Different studies have shown that insect meals can partially or completely replace the fish and soya bean meals that are commonly used in aquaculture. However, information is lacking on the amino acid and fatty acid contents and digestibility of different insect meals. Moreover, we evaluated different proportions of insect diets and determined how these affected the nutritional values of insect meals. Our purpose was to clarify these aspects and consider the availability of protein, amino acids, lipids and fatty acids in insect meals in fish nutrition. Generally, insect meals have higher indispensable amino acid contents than other meal types, with contents closely related to those in fish meal. Insect meal can be an important source of essential amino acids such as methionine, with contents ranging between 0.47 and 4.03 g 100 g 1 sample. These values are higher than those reported for other animal and plant meals. In addition, insects are also good sources of lipids and fatty acids, and the amounts and types of fatty acids vary according to the species, stage of development and type of feed. Moreover, the additional nutritional value of insect meal includes compounds such as chitin, which is primarily considered a fibre but also contains nitrogen and amino acids. Insect peptides with activity against pathogenic microflora provide secondary biological effects, which may significantly improve animal health.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/raq.12281

Insect meals in fish nutrition

Background Insects are a living resource used for human nutrition, medicine, and industry. Several potential sources of proteins, peptides, and biopolymers, such as silk, chitin, and chitosan are utilized in industry and for biotechnology applications. Chitosan is an amino-polysaccharide derivative of chitin that consists of linear amino polysaccharides with d -glucosamine and N-acetyl- d -glucosamine units. Currently, the chief commercial sources of chitin and chitosan are crustacean shells that accumulate as a major waste product from the marine food industry. Existing chitin resources have some natural challenges, including insufficient supplies, seasonal availability, and environmental pollution. As an alternative, insects could be utilized as unconventional but feasible sources of chitin and chitosan. Scope and approach This review focuses on the recent sources of insect chitin and chitosan, particularly from the Lepidoptera, Coleoptera, Orthoptera, Hymenoptera, Diptera, Hemiptera, Dictyoptera, and Odonata orders. In addition, the extraction methods and physicochemical characteristics are discussed. Insect chitin and chitosan have numerous biological activities and could be used for food, biomedical, and industrial applications. Key findings and conclusions Recently, the invasive and harmful effects of insect species causing severe damage in agricultural crops has led to great economic losses globally. These dangerous species serve as potential sources of chitin and are underutilized worldwide. The conclusion of the present study provides better insight into the conversion of insect waste-derived chitin into value-added products as an alternative chitin source to address food security related challenges.

Recent insights into the extraction, characterization, and bioactivities of chitin and chitosan from insects.

Edible insects have been used as an alternative protein source for food and animal feed, and the market size for edible insects has increased. Tenebrio molitor larvae, also known as mealworm and yellow mealworm, are considered a good protein source with nutritional value, digestibility, flavor, and a functional ability. Additionally, they are easy to breed and feed for having a stable protein content, regardless of their diets. Therefore, T. molitor larvae have been produced industrially as feed for pets, zoo animals, and even for production animals. To maintain the nutrient composition and safety of T. molitor larvae, slaughtering (heating or freezing) and post-slaughtering (drying and grinding) procedures should be improved for animal feed. T. molitor larvae are also processed with defatting or hydrolysis before grinding. They have a high quality and quantity of protein and amino acid profile, so are considered a highly sustainable protein source for replacing soybean meal or fishmeal. T. molitor has a chitin in its cuticle, which is an indigestible fiber with positive effects on the immune system. In studies of poultry, the supplementation of T. molitor larvae improved the growth performance of broiler chickens, without having negative effects on carcass traits, whereas some studies have reported that there were no significant differences in the growth performance and carcass yield of broiler chickens. In studies of swine, the supplementation of T. molitor larvae improved the growth performance and protein utilization of weaning pigs. Furthermore, 10% of T. molitor larvae showed greater amino acid digestibility than conventional animal proteins in growing pigs. However, there are some challenges regarding the biosafety, consumer's acceptance, and price for the use of T. moiltor larvae in animal feed. Consequently, T. molitor larvae could be used as an alternative or sustainable protein source in monogastric animal feed with a consideration of the nutritional values, biosafety, consumer's acceptance, and market price of T. molitor larvae products.

