Taxonomic, economic and gastronomic analysis of some edible insects of the Order Hemiptera from Mexico

In some states of Mexico, 14 families, 51 genera and 146 species of edible insects of the order Hemiptera were registered; they belong to the families: Belostomatidae (3 genera, 7 species), Corixidae (6-13), Notonectidae (1-2), Lygaeidae (1-1), Coreidae (9-20), Pentatomidae (5-58), Rhopalidae (1-1), Pyrrhocoridae (1-1), Cicadidae (7-22), Dactylopiidae (1-4), Membracidae (4-7), Aethalionidae (1-6), Fulgoridae (1-3) and Kerridae (1-1). The Pentatomidae family presents the highest number of genera (14) and species (57). Their distribution by localities is indicated; these correspond to the municipalities of the different states so far sampled. Likewise, we report various forms in which they are prepared and the economic importance of, for example, the ‘Jumiles’ of the genus Euschistus and Edessa that are widely looked for, collected, accepted as part of the diet, consumed and marketed, is discussed.

How many people on our planet eat insects: 2 billion?

The estimated figure of two billion people consuming insects mentioned in the 2013 FAO/WUR report about edible insects has been cited many times over. This editorial asks four questions to determine the accuracy of the estimated figure: how to define an ‘insect-eating’ person; which percentage of the population eats insects; how does insect consumption develop over time; and how to define an edible insect? Our conclusion is that it is difficult to establish an exact figure of how many people eat insects globally and that the much cited 2 billion figure in the FAO/WUR report must be an overestimation.

Insects in Atlantic salmon (Salmo salar) diets – comparison between full-fat, defatted, and de-chitinised meals, and oil and exoskeleton fractions

The present study investigated the effect of meals and fractions of black soldier fly larvae (BSFL; Hermetia illucens) in diets for Atlantic salmon (Salmo salar) on the physical quality of feed pellets, nutrient utilisation, and growth performance. Six extruded diets were produced: control diet (CD); full-fat BSFL meal diet (IM); defatted BSFL meal diet (DFIM); de-chitinised BSFL meal diet (DCIM); BSFL oil diet (IO) and BSFL exoskeleton diet (EX). The full-fat, defatted and de-chitinised meals replaced 15% of protein in the control diet. An eight-week study was conducted using salmon with average 28 g initial weight. The full-fat and de-chitinised meals in the diets numerically reduced pellet hardness, expansion, and water stability. The full-fat and de-chitinised meals improved growth rate of salmon, whilst defatted meal, oil and exoskeleton supported similar growth performance as the control. Feed intake and growth rate of fish fed full-fat meal diet were higher than those fed the other insect diets, but defatted meal gave a better feed conversion ratio than full-fat meal. Defatted meal, de-chitinised meal and exoskeleton reduced protein digestibility in fish, however; defatted meal increased the digested protein retention. In conclusion, use of full-fat BSFL meal improved feed intake and growth rate of salmon when replacing 15% of dietary protein. The present results suggest that less processed fullfat form of BSFL is more optimal in diets for salmon and further processing to remove lipid or exoskeleton fractions would only lead to an additional cost.

Consumer attitude and acceptance toward fish fed with insects: a focus on the new generations

Since global demand for aquaculture products is expected to increase dramatically in the near future, policymakers and companies are considering the adoption of insect-based feed, which is more economically viable and environmentally sustainable than fish or vegetable-based meals currently used. Nonetheless, fish farmed with insects are still perceived as innovative products by consumers, and further studies exploring these demand-side concerns must be conducted to make sure a market for such products exists. This study focuses on the factors that can favour the acceptance of farmed fish fed with insects of a sample of young Italians. In particular, within the theoretical framework adopted in this analysis, we let acceptance be expressed by different dimensions, each potentially influenced by individual factors, such as socio-economic characteristics, as the provision of information on the nutritional and environmental benefits of insect-based feed for aquaculture, and as consumer psychometric indicators. In this respect, we use the by-dimensional definition of environmental attitude proposed by environmental psychologists, that considers attitude toward environmental protection and toward nature. In this survey, we reached 482 consumers, aged less than 40, using social networks. A Factor Analysis was performed to identify the different dimensions of the acceptance process. We then applied the Rasch model on consumers’ reported behaviours toward environmental protection or nature to retrieve their environmental attitudes. We performed a Seemingly Unrelated Regression to assess the importance of socio-demographic, information, and psychometric variables on the different dimensions of acceptance. Results indicate that the use of psychometric variables to study the acceptability of an innovative food product seems particularly appropriate. In addition to the role of environmental attitude, acceptance is also explained by some socio-demographic variables, with men and younger consumers being more inclined to accept the product. Acceptance is also higher among informed respondents, confirming the importance of reducing information asymmetries.

