of both fly species can be produced either by exposing substrates to attract naturally occurring flies, or by breeding adults to obtain eggs that will be placed on the larval rearing substrates. The two fly species are compared with respect to performance, user-friendliness, safety and sustainability. The advantages and disadvantages associated with rearing these species in different situations and perspectives are highlighted. This chapter also discusses knowledge gaps and provides recommendations for production and suggestions for further research.

Opportunistic bacteria are often ubiquitous and do not trigger disease in insects unless the conditions are specifically favorable for bacterial development in a suitable host. In this paper, we isolated and identified a bacterium, Pseudomonas aeruginosa, from the larvae of the giant mealworm Zophobas morio and we studied the possible entry routes by challenging larvae with per os injection and subdermal injection. We also evaluated the effect of exposing groups of larvae to P. aeruginosa inoculated in their feed and the effect of exposing wounded larvae to P. aeruginosa. We concluded that the mortality rate of Z. morio larvae is higher when P. aeruginosa gets in direct contact with the hemolymph via intracoelomic injection compared to a situation where the bacterium is force-fed. Larvae with an open wound exposed to P. aeruginosa presented higher mortality rate compared to larvae with a wound that was not exposed to the bacterium. We documented too, that cannibalism and scavenging was more prevalent among larvae in a group, when P. aeruginosa is present compared to when it is absent. We discuss hereby different aspects related with the pathogen’s entry routes to insects the complexity of pathogen’s transmission in high population densities and different ways to prevent and/or control P. aeruginosa in mass rearing systems.

The rapid increase in insect production for food and feed both in Europe and elsewhere in the world has led to a need for a coordinated action to assist producers in the diagnosis and management of insect diseases in production stock. Diseases caused by viruses, bacteria, fungi, protozoa and other insect pathogens can be detrimental for reared insects and may cause significant economic loss to producers. Here, we suggest how academia, commercial companies and other insect producers can jointly develop best practice for diagnosing insect diseases early and thereby manage such diseases efficiently. First, we analyse different ways of transmission of insect diseases in closed and semi-closed production facilities. Thereafter we describe four recent cases where companies have requested advice about insect pathogens in their insect stock namely: with giant mealworm Zophobas morio, yellow mealworm Tenebrio molitor, house cricket Acheta domesticus, and with lesser mealworm Alphitobius diaperinus. Our experience dealing with these cases gave us insight to suggest how we should coordinate European activities to establish a service to diagnose and provide advice, and how different European laboratories specialised in insect pathology should collaborate. An important issue will be to educate a new generation of insect pathologists, who with a combination of classical insect pathology methods and the most modern tools can become professionals in diagnosing and managing the various types of insect pathogens.

Opportunistic bacteria are often ubiquitous and do not trigger disease in insects unless the conditions are specifically favorable for bacterial development in a suitable host. In this paper, we isolated and identified a bacterium, Pseudomonas aeruginosa, from the larvae of the giant mealworm Zophobas morio and we studied the possible entry routes by challenging larvae with per os injection and subdermal injection. We also evaluated the effect of exposing groups of larvae to P. aeruginosa inoculated in their feed and the effect of exposing wounded larvae to P. aeruginosa. We concluded that the mortality rate of Z. morio larvae is higher when P. aeruginosa gets in direct contact with the hemolymph via intracoelomic injection compared to a situation where the bacterium is force-fed. Larvae with an open wound exposed to P. aeruginosa presented higher mortality rate compared to larvae with a wound that was not exposed to the bacterium. We documented too, that cannibalism and scavenging was more prevalent among larvae in a group, when P. aeruginosa is present compared to when it is absent. We discuss hereby different aspects related with the pathogen’s entry routes to insects the complexity of pathogen’s transmission in high population densities and different ways to prevent and/or control P. aeruginosa in mass rearing systems.

The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics.

There is growing interest in insects as human food in academia, food and agricultural industries, public institutions and the public at large. Yet many of the words and concepts used to describe these organisms and the human practices surrounding them are still rudimentary, compared to the diversity of the organisms themselves and the existing complexity and rapid evolution of the practices they aim to describe. The goals of this paper are to: (1) show how the roots of the term ‘entomophagy’ and its uses have evolved over time; (2) illustrate some of the term’s problems that necessitate its review; and (3) offer recommendations for use of the term in future research and other practice. Our paper offers a brief historical review of insect eating as described by certain Western cultural sources, explores some of the taxonomic ambiguities and challenges surrounding the category ’insects’, and ultimately argues for more precise and contextual terminology in this both richly traditional and rapidly developing field.