Diversity and Use of Edible Grasshoppers, Locusts, Crickets, and Katydids (Orthoptera) in Madagascar

The complete mitochondrial genome of Phymateus saxosus (Coquerel, 1861) (Orthoptera: Pyrgomorphidae) and phylogenetic analysis

Phymateus saxosus is a member of the family Pyrgomorphidae, Orthoptera. In this study, the complete mitochondrial genome (mitogenome) of P. saxosus was determined and analyzed. Assembled mitogenome sequence of P. saxosus is 15,672 bp in size, containing 37 genes and a control region. The gene orientation and arrangement of P. saxosus are identical to other species in the Pyrgomorphoidea family. The overall nucleotide composition is as follows: A (43.6%) > T (30.2%) > C (16.1%) > G (10.1%). Phylogenetic analysis suggested that P. saxosus forms sister groups with P. morbillosus, and the monophyly of Pyrgomorphidae is supported. In general, this study provided valuable genetic information for P. saxosus and explored the phylogenetic relationships in the family Pyrgomorphidae.

Wild Foods Are Positively Associated with Diet Diversity and Child Growth in a Protected Forest Area of Madagascar

Background

Concurrent losses in biodiversity and human dietary diversity are evident in Madagascar and across many food systems globally. Wild food harvest can mitigate nutrition insecurities but may also pose species conservation concerns.

Objectives

This study aimed to examine the association of wild plant and animal species consumption during hunger season with diet diversity and child growth near the Alandraza-Agnalavelo protected forest in Southwestern Madagascar. Second, we studied the conservation status of the consumed wild plants.

Methods

Methods from public health nutrition (24-h recall dietary intake, anthropometry using World Health Organization [WHO] Growth Standards), ethnobotany, and forest ecology (ecologic studies of abundance, habitat preference, associated species, food chemistry assays, and species richness) were applied.

Results

Malnutrition in children (n = 305) was highly prevalent: stunting (32.3%); wasting (18.8%); and low-dietary diversity (4% meeting WHO minimum dietary diversity threshold). Animal foods were consumed in small quantities, providing <10% of Dietary Reference Intakes for all limiting nutrients. Twenty-two wild plant species were consumed during hunger season, prominently tubers (Dioscoreaceae), and leafy greens (Asteraceae, Blechnaceae, Portulacaceae, and Solanaceae). Eight of the 9 target species were identified as abundant and "Least Concern," whereas Amorphophollus taurostigma was abundant and "Vulnerable." Regression modeling showed wild food consumption was associated with an increased household dietary diversity score [β = 0.29 (0.06 standard error); P < 0.001], and total wild animal foods positively correlated with height-for-age Z score [β = 0.14 (0.07 standard error); P = 0.04].

Conclusions

Wild plant and animal foods may be an important element of food systems to support human nutrition while maintaining ecosystem viability.

Edible Insects: A New Sustainable Nutritional Resource Worth Promoting

Edible insects are a highly nutritious source of protein and are enjoyed by people all over the world. Insects contain various other nutrients and beneficial compounds, such as lipids, vitamins and minerals, chitin, phenolic compounds, and antimicrobial peptides, which contribute to good health. The practice of insect farming is far more resource-efficient compared to traditional agriculture and animal husbandry, requiring less land, energy, and water, and resulting in a significantly lower carbon footprint. In fact, insects are 12 to 25 times more efficient than animals in converting low-protein feed into protein. When it comes to protein production per unit area, insect farming only requires about one-eighth of the land needed for beef production. Moreover, insect farming generates minimal waste, as insects can consume food and biomass that would otherwise go to waste, contributing to a circular economy that promotes resource recycling and reuse. Insects can be fed with agricultural waste, such as unused plant stems and food scraps. Additionally, the excrement produced by insects can be used as fertilizer for crops, completing the circular chain. Despite the undeniable sustainability and nutritional benefits of consuming insects, widespread acceptance of incorporating insects into our daily diets still has a long way to go. This paper provides a comprehensive overview of the nutritional value of edible insects, the development of farming and processing technologies, and the problems faced in the marketing of edible insect products and insect foods to improve the reference for how people choose edible insects.

