Abstract Worldwide, about 244 million t/yr of waste are produced by canteens and restaurant, of which 4.7 million t/yr are generated at the Italian level. Canteen waste (CW) could be used for feeding larvae of insect to obtain new marketable products (e.g. protein meal, frass and chitin). Black Soldier Fly Larvae (BSFL) are voracious and polyphagous species, and CW is a complete food for them. Furthermore, BSFL are capable to bioaccumulate some heavy metals thus allowing to obtain safe organic frass, but the bioaccumulation in larvae intended for feed purpose needs to be evaluated. The CW was sampled once a month and the sampling was carried out for a year from a local canteen, located in the northern part of Italy. The feeding was conducted in quadruplicate in plastic containers (12 l) and 2,000 g of CW and 2,000 5 days-old larvae were allocated in each box. Each trial ended after 7 days and growth performances were evaluated. The results reported an average dry matter final larval biomass, along the year, of 83.8 ± 46.05 g and an average dry matter frass quantity equal to 199.9 ± 140.32 g. The percentage of dry matter for initial diet was 21.7 ± 14.10, for final larval biomass was 34.3 ± 7.39%, and for the residue of 62.2 ± 17.01%. The initial diet, BSFL before and after feeding, and the residue were sampled and oven dried. Elemental analyses were performed with a mass spectrometer in triplicate for evaluating arsenic, lead, cadmium, and mercury quantities within CW, residues and BSFL before and after feeding. This trial certifies the ability of BSFL to accumulate (BAF > 1) arsenic (average of 0.165 ± 0.1480 ppm), lead (average of 0.238 ± 0.1562 ppm), cadmium (average of 0.077 ± 0.0367 ppm), and mercury (average of 0.008 ± 0.0043 ppm) during feeding, and it proves that the bioaccumulation complies with European legal limits on the amount of heavy metals in larvae.

Abstract Gonimbrasia belina, known as the mopane worm, is a large edible caterpillar in tropical and subtropical regions. However, little is known about the bioecology of this species as influenced by its host trees. This study evaluated the importance of different potential host trees in understanding mopane worms’ behaviour and spatial distribution. To assess their relative importance, the study compared models incorporating various mopane worm host trees and predictor variables. Using the species distribution modelling (SDM) package in R, an ensemble of random forest (RF), support vector machine (SVM), and boosted regression tree (BRT) algorithms were used to assess the spatial extent of mopane worm distribution in Southern Africa. Four host tree-based scenarios were developed to assess their contribution to the relative distribution of the mopane worm i.e. (1) by excluding all the potential host trees as explanatory variables and considering only the environmental variables, (2) focusing on the primary host tree, Colophospermum mopane as an explanatory variable together with the other environmental variables, (3) incorporating all the host trees, including C. mopane and (4) examining all other host trees excluding C. mopane. Results demonstrated that incorporating all host trees enhanced the models’ predictive abilities (mean AUC = 0.87) underscoring the significant impact of the alternative host trees on the mopane worm distribution patterns beyond just the C. mopane. This study highlights the significance of host trees in predicting the behaviour and distribution of mopane worm populations, providing valuable insights and decision-making for mopane worm use as an alternative protein source, conservation efforts, and land management practices.

Abstract With the growing human population the demand for protein is rising and waste production is increasing. Insects can provide a sustainable solution for both problems and produce food (protein and fat) from waste. Our study tested the ability of the black soldier fly (BSF) to reduce agricultural waste and produce a high-value product rich in unsaturated fatty acids. Initially, we tested the diet limitations of the larvae. We tested the composition of the agricultural wastes (brewery and avocado wastes) and the ability of the larvae to grow on them. A mixed diet based on brewery and avocado wastes was composed to increase larval weight and improve their fatty acid composition. The larvae were limited by the protein and water content of the diet (7% and 70%, respectively). The mixed diet that met the requirements of a minimal ratio of protein (7%) and optimal water content (70%), did not improve larval weight but increased the unsaturated fatty acid content. Therefore, using BSF larvae to reduce waste and produce protein is feasible; however, the end product should be considered when composing their diet from a waste mixture.