Mealworm (Tenebrio molitor Larvae) as an Alternative Protein Source for Monogastric Animal: A Review

Edible insects have been considered as either nutritious food itemsper se, or as wholesome ingredients to various dishes and components of traditional subsistence. Protein, fat, mineral and vitamin contents in insects generally satisfy the requirements of healthy food, although there is considerable variation associated with insect species, collection site, processing method, insect life stage, rearing technology and insect feed. A comparison of available data(based on dry weight) showed that processing can improve the nutrient content, taste, flavour, appearance and palatability of insects, but that there are additional factors, which can impact the content and composition of insect species that have been recommended for consumption by humans. This review focuses on factors that have received little attention in connection with the task to improve acceptability or choice of edible insects and suggests ways to guarantee food security in countries where deficiencies in protein and minerals are an acute and perpetual problem. This review is meant to assist the food industry to select the most suitable species as well as processing methods for insect-based food products.

Chemical Composition, Nutrient Quality and Acceptability of Edible Insects Are Affected by Species, Developmental Stage, Gender, Diet, and Processing Method

Niche construction through interspecific interactions can condition future community states on past ones. However, the extent to which such history dependency can steer communities towards functionally different states remains a subject of active debate. Using bacterial communities collected from wild pitchers of the carnivorous pitcher plant, Sarracenia purpurea, we test the effects of history on composition and function across communities assembled in synthetic pitcher plant microcosms. We find that the diversity of assembled communities is determined by the diversity of the system at early, pre-assembly stages. Species composition is also contingent on early community states, not only because of differences in the species pool, but also because the same species have different dynamics in different community contexts. Importantly, compositional differences are proportional to differences in function, as profiles of resource use are strongly correlated with composition, despite convergence in respiration rates. Early differences in community structure can thus propagate to mature communities, conditioning their functional repertoire.

/pdf/context-dependent-dynamics-lead-to-the-assembly-of-4cdndbnhli.pdf

Context-dependent dynamics lead to the assembly of functionally distinct microbial communities.

Inhabitants of the Indonesian island of Sumatra are faced with the problem of insufficient food supplies and the consequent risk of undernourishment and health issues. Edible insects as a traditional and readily available food source could be part of the solution. The nutritional value of insects depends on many factors, e.g., species, developmental stage, sex, diet, and climatic conditions. However, edible insects bred in Sumatra for human consumption have never before been assessed with regard to their nutritional value. Our study involved analyses of crude protein, chitin, fat and selected fatty acid contents of giant mealworm larvae (Zophobas morio), larvae of the common mealworm (Tenebrio molitor) and nymphs of the field cricket (Gryllus assimilis). Crude protein content in the samples ranged from 46% to 56%. Highest (35%) and lowest (31%) amounts of fat were recorded in giant mealworm larvae and larvae of the common mealworm, respectively. Chitin amounts ranged from 6% to 13%. Based on these values, which are comparable to those known from other food insects reared in different regions of the world, the edible species bred in Sumatra could become food sources with a potential to help stave off hunger and undernourishment.

https://www.mdpi.com/1660-4601/14/5/521/pdf

Nutritional Potential of Selected Insect Species Reared on the Island of Sumatra

Many Indonesian birds are severely threatened or already at the brink of extinction due to the flourishing illicit bird trade. One such species is the Sumatran Laughingthrush Garrulax bicolor , endemic to Sumatra. From March 2015 to February 2016 we assessed the extent of trade of Sumatran Laughingthrushes by recording monthly turnovers from the six most prominent bird vendors in Medan’s Jalan Bintang market. In total, 2610 wild-caught individuals were traded, despite a considerable decline in market supply over the year. Total market mortality reached 16%. Mortality varied significantly during the year but was not dependent on the number of traded individuals each month. Monitoring revealed that the most frequently harvested localities were located in Aceh, North and West Sumatra and Riau province. Since the current estimate of the maximum population size of the species in the wild is 10,000 mature individuals, the level of trade is clearly unsustainable, and if not stopped, could lead to its extinction in near future.

Ongoing illicit trade of Sumatran Laughingthrush Garrulax bicolor : one-year market monitoring in Medan, North Sumatra

Decline of biodiversity, especially in tropical areas and rainforests, due to human activity is a serious global issue. Recovery programs, including reintroductions, are one means of active species protection and biodiversity preservation. The Sumatran Laughingthrush Garrulax bicolor (SL), a little known passerine endemic to Sumatra Island, is currently suffering from serious population decline due to the intensity of the illegal wildlife trade and habitat loss in the region. Most local subpopulations have been extirpated and those remaining have been reduced, thus, urgent need for conservation has arisen. In this study, we carried out the soft-release of rehabilitated SLs, originating from the wild and kept in captivity. We released four SL pairs (N=8 individuals) in total and, by using radio-telemetry (VHF; <2 g tail-mounted tags); we assessed their survival rate and movement patterns. During the post-release period only one bird was monitored for the full, predetermined criterion period of three weeks for survival rate and site fidelity assessment and one death was confirmed directly. Affinity to the release site, defined by a 2 km radius around the release aviary, was lower for females, which left the release site within the first week after release leaving their fates unknown, compared with males which remained at the release site for up to three times longer. Therefore, only the males' home range sizes were calculated. As a standardised measure, only the first six days following release were included and 6-day home ranges were estimated as follows: 35.18±8.5 ha (mean±SE) with range 17.25–50.95 ha (N=4 males). We did not find significant differences in the distances of males from the release aviary with increasing days following release. As far as we know, this is the first field study providing novel knowledge of the recovery ability of the Sumatran Laughingthrush and of its post-release behaviour, which are crucial for species protection management.