Does space matter? Estimation and evaluation of required space for commercial mass culture of grasshoppers (Acridoidea: Orthoptera)

A space-dependent mortality assay was performed on thirty-one short-horned adult grasshopper species (Acridoidea: Orthoptera) to estimate the space required for mass culture of acridids in captivity. Our findings show that acridids have a multidimensional mortality mode at different densities. The correlations between density and mortality of acridids in rearing units follow a sigmoidal curve. Acridid mortality significantly increases with individual numbers up to a threshold, after which mortality does not change even if the density increases further. A log-logistic sigmoidal function expresses the dose (density)-response (mortality) relationship in the majority of acridid species. Mortality of acridids at variable densities does not necessarily correspond with the body-mass of the insects, indicating that mortality is a body-mass independent event. As a ready reference, a utility chart has been prepared, providing the necessary conversion factor for estimating space for a given number of acridids. The present information will be helpful for commercial grasshopper farming in captivity.

Cultural significance of locusts, grasshoppers, and crickets in sub-Saharan Africa

BACKGROUND

In sub-Saharan Africa, there is a wealth of information about insects which is often only orally available. The purpose of the study was to remedy this shortcoming and make an overview of how orthopteran species are utilised, perceived and experienced in daily life across sub-Saharan Africa.

METHOD

Ethno-entomological information on Orthoptera in sub-Saharan Africa was collected by (1) interviews with more than 300 people from about 120 ethnic groups in 27 countries in the region; (2) library studies in Africa, London, Paris and Leiden; and (3) using web search engines.

RESULTS

More than 126 species of crickets, grasshoppers, and locusts have been identified as edible in sub-Saharan Africa. Some toxic species, such as Zonocerus spp., are eaten by some groups who use processing and detoxifying techniques. The katydid Ruspolia differens is very popular as food in central and eastern Africa and is captured by indigenous and commercial methods. Vernacular names refer to their morphology, behaviour, characteristics or the beliefs associated with the insect. The aposematic pyrgomorphid species, such as Zonocerus spp., are often used as medicine. Children play with grasshoppers, by for instance herding them like cattle, and they consider cricket-hunting for food as a game. The doctrine of signatures probably plays a role, as crickets, because of their chirping, are used to improve the sound of a music instrument, or as medicine to treat earache. Locust plagues are considered a punishment which requires repentance, but also an opportunity to acquire food. Proverbs and stories relate to using the orthopterans as food or to the underground lives of the crickets. Possible explanations are given as to why so many practices, beliefs and stories about orthopterans are so widespread in sub-Saharan Africa. The relevance of recording such ethno-entomological practices is discussed.

CONCLUSION

Grasshoppers, locusts and crickets, although they may be agricultural pests, are very popular as food. They are also used in medicine, and as toys, and they play a role in religion, art and literature.

Nature's "Free Lunch": The Contribution of Edible Insects to Food and Nutrition Security in the Central Highlands of Madagascar

Edible insects are a healthy, sustainable, and environmentally friendly protein alternative. Thanks to their quantitative and qualitative protein composition, they can contribute to food security, especially in Africa, where insects have been consumed for centuries. Most insects are still harvested in the wild and used for household consumption. So far, however, little attention has been paid to insects’ real contribution to food security in low-income countries. Entomophagy, the human consumption of insects, is widespread in many rural areas of Madagascar, a country, at the same time, severely affected by chronic malnutrition. This case study was carried out in a region where entomophagy based on wild harvesting is a common practice and malnutrition is pervasive. The data were obtained in 2020 from a survey among 216 households in the rural commune of Sandrandahy in the central highlands of Madagascar. Descriptive statistics, correlation, and regression analysis were used to show the relative importance of insects for the local diet and to test various hypotheses related to food security. Results show that insects contribute significantly to animal protein consumption, especially in the humid season, when other protein sources are scarce. They are a cheap protein source, as much esteemed as meat by the rural population. There are no significant differences in the quantities of insects consumed by poorer versus richer households, nor between rural and urban households. Insect consumption amounts are strongly related to the time spent on wild harvesting. The importance of edible insects for poor, food-insecure rural areas and how entomophagy can be promoted for better food and nutrition security are discussed.

