Edible insects in China: Utilization and prospects

The use of edible insects has a long history in China, where they have been consumed for more than 2000 years. In general, the level of acceptance is high for the consumption of insects in China. Many studies on edible insects have been conducted in the last 20 years, and the scope of the research includes the culture of entomophagy and the identification, nutritional value, farming and breeding of edible insects, in addition to food production and safety. Currently, 324 species of insects from 11 orders are documented that are either edible or associated with entomophagy in China, which include the common edible species, some less commonly consumed species and some medicinal insects. However, only approximately 10 to 20 types of insects are regularly consumed. The nutritional values for 174 species are available in China, including edible, feed and medicinal species. Although the nutritional values vary among species, all the insects examined contain protein, fat, vitamins and minerals at levels that meet human nutritional requirements. Edible insects were, and continue to be, consumed by different ethnic groups in many parts of China. People directly consume insects or food products made from insects. The processing of products from insect protein powder, oil and chitin, and the development of healthcare foods has been studied in China. People also consume insects indirectly by eating livestock that were fed insects, which may be a more acceptable pathway to use insects in human diets. Although limited, the data on the food safety of insects indicate that insects are safe for food or feed. Incidences of allergic reactions after consuming silkworm pupae, cicadas and crickets have been reported in China. Insect farming is a unique breeding industry in rural China and is a source of income for local people. Insects are reared and bred for human food, medicine and animal feed using two approaches in China: the insects are either fully domesticated and reared completely in captivity or are partially raised in captivity, and the insect habitat is manipulated to increase production. Depending on the type of relationship the insect has with humans, plants and the environment, different farming strategies are used. The social and scientific communities must work together to promote the use of insects as food and feed.     

Feasting on insects

Insects are an important natural resource, both for self-sufficiency and as commercial food products in many parts of the world. The use of edible insects reflects regional preferences and socio-cultural significance, which can be described in terms of regional differences. This study describes some edible insects in three regions: Japan, Southeast Asia and Southern Africa, and focuses on systems of traditional practices as the socio-cultural implications of people's preferences regarding edible insects. The case studies presented here describe such insect-related customs as the continuation of the traditional practice of insect eating in Japan, Southeast Asia and Southern Africa. These case studies describe the uniqueness or special characteristics of the custom, and the significance of its existence in the social sphere. Edible insects are regarded as cultural resources reflecting a rich biodiversity. They represent an alternative source of natural food resources in remote or mountainous areas. People who eat insects have established a broad variety of methods for collecting and cooking the rich diversity of edible insect species that are available. However, increases in demand could lead to competition and overexploitation, resulting in the future decline of these resources. In areas affected by overdevelopment, insect habitats are also likely to decline. It is necessary to raise people's awareness of the importance of the use of insects for food in order to ensure that insects are used in a sustainable manner, and to promote their proper use and conservation.     

Ecological diversity of edible insects and their potential contribution to household food security in Haut‐Katanga Province,Democratic Republic of Congo

Democratic Republic of the Congo (DR Congo) has a wide diversity of edible insects making it one of the most important biodiversity hot spots in Africa. The aim of this study was to give the first insight into the food plant range, seasonal availability of edible insects, community preference and willingness to consume them. The study revealed a list of eleven edible insect species belonging to four families. Twenty‐six plant species were recorded as food plants of nine edible caterpillar species. Seasonal availability of these insects coincided with the rainy season and was strongly linked to relatively high level of consumption. The caterpillars Elaphrodes lactea Gaede, Lobobunaea saturnus Fabricius and Cinabra hyperbius (Westwood) as well as the termites Macrotermes falciger Gerstäcker were the most dominant species of edible insects preferred and consumed among the different communities. Our study demonstrates that entomophagy is a common practice among the ethnic populations with married, tertiary and university‐level individuals recording significantly higher consumption of edible caterpillars. Populations between the ages of 18 and 45 years as well as the Bemba tribe were also more actively involved in entomophagy. Further research would be necessary to exploit edible insect biodiversity and ethno‐entomophagy and initiate actions for food plant conservation in DR Congo.     

