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Based on the background of the exacerbating food shortage in the world, it is particularly important to diversify food resources in every possible direction. Among the choices available, edible insects have become an important alternative source of animal food with their high nutritional and functional (pharmacological) values, partially replacing normally consumed animal and livestock protein food sources. The utilization of edible insects has been an ancient custom since the dawn of civilization, attributed to their rich nutrition, alternate protein source, medicinal values, and presence of diverse secondary metabolites and alkaloids. This review provides an introduction to three key aspects of edible insects as food: freshness, long-term preservation, and medicinal value. It also provides details on the food source and products of edible insect species, their detailed nutritional composition and medicinal values, and their potential in producing alternative protein sources. Additionally, the review also encompasses rearing and producing technologies, resource utilization, and industrial development in China. Simultaneously, the problems and challenges faced in the artificial rearing and production development of edible insects, the production advantages over traditional livestock, and the farming evaluation and prospects of edible insects, as well as the lack of specific legislation on edible insects in China, are discussed. This review will be helpful in scientific knowledge propagation regarding edible insects for the public, guiding consumers to establish a diverse perception of sustainable agriculture and food sources in the world that has, as yet, been thwarted by food insecurity. Moreover, though edible insects could potentially serve as part of a commercial and industrial agri-enterprise that could generate a huge income, artificial rearing technology and edible insect product manufacturing and processing have not received sufficient attention from the government on a policy level, thereby leaving an open space for extensive research on edible insects as an alternate food source as well as an examination of the industrial prospects of edible insect products. [ABSTRACT FROM AUTHOR]

Elevated CO2 (eCO2) can affect the environmental adaptability of herbivorous insects by affecting the quality and quantity of host plants' nutrients under climate change. In this study, the impacts of eCO2 on carbohydrate metabolism, chitin synthesis and cuticle thickness of western flower thrips (Frankliniella occidentalis) fed on kidney bean (Phaseolus vulgaris) leaves were studied to elucidate the physiological responses of F. occidentalis to eCO2 and provide a theoretical basis for the occurrence trend of thrips under future climate change. The results indicated that the trehalose and glycogen contents in F. occidentalis adults significantly increased with corresponding regulation of key genes related to carbohydrate metabolism under eCO2 compared to ambient CO2 (aCO2), which was closely related to the increased foliar contents of starch and soluble sugars in P. vulgaris grown under eCO2. Subsequently, since trehalose is a precursor of chitin, changes in its content would further affect the chitin synthesis. With the up-regulation of genes related to chitin synthesis and the down-regulation of most genes related to chitin hydrolysis, the chitin content in F. occidentalis adults significantly increased resulting in their increased cuticle thickness and layers, which might enhance their resistance under eCO2 and become "thick-skinned thrips" under climate change condition. [ABSTRACT FROM AUTHOR]

Transgenic Bt rice (abbr. Bt rice) has provided a powerful tactics to control the striped stemborer Chilo suppressalis as one key lepidopteran pest in the paddyfields of China. Globally rising carbon dioxide (i.e., CO2) concentration has been predicted to affect the Cry protein contents in plant tissues of Bt rice and thus might affect its control efficiency to target insect pests. To reveal the resistance ability and the corresponding mechanism of C. suppressalis to Bt rice during different growth stage under elevated CO2 (eCO2), we carried out this experiment to measure the Bt toxin contents in Bt rice stems grown under ambient CO2 (aCO2) (400 ppm) and eCO2 (800 ppm) at seedling, tillering and heading stages, and to observe the larval mortality and bioassay the activity of midgut protease and the expression levels of Bt-toxin-receptor genes, aminopeptidases (APNs) in C. suppressalis larvae. Compared with aCO2, eCO2 increased the Bt-toxin content of Bt rice at seedling stage (+6.66%), and decreased that at heading stages (−13.99%), and significantly reduced the Bt-toxin content at tillering stage (−15.21%). And the larval mortality of C. suppressalis was lower as reared with Bt rice stems during tillering stage grown under eCO2 in contrast to aCO2. In addition, eCO2 significantly increased the activity of total protease, tryptase-like enzyme and aminopeptidase of C. suppressalis larvae fed on Bt rice during seedling stage, and significantly reduced the activity of tryptase-like enzyme and aminopeptidase of C. suppressails larvae fed on Bt rice during tillering and heading stages respectively. Moreover, eCO2 significantly increased the expression level of APN1 and APN5 of C. suppressails larvae fed on Bt rice during seedling stage, and significantly reduced the expression level of APN5 of C. suppressalis larvae fed on Bt rice during tillering and heading stages respectively. In summary, the control efficiency of Bt rice to target insect pests under eCO2 showed a downward trend during tillering and heading stages, and especially during tillering stage. [ABSTRACT FROM AUTHOR]

β‐Glucosidase is validated as an elicitor for early immune responses in plants and it was detected in the salivary glands of Frankliniella occidentalis in previous research. Seven differentially expressed genes encoding β‐glucosidase were obtained by comparing the transcriptomes of F. occidentalis adults grown under two different CO2 concentrations (800 vs. 400 ppm), which might be associated with the differences in the interaction between F. occidentalis adults and its host plant, Phaseolus vulgaris under different CO2 levels. To verify this speculation, changes in defense responses based on the production and elimination of reactive oxygen species (ROS) in P. vulgaris leaves treated with three levels of β‐glucosidase activity under ambient CO2 (aCO2) and elevated CO2 (eCO2) were measured in this study. According to the results, significantly higher levels of ROS were noticed under eCO2 compared to aCO2, which was caused by the increased β‐glucosidase activity in thrips due to increased cellulose content in P. vulgaris leaves under eCO2. Together with the lower activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in injured leaves under eCO2, P. vulgaris leaves would be negatively affected on redox‐based defense by eCO2, thus facilitating thrips damage under climate change. Summary Statement: β‐Glucosidase secreted by the Frankliniella occidentalis adults could induce early immune responses in the leaves of their host plant, Phaseolus vulgaris based on reactive oxygen species (ROS) and antioxidant enzymes, which was significantly affected by CO2 level. The higher β‐glucosidase activity of F. occidentalis adults under elevated CO2 (eCO2), which was probably caused by the increased cellulose content in P. vulgaris leaves, would lead to increased ROS levels in P. vulgaris leaves infested with thrips under eCO2, and the activities of antioxidant enzymes for scavenging ROS damage would be correspondingly increased but their overall levels were still lower than that under ambient CO2, which was beneficial to the feeding damage of thrips [ABSTRACT FROM AUTHOR]