Drivers of insect consumption across human populations

Discussions regarding entomophagy in humans have been typically led by entomologists. While anthropologists devote much time to understanding diverse human subsistence practices, historical and cultural variation in insect consumption remains largely unexplained. This review explores the relation between variable ecologies, subsistence strategies, and social norms on insect consumption patterns across past and contemporary human populations. Ecological factors, such as the nutritional contribution of edible insects relative to those of other foraged or farmed resources available, may help explain variation in their consumption. Additionally, our evolved social learning strategies may help propagate social norms that prohibit or prioritize the consumption of some or all edible insects, independent of their profitability. By adopting a behavioral ecological and cultural evolutionary approach, this review aims to resolve current debates on insect consumption and provide directions for future research.

Novel Foods and Sustainability as Means to Counteract Malnutrition in Madagascar

Although the trends of international reports show an increase in overweight and obesity, even in developing countries, there are still areas of the world, such as Sub-Saharan Africa, strongly affected by undernutrition. Specifically, in Madagascar, the percentage of stunted children under 5 is extremely high. Furthermore, the COVID-19 pandemic is expected to increase the risk of all forms of malnutrition, especially in low-income countries, including Madagascar, with serious intergenerational repercussions. This narrative review aims at investigating eating habits and cooking methods of the Malagasy population, addressing sustainable healthy diets through promotion of novel foods. While novel foods are a recent concept, there are data that describe how they may contribute to counteract food insecurity and malnutrition considering context and place. Efforts to promote native, traditional foods as Moringa oleifera, an indigenous plant in Asia and Africa including Madagascar, rich in protein and micronutrients, as well as edible insects, alternative sustainable source of protein, lipids, iron, and zinc, would provide not only nutritional but also cultural and economic benefits. The potential synergies between food traditions and agroecology have the potential to impact health addressing larger issues of sustainability and food security. Regional, national, and international policies are needed to develop and support one health approach actions.

Edible Crickets (Orthoptera) Around the World: Distribution, Nutritional Value, and Other Benefits-A Review

Edible crickets are among the praised insects that are gaining recognition as human food and livestock feed with a potential of contributing to food security and reduction of malnutrition. Globally, the sustainable use of crickets as food or feed is undermined by lack of information on the number of the edible crickets, the country where they are consumed, and the developmental stages consumed. Furthermore, lack of data on their nutritional content and the potential risks to potential consumers limits their consumption or inclusion into other food sources. We reviewed published literature on edible cricket species, countries where they are consumed, and the stage at which they are consumed. We further reviewed information on their nutritional content, the safety of cricket consumption, and the sensory qualities of the edible crickets. We also looked at other benefits derived from the crickets, which include ethnomedicine, livestock feed, pest management strategies, contribution to economic development, and livelihood improvement, particularly in terms of use as food preservatives and use within music, sports, and cultural entomology. Lastly, we reviewed information on the farming of edible crickets. In this review, we report over 60 cricket species that are consumed in 49 countries globally. Nutritionally, crickets are reported to be rich in proteins, ranging from 55 to 73%, and lipids, which range from 4.30 to 33.44% of dry matter. The reported amount of polyunsaturated fatty acids (PUFA) is 58% of the total fatty acids. Edible crickets contain an appreciable amount of macro- and micro-mineral elements such as calcium, potassium, magnesium, phosphorus, sodium, iron, zinc, manganese, and copper. Also, the crickets are rich in the required amount of vitamins such as B group vitamins and vitamins A, C, D, E, and K. Overall, the cricket species examined in this review are safe to be consumed, and they display high proximate content that can replace plant and livestock products. The crickets play valuable roles in contributing to the economies of many countries and livelihoods, and they have medicinal and social benefits. This review is expected to promote greater recognition of crickets as a source of food, feed, and other benefits in the world and encourage up-scaling by farming them for sustainable utilization.