KNApSAcK family databases: integrated metabolite-plant species databases for multifaceted plant research

A database (DB) describing the relationships between species and their metabolites would be useful for metabolomics research, because it targets systematic analysis of enormous numbers of organic compounds with known or unknown structures in metabolomics. We constructed an extensive species-metabolite DB for plants, the KNApSAcK Core DB, which contains 101,500 species-metabolite relationships encompassing 20,741 species and 50,048 metabolites. We also developed a search engine within the KNApSAcK Core DB for use in metabolomics research, making it possible to search for metabolites based on an accurate mass, molecular formula, metabolite name or mass spectra in several ionization modes. We also have developed databases for retrieving metabolites related to plants used for a range of purposes. In our multifaceted plant usage DB, medicinal/edible plants are related to the geographic zones (GZs) where the plants are used, their biological activities, and formulae of Japanese and Indonesian traditional medicines (Kampo and Jamu, respectively). These data are connected to the species-metabolites relationship DB within the KNApSAcK Core DB, keyed via the species names. All databases can be accessed via the website http://kanaya.naist.jp/KNApSAcK_Family/. KNApSAcK WorldMap DB comprises 41,548 GZ-plant pair entries, including 222 GZs and 15,240 medicinal/edible plants. The KAMPO DB consists of 336 formulae encompassing 278 medicinal plants; the JAMU DB consists of 5,310 formulae encompassing 550 medicinal plants. The Biological Activity DB consists of 2,418 biological activities and 33,706 pairwise relationships between medicinal plants and their biological activities. Current statistics of the binary relationships between individual databases were characterized by the degree distribution analysis, leading to a prediction of at least 1,060,000 metabolites within all plants. In the future, the study of metabolomics will need to take this huge number of metabolites into consideration.     

Developmental database for phenology models: related insect and mite species have similar thermal requirements

Two values of thermal requirements, the lower developmental threshold (LDT), that is, the temperature at which development ceases, and the sum of effective temperatures, that is, day degrees above the LDT control the development of ectotherms and are used in phenology models to predict time at which the development of individual stages of a species will be completed. To assist in the rapid development of phenology models, we merged a previously published database of thermal requirements for insects, gathered by online search in CAB Abstracts, with independently collected data for insects and mites from original studies. The merged database comprises developmental times at various constant temperatures on 1,054 insect and mite species, many of them in several populations, mostly pests and their natural enemies, from all over the world. We show that closely related species share similar thermal requirements and therefore, for a species with unknown thermal requirements, the value of LDT and sum of effective temperatures of its most related species from the database can be used.     

Anthropo-entomophagy: Cultures, evolution and sustainability

Environmental cycles and human factors have altered ecosystems throughout the world. Natural resources have acquired high value because they are important to life and the survival of human beings. Among these resources are edible insects. They have many important features and, to date, up to 2086 species are consumed by 3071 ethnic groups. Rural people, who primarily search, gather, fix, commercialize and store this important natural resource, do not exterminate them. This is because rural people exploit only the central part of the insects' population curves. Nonetheless, some species are overexploited. Anthropo-entomophagy (eating of insects by humans) constitutes a major source of nutrition and these foods are eaten in 130 countries, with the African and American continents being the most entomophagous until now. It exists in protocultures (care is given to the edible insect species) and formal cultures, such as in Mexico, which date back to prehisphanic times. According to anthropologists the "saving gene theory" is based on insect ingestion, which, since the Paleolithic era, has given human beings reproductive success. The evolution of anthropo-entomophagy has been achieved in many ways, from the point of view of collection, fixing, marketing and consumption, and for the insects' organoleptical qualities. The sustainability of these species is fundamental; therefore, it is necessary to take certain measures for species conservation. In Mexico, more than 100 species of edible insects have been tested for their sustainability over 500 years, from the Spanish conquest to the present.     

Common edible insects and their utilization in China

This paper reviews the common edible insects and their use in China. One-hundred and seventy-eight insect species from 96 genera, 53 families and 11 orders are commonly eaten in China. Preparation of edible insects includes frying, braising, stewing, stewing after frying, boiling and roasting. The insect forms eaten range from eggs to adults; however, in restaurants most are larvae and pupae. More than 50 species have been analyzed for their nutritive elements and nutritional value and these data are reviewed here. Insect health foods sold in the Chinese market are also briefly discussed.     