https://bioone.org/journals/ornithological-science/volume-17/issue-2/osj.17.135/An-Experimental-Release-of-Rehabilitated-Wild-Caught-Sumatran-Laughingthrush-Garrulax/10.2326/osj.17.135.pdf

An Experimental Release of Rehabilitated Wild-Caught Sumatran Laughingthrush Garrulax bicolor: Assessment of Post-Release Survival and Dispersal Via Radio-Telemetry, North Sumatra, Indonesia

Indonesia ranks second to Brazil in the number of globally threatened bird species. The Sumatran Laughingthrush Garrulax bicolor was formerly abundant but has suffered population declines due to trapping for the pet trade, and now considered endangered. Despite knowledge gained from in-situ and ex-situ captive rearing programs, little is known about the biology and ecology of the species. Our study sought to redress this by undertaking a field study of its home range size and behaviour. One group of five individuals was located in North Sumatra province and observed from strategically positioned hides over three weeks to estimate the size of its home range using Minimum Convex Polygons (MCP). In total, we collected 70 GPS points representing either sight or call records. The inhabited area covered 1.07 km 2 with the most remote edge points being 1.9 km apart. The group occasionally joined mixed species feeding flocks which included Chestnut-capped Laughingthrush Rhinocichla mitrata and Black Laughingthrush Melanocichla lugubris .

Preliminary observations of the home range size and behaviour of the Sumatran Laughingthrush Garrulax bicolor

Parents can enhance their fitness by favouring that sex whose reproductive value is expected to be highest. In species in which females are the larger sex with potentially greater fitness returns, one can assume that parents should bias their investment toward daughters to increase their daughters’ reproductive value (i.e. age-specific expectation of all present and future offspring) and, thereby, indirectly increase their own inclusive fitness. In the study reported here, we investigated sex allocation in Tengmalm’s Owl (Aegolius funereus), a bird species with a pronounced female-biased sexual size dimorphism in which females are larger than the males. Assuming that parental investment would have the greatest effect on the fitness of larger daughters, we hypothesized that daughters should be favoured in good conditions and sons in poor conditions. Our study was conducted in the Czech Republic over seven breeding seasons (2006–2012). In total, 205 nestlings from 52 nests were sexed. The mean nestling sex ratio, 48.5 ± 4.6% (± standard error), did not depart from parity, and we did not identify any variable to be related to it. However, we did find that at fledging (1) the body mass of female offspring was approximately 8% heavier than that of male offspring, and (2) surprisingly, the body mass of female offspring tended to increase with decreasing prey abundance in the autumn, i.e. prior to breeding. One possible explanation of this “carry-over effect” is that parents increased their investment toward daughters to maximize their daughters’ survival and reproductive value in a poor environment. This explanation could be supported by the sex-specific effect of the adult’s condition on reproductive success. Whereas the number of fledglings tended to increase with increasing age of the mother, it also increased with decreasing wing length of the father. These results indicate that in the Tengmalm’s Owl large body size may be mainly important for female reproduction, while male reproductive success is independent of body size or is even associated with small body size. To the best of our knowledge, our study is the first to have found such a positive, relatively long-lasting, sex-specific carry-over effect of pre-breeding prey abundance on the condition of female offspring in a bird of prey species.

Tomáš Bušina

Papers

Nutritional Potential of Selected Insect Species Reared on the Island of Sumatra

Ongoing illicit trade of Sumatran Laughingthrush Garrulax bicolor : one-year market monitoring in Medan, North Sumatra

An Experimental Release of Rehabilitated Wild-Caught Sumatran Laughingthrush Garrulax bicolor: Assessment of Post-Release Survival and Dispersal Via Radio-Telemetry, North Sumatra, Indonesia

Preliminary observations of the home range size and behaviour of the Sumatran Laughingthrush Garrulax bicolor

Low food abundance prior to breeding results in female-biased sex allocation in Tengmalm’s Owl (Aegolius funerus)