Differential responses of the antennal proteome of male and female migratory locusts to infection by a fungal pathogen

The narrow host range entomopathogenic fungus, Metarhizium acridum, is an environmentally friendly acridid specific pathogen used for locust control. The locust is capable of responding within hours of infection, however, little is known concerning how the locust detects the pathogen. Here, we have identified 3213 proteins in the infected antennal proteome of the migratory locust, Locusta migratoria. iTRAQ comparative analyses of antennal proteomes identified 194 differentially abundant proteins (DAPs) between uninfected and infected males, 218 DAPs between uninfected and infected females, and 240 DAPs between infected males and infected females. In relation to olfaction, a total of 29 chemosensory proteins (CSPs), 9 odorant binding proteins (OBPs), 31 odorant receptors (ORs), and 8 ionotropic receptors (IRs) were differentially abundant after M. acridum infection, with a subset of 12 proteins found in both infected male and female antennae not present in uninfected individuals. The time course of the gene expression profiles of olfaction related DAPs were investigated by quantitative real-time PCR (qRT-PCR). Our data indicate significant changes in the antennal proteomes of male and female locusts in response to a microbial pathogen, highlighting the potential participation of olfactory processes in pathogen detection and response. BIOLOGICAL SIGNIFICANCE: The ability of an organism to detect microbial pathogens is essential for mounting a response to mitigate the spread of the infection. Using iTRAQ-based proteomic analyses changes in the protein repertoire of the antennae of male and female locusts in response to infection by a host-specific pathogen were determined. These data show proteomic alterations that are also sex-specific, identifying members of olfactory pathways that are modified in response to infection. Our data identify antennal and related olfactory proteins that are candidates for mediating host detection of pathogens, and that may contribute to subsequent behavioral and/or immune responses of the host to the infection challenge.

Insects Used as Food and Feed: Isn't That What We All Need?

This Special Issue of Foods explores different aspects of how insects can be used as a novel resource for food and feed. Some contributions deal with questions of acceptability and legality, others tackle problems related to innovative techniques in processing and marketing food, and yet another group of papers highlights the use of insects and their bio-active products in the context of promoting human health. The collective aim of the contributions by the researchers from at least 20 countries is to examine whether the use of insects—be it for food, feed, or therapeutic purposes—has a future. We conclude that positive aspects undoubtedly exist regarding the nutritional and pharmacological value of various insect species but that environmental and bio-functional issues could even outweigh the nutritional value of food insects.

Nutritional Composition of Apis mellifera Drones from Korea and Denmark as a Potential Sustainable Alternative Food Source: Comparison Between Developmental Stages

We compared nutrient compositions of honey bee (Apis mellifera) drones of different developmental stages from two different populations-the Italian honey bee reared in Korea and Buckfast bees from Denmark. Analyses included amino acid, fatty acid, and mineral content as well as evaluations of antioxidant properties and haemolysis activities. The compositions of total amino acids, and thus protein content of the insects, increased with development. A similar trend was observed for minerals presumably due to the consumption of food in the adult stage. In contrast, total fatty acid amounts decreased with development. Altogether, seventeen amino acids, including all the essential ones, except tryptophan, were determined. Saturated fatty acids dominated over monounsaturated fatty acids in the pupae, but the reverse held true for the adults. Drones were found to be rich in minerals and the particularly high iron as well as K/Na ratio was indicative of the nutritional value of these insects. Among the three developmental stages, adult Buckfast drones exhibited the highest antioxidant activity. Bearing in mind the overall high nutritional value, i.e., high amino acids, minerals and less fatty acids, late pupae and adult drones can be useful for human consumption while the larvae or early pupal stage can be recommended as feed. However, owing to their relatively high haemolysis activity, we advocate processing prior to the consumption of these insects.