Effect of carrot supplementation on nutritional value of insects: a case study with Jamaican field cricket (Gryllus assimilis)

The fortification of feed is known to be a useful tool to manipulate the nutritional value of insects. This study aimed to reveal the effect of carrot supplement duration on the basic nutrients, fatty acid profile, carotenes, and tocopherols. Jamaican crickets (Gryllus assimilis) were provided with chicken feed supplemented with carrots ad libitum for 0, 3, 7, 14 and 60 days prior to harvest. The supplementation increased the levels of α-carotene and β-carotene in the insects. The content of carotenoids did not significantly differ between groups fed carrot for 14 (α-carotene = 13.7 μg/g DM; β-carotene = 34.6 μg/g DM) and 60 days (α-carotene = 15.2 μg/g DM; β-carotene = 37.2 μg/g DM), suggesting that the capacity of the insects to store carotenes is limited. Some carotenoids (α-carotene = 5.4 μg/g DM; β-carotene = 12.8 μg/g DM) were found in crickets given carrot supplementation for only 3 days prior to harvest. Carrot supplementation affected the fatty acid profile of the insects. Crickets fed carrot for 60 and 14 days contained lower levels of SFA (32.00 and 32.74% of total fatty acids respectively) and higher levels of PUFA (33.06 and 32.49% of total fatty acids respectively) in comparison with insects fed for 0, 3 or 7 days. No influence of carrot supplementation was observed in feed conversion, tocopherols and basic nutrients (proteins, lipids, ash). Conclusively, the paper showed some beneficial effects of carrot supplementation, when the highest levels of carotenoids were reached by 14 and 60 days of carrot provision. Therefore, the whole life supplementation seems to be not necessary to reach the increased content of carotenoids in crickets.

Entomophagy in Gabon across the African context

Entomophagy is well established in the food habits of Africa; however, country-wide knowledge remains limited for several countries, including Gabon. Here, two surveys on entomophagy were conducted in Gabon through face-to-face interviews. The first survey collected information on insect eating habits from 169 potential consumers. Edible insects formed part of the diet of most Gabonese people, with more than 60% of consumers within participants, and were particularly common among the Teke ethnic group (93%). Familiarity with edible insects was influenced by culture and family, but not by gender or study level. The second survey focused on edible insect species and their host plants, by interviewing a sample of 113 both villagers and retailers. Seventy-five species of insects from six insect orders (Coleoptera, Hemiptera, Isoptera, Lepidoptera, Odonata and Orthoptera) were consumed in Gabon, and were collected from 48 species of host plant. Many insects were formerly reported in the literature related to entomophagy; however, 13 species were newly reported as edible in this study: Bidessus batekensis, Bunaeopsis licharbas, Copelatus ateles, Copelatus confinis, Copelatus fizpaci, Copelatus tondangoyei, Gonobombyx angulata, Gonometa titan, Hydrocyrius columbiae, Oxychirus semisericeus, Philobota sp., Psara sp. and Ptyelus flavescens. Consequently, these surveys highlighted that entomophagy is common in Gabon. However, strategies to promote edible insects are needed to have a significant impact on food issues in Gabon (e.g. food insecurity and dependence on foreign food supplies). Additional researches on entomophagy in Gabon are required to further develop these strategies.