Changes of amino acid composition and protein technical functionality of edible insects by extracting steps

Interest in edible insects is increasing with increase population and food demand, and research on their applications is underway. Quality changes of protein during extraction from edible insects are crucial for food application. Therefore, we investigated the amino acid composition and protein technical functionality extracted from three different edible insects (Tenebrio molitor, Allomyrina dichotoma, Protaetia brevitarsis). Three steps used for protein extraction were: grounding, de-fatting, and extraction. Essential amino acid index was increased undergone protein extraction steps. Allomyrina dichotoma had the best value at all steps and Protaetia brevitarsis was followed. The pH values of the extract increased with each step except for Tenebrio molitor. Further, lightness, redness, and yellowness decreased generally. Protein molecular weight differed according to species and Protaetia brevitarsis had the widest protein bands after extracting. Through extraction steps, foam capacity and stability were improved and emulsion capacity and stability did not improve dramatically. In conclusion, Protaetia brevitarsis was the most suitable edible insect to use for protein sources and protein extraction can be useful way to improve protein technical functionality of edible insects.     

湖北省中药材贮藏期昆虫名录

本文对1991年在湖北省17年市县的中药材贮藏期昆虫进行了调查,共鉴定也123种昆虫螨,隶属于2纲10目49科。其中害虫96种,天敌27种。国内新纪录8种（右上角标记**）,湖北省新纪录17种（右上角标记*）。并对123种昆虫的分布及寄主分别进行了记述。     

昆虫种群动态模拟模型

昆虫是动物界中最大的类群,与人类有着密切的利害关系。对昆虫的数量预测与符合经济和生态规律的管理,一直都被国内外列入重点研究课题。种群动态模拟是害虫管理中重要的基础工作。近十年来,关于昆虫种群动态模型的理论和实验研究进展迅速。现分别从单种种群和多种种群两个方面对国内外近些年来昆虫种群动态模拟模型的研究进展进行了概括和总结。单种种群从两个方面阐述:一是最基本的种群动态模拟模型Log istic方程的研究成果,包括方程的修正、参数的拟合与最优捕获策略等;另一个方面是对种群动态模拟常用的矩阵模型的概述,主要介绍不等期年龄组、矩阵维数的变化、矩阵维数与历期的关系、个体之间的发育差异以及发育速率差异等等对昆虫种群动态模型的影响。多种群主要从建模和模型应用两个部分对国内外研究成果进行综述。最后,对种群动态模拟模型研究的发展方向做了深入地讨论,即在原有的数据采集工作的基础上,使用面向对象程序设计语言,把各种要素包括各种物种及各种环境条件抽象成类,用消息传递来表示昆虫种群内个体与个体、昆虫种群与环境之间的相互作用,再结合先进的数学算法,建立一个直观的、操作简单的昆虫种群动态模型库,使模型结构与现实世界有最大的相似性。这样就可以实现昆虫种群动态的可视化、立体化、实时化和精确化的监测及预测。     

基于MFCC和GMM的昆虫声音自动识别

昆虫的运动、 取食、 鸣叫都会发出声音, 这些声音存在种内相似性和种间差异性, 因此可用来识别昆虫的种类。基于昆虫声音的昆虫种类自动检测技术对协助农业和林业从业人员方便地识别昆虫种类非常有意义。本研究采用了语音识别领域里的声音参数化技术来实现昆虫的声音自动鉴别。声音样本经预处理后, 提取梅尔倒谱系数（Mel frequency cepstrum coefficient, MFCC）作为特征, 并用这些样本提取的MFCC特征集训练混合高斯模型（Gaussian mixture model, GMM）。最后用训练所得到的GMM对未知类别的昆虫声音样本进行分类。该方法在包含58种昆虫声音的样本库中进行了评估, 取得了较高的识别正确率（平均精度为98.95%）和较理想的时间性能。该测试结果证明了基于MFCC和GMM的语音参数化技术可以用来有效地识别昆虫种类。     