Abstract Cyanobacteria blooms, a global environmental problem, have caused serious economic and ecological disasters worldwide. Black soldier fly larvae (BSFL) are known to feed and develop on a wide range of feed sources, which makes the use of BSFL bioconversion promising for harvested cyanobacteria. In this study, cyanobacteria were compounded into feedstock by three different treatments, and then BSFL was placed into the substrates to explore the effect of treatments on BSFL growth performance and nutrient yield. It was found that the alterations in the nutrient composition of the substrate and the content of key compounds (vitamin C and microcystin-LR) caused by different treatments were responsible for the different growth performance of BSFL. Difference in larvae digestive enzyme activities caused by changes in treatment processes and substrate moisture content will ultimately affect the BSFL nutrient production. The larvae stress response to different treatment processes demonstrated that the low moisture content environment has an inhibitory effect on the growth of BSFL, and the harvested cyanobacteria treated by the sun-drying treatment process exhibited less interference on BSFL. Through a brief economic assessment, we conclude that cyanobacteria can only produce benefits with the sun-drying treatment process where the substrate moisture content needs to be maintained at 70-80%, wall-breaking and heating treatment and heating treatment processes showed a deficit due to a higher cost and a lower output. This study provides a reference for promoting the utilization of cyanobacteria and proffer instructive significance for the biotransformation of cyanobacteria by BSFL.

Abstract Edible insects are rich in protein and can serve as a significant source of vitamins and minerals. The house cricket (Acheta domesticus) stands out as one of the most nutritious edible insects. In various parts of the world, crickets are consumed roasted, baked, fried, boiled and in the form of cricket flour, a powder of dried and ground crickets. In Europe, processed animal proteins derived from eight insect species (including A. domesticus) have received authorization for use in fish, pig and poultry feed. Therefore, the development of a method for detecting house crickets is essential to verify product compliance and provide accurate labelling information to the end user. In this study, we have established a real-time PCR assay for the specific detection of house crickets. This method is based on the amplification of a mitochondrial fragment that codes for cytochrome b. We assessed its specificity by testing it against 39 other insect species, 7 plant species and 31 other animal species. Furthermore, we successfully evaluated the amplification efficiency, sensitivity, robustness, applicability on commercial samples and transferability to a second laboratory.

Abstract Poultry industry is one of the fastest growing agri-businesses in the world. However, the usage of expensive soybean meal and fishmeal as poultry feed ingredients is making it less profitable and environmentally unsustainable. Insects are becoming more popular as an alternate protein source in poultry feed because they are more sustainable, cost-efficient and eco-friendly than most of the conventional poultry feed sources. In the present study, we replaced 4%, 8% and 12% soybean meal with blow fly, Chrysomya megacephala (Calliphoridae: Diptera) larvae and evaluated its impact on growth performances, hematological parameters, intestinal morphometry and meat quality of Ross 308 broiler. For comparison, we also evaluated commercially available full fat Hermetia illucens (Stratiomyidae: Diptera) larvae. Three hundred and fifty 1-day-old chicks with initial weight of 40.28 g/chick were randomly divided into seven experimental diets (5 pens per treatment and 10 birds per pen). All the dietary treatments were isocaloric and isonitrogenous, meeting the nutrient requirements of the broilers. The results revealed that the broiler fed on 12% C. megacephala or H. illucens had significantly higher () live weight, average daily weight gain and better feed conversion ratios. The diets containing 12% C. megacephala or H. illucens significantly improved the blood haematology and serum bio-chemistry in the broiler. The gut histological indices of jejunum and ileum such as villus height (Vh), crypt depth (Cd), villus width (Vw), and Vh/Cd ratios also improved by the feeding of 12% C. megacephala and H. illucens diets. The broiler fed on 12% H. illucens diet showed higher L* (lightness) and a* (redness), while those fed on 12% C. megacephala showed higher b* (yellowness) in breast meat (Pectoralis major). Both species performed equally well in growth performance, haematology, serum bio-chemistry, gut histology and meat quality. It was concluded that replacement of soybean meal with 12% C. megacephala or H. illucens larvae improves the growth performance, blood haematology, gut histology and meat color and lightness traits of broiler and thus can be used as an alternate source of protein in broiler feed.

Abstract As the industrial insect production sector is rapidly growing, the high production cost of insects forms a constraint for the further growth of the insect industry. One of the main factors that greatly contributes to the total insect production cost and affects the profitability of insect farms is feed costs. Various agricultural by-products have been successfully evaluated and proposed as low-cost, alternative, insect feedstocks. In this context, this study evaluates a variety of Greek agricultural by-products as feeding substrates for Zophobas morio (F.) (Coleoptera: Tenebrionidae) larvae. More specifically, eleven agricultural by-products derived from the seed cleaning process of barley, oats, peas and vetch and the production of cotton, sugar beet and sunflower, were utilized singly and as components of compound isonitrogenous diets at two nitrogen levels (2.7% and 3.2% on dry matter basis). The results showed that larvae reared on sunflower meal, oat and barley (class II) by-products performed well in terms of larval growth and survival. In contrast, for most other diets tested high mortality rates were recorded, indicating the necessity for the formulation of diets that meet the nutritional requirements of the larvae. Our study highlights the potential of locally available by-products for the rearing of Z. morio larvae and contributes to determining their nutrient requirements.