Insects as a food source for indigenous communities in Colombia: a review and research perspectives

Insects have been used worldwide as a source of food, and edible species are eaten both as immature (eggs, larvae, pupae, and nymphs) and in some cases as adults. In this regard, several scholars and researchers seek to promote an alternative entomological trend and highlight the potential of insects as a high-quality nutritional option. The consumption of various edible species contributes to the nutritional health of indigenous, rural peoples, as well as those individuals who live in urban areas and use this kind of food resource, in accordance with insects’ seasonal abundance. Colombia, due to its sociocultural origin, stands out as one of the Latin American countries that have the habit of consuming insects by presenting both biological and ethnic diversity. However, the use and diversity of edible insects in the country have been little studied. This review summarises the current status related to the knowledge of insects as food resources, with emphasis on ethnic groups established in the country. In Colombia, 69 edible insect species are currently reported, distributed in 49 genera, 27 families and 10 orders, and ingested by approximately 13 ethnic groups belonging principally to the Amazon and Caribbean regions. Guidelines and protocols are provided to establish research priorities in the study and use of edible insects in Colombia. In this way, the proposal of a general framework for the study and conservation of edible insect species, integrating a bioecological, socio-economic and institutional approach, will provide new perspectives for food security in this era of world food scarcity, and can play an interdisciplinary role (forestry, traditional medicine, agriculture, livestock) in mitigating the current global food crisis.

Impact of age, sex, and size on the thermal tolerance of the adult black soldier fly (Diptera: Stratiomyidae)

Thermal stresses from both environmental conditions and organismal crowding are common in mass production of the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae). In this study, upper and lower critical thermal (CT) limits (i.e. knockdown CTmax and CTmin) for the adult black soldier fly were determined. Impacts of size, age, and sex on these critical temperatures were also assessed. The CTmax ranged from 45.0-51.0 °C with larger and older adults having a ~1 °C higher CTmax than smaller and younger adults. However, no differences in the CTmax were found between sexes, regardless of age or size. The CTmin ranged from 8.0 to 13.0 °C with larger and older females having a ~1 °C higher CTmin than males and smaller or younger females. While reporting the upper and lower critical temperatures, this study also revealed the thermal breadth (i.e. the range of body temperatures over which organisms can locomote) for adult black soldier flies across age, sex, and size. Based on these data, and when recognising not all fly populations are the same, mass-rearing facilities should determine the CTmax and CTmin for their fly population in order to optimise mating and fertile egg production, and ultimately maximise profits and sales. One degree of temperature can be the difference between success and failure in industrialised facilities.

Antioxidant activity of Gryllus assimilis meal hydrolysed by Aspergillus oryzae proteases

The consumption of insects is an alternative protein source of a high nutritional value, in comparison to other traditional animal and vegetable proteins, and is suitable for food and as animal feed. This work aimed to study the antioxidant activity of cricket meal (Gryllus assimilis) partially hydrolysed by proteases from a Aspergillus oryzae, which was cultivated in the cricket meal. The cricket meal showed great potential for obtaining protease from A. oryzae, with an average enzymatic activity of 112±8 U/g of dry substrate after 96 h of fermentation. The enzymatic extract applied to the cricket meal increased its antioxidant properties, increasing the reduction of the 2,2-diphenyl-1-picrylhydrazyl radical by 2 times, compared to non-hydrolysed cricket meal. These initial results are promising, demonstrating the benefits of the partial hydrolysis of cricket meal.

Impact of ergot-contaminated feed on yellow mealworm larvae performance and diet preference

This study aimed to determine if ergot alkaloids (EA) would accumulate in yellow mealworm larvae (YML, Tenebrio molitor) when present in their diets and investigate effects on production and survival. Larvae were reared on one of four diets: a control, low, medium, and high containing 63, 3,863, 8,471 and 15,316 μg/kg total EA, respectively. Each diet had five replicates with 150 YML per replicate totalling 3,000 for the 21-day trial. Initial and final weights of the feed and larvae were collected. Ergot alkaloid concentrations in YML at d 21 were 32.6, 94.0 and 155.5 μg/kg in the low, medium, and high treatments respectively, with none detected in those fed the control diet. The frass from YML fed the control, low, medium and high diets contained 18, 364, 1,094, and 1,424 μg/kg total EA, respectively. Feed intake was reduced in larvae fed the low, medium and high treatments relative to the control at 23.3-24.9 g/21 d compared to 30.1 g in the control (P=0.02). Feed-to-gain ratios, average daily gain, and final body weights did not differ among treatments (P>0.05). The larvae did not display any preference for diets when allowed to choose between the four diets (P>0.05). Larvae accumulated only low levels of EA from their diets and although feed intake was depressed, growth was maintained. Further research is required to determine the safety of yellow mealworm reared on EA-contaminated diets.