CIBMAN: Database exploring Citrus biodiversity of Manipur

The rich wealth of Citrus genetic resources makes India to enjoy a remarkable position in the “Citrus belt of the world”. We have developed CIBMAN, a unique database on Citrus biodiversity of Manipur which comprises 33 accessions collected through extensive survey for more than three years. CIBMAN provides integrated access to Citrus species through sophisticated web interface which has following capabilities a) morphological details, b) socio-economic details, c) taxonomic details and d) geographical distribution. Morphological variability among Citrus accessions is due to variance in their genome which contributes to diverse agronomical traits and diverse bioactive compounds of high value. This diverse gene pool can be potential source for genetic improvement of existing cultivars and rootstocks. Systematic collection, characterization and conservation of the underutilized or lesser exploited varieties is required for incorporating in breeding program and conserve the germplasm from ever going on genetic erosion. This database will be useful for scientific validations and updating of traditional wisdom in bioprospecting aspects especially industrialization of Citrus found in the state. Further, the features will be suited for detailed investigation on potential medicinal and edible Citrus that make CIBMAN a powerful tool for sustainable management.

Availability

http://ibsd.gov.in/cibman     

Host insect species of Ophiocordyceps sinensis: a review

Ophiocordyceps sinensis (≡ Cordyceps sinensis) is one of the most valued medicinal fungi in China, used for its invigorating effects in strengthening the body and restoring energy. The fungus parasitizes larvae of moths and converts them into sclerotia from which the fungus fruiting body grows. Since the late 1950s, considerable effort has been devoted to the study of host insects related to the fungus. In the present paper, the research history of insect species associated with Ophiocordyceps sinensis is briefly reviewed and an extensive literature survey is presented. Ninety-one insect names, spanning 13 genera, related to host insects of Ophiocordyceps sinensis are investigated. The relationships between the reported insect species and Ophiocordyceps sinensis are analyzed. Fifty-seven of these are considered as recognizable potential host species of the fungus distributed throughout the Tibetan Plateau, whilst eight are considered as indeterminate hosts and 26 as non-hosts. Among the names of recognizable potential host insects, three are invalid (nomen nudum) and require further study. This work provides basic information for management of the insect resources and for the conservation and sustainable use of Ophiocordyceps sinensis.     

滇川桂3省暗褐网柄牛肝菌菌腔虫瘿的寄主植物与介壳虫种类调查

暗褐网柄牛肝菌Phlebopus portentosus与介壳虫形成的菌腔虫瘿是该菌营养机制研究的关键环节。本研究先后在云南、四川和广西3省区暗褐网柄牛肝菌产区的16个地点,对菌腔虫瘿的生态和生物学进行了大量的野外调查。发现根部着生菌腔虫瘿的寄主植物有31种,涉及16个科的28个属。与暗褐网柄牛肝菌形成菌腔虫瘿的介壳虫种类有12种,其中10种隶属粉蚧科Pseudococcidae、绵蚧科Monophlebidae、蚧科Coccidae各1种。在不同的寄主植物上菌腔虫瘿的寄生位置和形状会有所不同,与暗褐网柄牛肝菌菌丝形成菌腔虫瘿的寄主植物和介壳虫之间不存在专一性。上述研究结果为暗褐网柄牛肝菌的仿生栽培奠定了基础。     

Species diversity of insects in Japan: Their origins and diversification processes

Japan is considered a global hot spot of biodiversity. With regard to species diversity, insects are no exception. To date, more than 32,000 insect species have been identified in Japan, while around 100,000 species of insects are estimated to inhabit this country. In this paper, we outline background factors having contributed to diversification of Japanese insects. Of course, the high degree of Japanese insect diversity is the result of many complex factors. In addition to the humid Asian monsoon climate and the extensive latitudinal gradient of habitats, the extremely complex geological history has contributed as an important factor to generate and maintain the high species diversity and endemism. In particular, the independent origins of northeastern and southwestern Japan from the Eurasian continent have greatly contributed to the diverse composition of Japanese insect fauna. To highlight the importance of this process, we introduce some case studies and previously published papers focusing on several insect groups with low dispersal ability. Those cases indicate that the geological history of Japan has played an important role in the differentiation of Japanese insect species. Besides such geological factors, climatic and ecological factors in combination have contributed to the formation of Japanese insect fauna in complicated ways and produced its particularly high degree of biodiversity. The knowledge compiled here will provide useful information for future studies aiming to understand more deeply the processes of speciation and faunal formation of Japanese insects.     