Abstract Black soldier fly (BSF) larvae are exceptionally efficient at converting otherwise unusable waste products, while having a minimal impact on the environment. To optimise the production of BSF larvae, selective breeding could be used. With selective breeding, the best individuals to breed the next generation are selected, for example, with a breeding goal. This study aimed to make the first step towards defining such a breeding goal, by estimating the economic values (EV) of traits that are important for the production of BSF larvae. EV were estimated for larval mass on day 15, feed intake, feed conversion ratio, growth rate, dry mass-, protein- and fat content, development time, eggs per fly, egg hatching rate, and larval mortality. A bio-economic model was used to estimate the profit of a BSF production system that produces 1000 kg of wet larvae at harvesting. The EV of a trait was estimated as the increase in profit when the trait value was increased by 10%, whilst the other traits remained unchanged. EV were expressed per 10% increase, and changes in revenues and costs were specified. The results showed traits with the highest EV were related to composition (dry mass-, and protein-content) and growth (larval mass, development time, growth rate). Traits related to reproduction and flies (development from pupa to fly, number of eggs) had the lowest EV. Due to the lack of information on genetic parameters, the EV are expressed per +10% of the mean value of a trait. In the future, when more information is available, the EV should be expressed per genetic standard deviation. In conclusion, this is the first study that estimated EV for an insect species. The results are a first step towards developing a more sophisticated breeding program for optimizing BSF production.

Abstract Lab-grown insect meat is a promising alternative to traditional livestock for sustainable food production. This review paper aims to provide a comprehensive overview of the current state of knowledge regarding lab-grown insect meat, emphasizing key aspects such as life cycle assessment, insect cell culture history, technological advancements, and bio-robotics in insect cell culture. Comparisons and challenges between insect and mammalian/avian cell culture methodologies are presented. The nutritional content of edible insects (proximate, amino acid, mineral, and vitamin content) and the potential health benefits of consuming insect meat are discussed. The paper also explores embryonic and adult myogenesis processes in insect cells, as well as the significance of insect body fat and muscle cells in culture. Applications of insect cell culture in various fields, such as food production and pharmaceutical development, are presented. Moreover, the potential occurrence of mutations in lab-grown insect cells is examined. Lastly, the review addresses the drawbacks and limitations of insect labriculture, discussing factors such as scalability, cost-efficiency, and public acceptance. Overall, this comprehensive review provides essential insights into the chemical and biological aspects of lab-grown insect meat, paving the way for further research and development in this emerging field. This article is the first review article reporting the chemical and biological insights of lab-grown insect meat.

Abstract Defatted larvae meal (dLM), specifically from black soldier flies, could help overcome the animal protein gap. As insect production is an emerging sector, current economic research is scarce and very diverse. Thus, the aim of this research was to develop a simulation model that enables the analysis of full industrial scale costs of producing dLM and to provide insight in the distribution of these costs in the insect supply chain. The deterministic supply chain model is built on three modules, technical, transition and economic module, which all follow a previously defined supply chain structure and allow to extract quantity and price information for intermediate or final products. The model was parameterized and checked for plausibility in multiple consultation rounds with the INSECTFEED consortium and business partners. Additionally, model behaviour was checked with scenario, sensitivity, and break-even price analyses. In the default situation 5.57 tDM raw substrate and 26.7 million neonates are required to produce 1 tDM dLM for a price of €5,116/tDM. Most costs are added in the raw substrate delivery (€1,952/tDM) and production and collection (€821/tDM) step. Important cost factors are the raw substrate (€1,939/tDM) and building and inventory (€1,459/tDM). Parameters with high relative response rate towards the price of dLM are the feed conversion rate, dry matter percentage of larvae, raw substrate price, larvae density, labour wage and growth rate. To reach break-even prices for substituting fish meal with alive grown larvae (AGL) (€1,318/tDM AGL), improving production parameters is not sufficient. Just changing prices of raw substrate to −€78/tDM or frass to €1,175/tDM would enable a profitable operation. However, these are not deemed as realistic in mass production. Although there is some insecurity in data, the model results are the most realistic representation of industrial scale production amounts and costs.