The white wax secreted by the male insects of the Chinese white wax scale (CWWS) is a natural high-molecular-weight compound with important economic value. However, its regulatory mechanism of wax biosynthesis is still unclear. In this study, a weighted gene coexpression network analysis (WGCNA) was used to analyze transcriptome data of first- and second-instar females, early and late female adults, and first- and second-instar males. A total of 19 partitioned modules with different topological overlaps were obtained, and three modules were identified as highly significant for wax secretion (p < 0.05). A total of 30 hub genes were obtained through screening, among which elongation of very-long-chain fatty acids protein (ELOVL) and fatty acyl-CoA reductase (FAR) are important catalytic enzymes of fatty acid metabolism. Furthermore, their metabolic catalytic products are involved in the synthesis of wax biosynthesis. The results demonstrate that WGCNA can be used for insect transcriptome analysis and effectively screen out the key genes related to wax biosynthesis. Full article

Background: Whole-genome sequencing has become routine for population genetic studies. Sequencing of individuals provides maximal data but is rather expensive and fewer samples can be studied. In contrast, sequencing a pool of samples (pool-seq) can provide sufficient data, while presenting less of an economic challenge. Few studies have compared the two approaches to infer population genetic structure and diversity in real datasets. Here, we apply individual sequencing (ind-seq) and pool-seq to the study of Western honey bees (Apis mellifera). Methods: We collected honey bee workers that belonged to 14 populations, including 13 subspecies, totaling 1347 colonies, who were individually (139 individuals) and pool-sequenced (14 pools). We compared allele frequencies, genetic diversity estimates, and population structure as inferred by the two approaches. Results: Pool-seq and ind-seq revealed near identical population structure and genetic diversities, albeit at different costs. While pool-seq provides genome-wide polymorphism data at considerably lower costs, ind-seq can provide additional information, including the identification of population substructures, hybridization, or individual outliers. Conclusions: If costs are not the limiting factor, we recommend using ind-seq, as population genetic structure can be inferred similarly well, with the advantage gained from individual genetic information. Not least, it also significantly reduces the effort required for the collection of numerous samples and their further processing in the laboratory. Full article

Considering food safety and an increasing public awareness of the ingredients, production process and origin of foods, the application of insects as food requires the development of tests for the reliable identification of their presence. The aim of the study was (1) the determination of appropriate modifications of the selected method for isolating the DNA of two life stages of mealworm, i.e., larva and adult, from commercial food products; (2) the determination of the method parameters for the qualitative and quantitative analysis of mealworm contents based on the detection of a species-specific mitochondrial DNA fragment, using real-time PCR; (3) the application of a method to test the commercial food products of mealworm. A total of nine species of adult insect were investigated (field cricket, Dubia cockroach, Madagascar cockroach, banded cricket, migratory locust, yellow mealworm, superworm, house fly and lacewing), theirlarvaes (yellow mealworms and superworms) and thirteen commercial food products (dried whole insects, powder and granules) representing various insect species and origins which were purchased from the European market. The obtained results showed that the efficiency of the modification of the DNA extraction method is dependent on the life stage of the mealworm. We proved the high sensitivity of the test, with the range of the method being 0.1–100%; we also proved the biological specificity in this range, and the linearity. The linearity of the test was also statistically verified using the Fisher–Snedecor test. One-way variance analysis showed statistically significant differences between the c_T values of the two mealworm life stages studied, and similarly, between the threshold cycle (c_T) values of adult forms. In contrast, for the inside group of mealworm larvae, there was no significant difference observed between the results of the c_T values. The test is effective for processed food products and may be used to monitor food. The research proved the suitability of the applied method for the analysis of samples that are commercially available as food for exotic animals. The hereby-developed method is based on widely used laboratory techniques, and does not require any additional investment in equipment. The availabilityof such a methodallows for the verification of the accuracy of the declared species component of the food products. Full article