Age and size at maturity: A quantitative review of diet‐induced reaction norms in insects

Optimality models predict that diet‐induced bivariate reaction norms for age and size at maturity can have diverse shapes, with the slope varying from negative to positive. To evaluate these predictions, we perform a quantitative review of relevant data, using a literature‐derived database of body sizes and development times for over 200 insect species. We show that bivariate reaction norms with a negative slope prevail in nearly all taxonomic and ecological categories of insects as well as in some other ectotherm taxa with comparable life histories (arachnids and amphibians). In insects, positive slopes are largely limited to species, which feed on discrete resource items, parasitoids in particular. By contrast, with virtually no meaningful exceptions, herbivorous and predatory insects display reaction norms with a negative slope. This is consistent with the idea that predictable resource depletion, a scenario selecting for positively sloped reaction norms, is not frequent for these insects. Another source of such selection—a positive correlation between resource levels and juvenile mortality rates—should similarly be rare among insects. Positive slopes can also be predicted by models which integrate life‐history evolution and population dynamics. As bottom‐up regulation is not common in most insect groups, such models may not be most appropriate for insects.     

The composite insect trap: an innovative combination trap for biologically diverse sampling

Documentation of insect diversity is an important component of the study of biodiversity, community dynamics, and global change. Accurate identification of insects usually requires catching individuals for close inspection. However, because insects are so diverse, most trapping methods are specifically tailored to a particular taxonomic group. For scientists interested in the broadest possible spectrum of insect taxa, whether for long term monitoring of an ecosystem or for a species inventory, the use of several different trapping methods is usually necessary. We describe a novel composite method for capturing a diverse spectrum of insect taxa. The Composite Insect Trap incorporates elements from four different existing trapping methods: the cone trap, malaise trap, pan trap, and flight intercept trap. It is affordable, resistant, easy to assemble and disassemble, and collects a wide variety of insect taxa. Here we describe the design, construction, and effectiveness of the Composite Insect Trap tested during a study of insect diversity. The trap catches a broad array of insects and can eliminate the need to use multiple trap types in biodiversity studies. We propose that the Composite Insect Trap is a useful addition to the trapping methods currently available to ecologists and will be extremely effective for monitoring community level dynamics, biodiversity assessment, and conservation and restoration work. In addition, the Composite Insect Trap will be of use to other insect specialists, such as taxonomists, that are interested in describing the insect taxa in a given area.     

五种鳞翅目害虫中抗药性相关基因的转录组学分析

随着测序技术的发展,昆虫转录组数据不断积累,在昆虫学研究中的应用也越来越广泛。在害虫抗药性的研究中,转录组数据分析也是重要的最新研究手段。本文通过对5种鳞翅目害虫转录组的生物信息学分析,鉴定出13种与抗药性相关的基因,发现细胞色素P450基因序列数量最多,共887条。另外,谷胱甘肽S-转移酶、鱼尼丁受体、氨肽酶N、糖基转移酶相关的基因序列多于100条。同时,对这5种鳞翅目昆虫中部分Bt受体相关的基因做了多序列比对和进化分析。分析认为,从多物种、多基因的角度提出对农药抗性的系统性研究,是害虫抗性研究的发展趋势。     

Note on using nuclear 28S rDNA for sequencing ancient and strongly degraded insect DNA

A protocol using insect specimens or parts thereof allows for sequencing of sections of nuclear 28S rDNA. In the present note it is demonstrated that this protocol can readily be applied to strongly degraded DNA (ancient, fixed or contaminated). Primers that are specifically designed to discriminate against human DNA but also other non‐arthropod species are tested on a range of species covering all insect groups (59 insect species from all 33 orders). Additionally, the samples represent a selection of various, mostly DNA‐degrading, preservation methods, including the most common fixatives used for morphological investigations and for long‐term storage in collections. Successful amplification was possible for all tested samples including ca. 200 year‐old dried museum specimens as well as for over 4000 year‐old fossil insects embedded in copal. When the NCBI database contained information on the tested species an unambiguous taxonomic discrimination was possible. This approach is based on a standardized protocol that guarantees easy application. This note presents primer pairs for 28S rDNA that can be a useful tool for ancient DNA (aDNA) research.