The Chinese white wax scale insect, Ericerus pela Chavannes (Hemiptera: Coccidae), is one of the scale insects with great economic value and has been dispersed and reared in China for over one thousand years. Its mitochondrial genome provides essential information for the molecular identification and genetic study of this species. We assembled the complete mitochondrial genome of E. pela based on PacBio sequencing and analyzed its genomic features. The genome was 17,766 bp in length with 13 protein-coding genes, 22 tRNAs, and two rRNA genes. The analysis results showed E. pela had significant gene rearrangements involving tRNAs compared with other Coccoidea species. Furthermore, E. pela’s nine tRNAs were identified to have obvious truncated structures. The phylogenetic tree compiled of the species showed a long branch of the Coccoidea lineage, which indicated the high evolutionary rate in this group. Our study revealed the mitochondrial characteristics of E. pela and enriched the mitochondrial genetic information on Coccoidea species. It also determined the occurrence of gene rearrangement for the species in this superfamily.

Fenugreek (Trigonella foenum-graecum L.) is a traditional medicinal plant for treating human diseases that is widely cultivated in many countries. However, the component and related metabolic pathways are still unclear. To understand the changes in expression of the component and related genes during seed development, this study employed metabolomic and transcriptomic analyses and integrative analysis to explore the metabolites and pathways involved in the growth of fenugreek. The antifungal activity of the fenugreek seeds was also analyzed. A total of 9499 metabolites were identified in the positive ion mode, and 8043 metabolites were identified in the negative ion mode. Among them, the main components were fatty acyls, prenol lipids, steroids, steroid derivatives, flavonoids, and isoflavonoids. Among these enriched pathways, the top 20 pathways were “flavone and flavonol biosynthesis”, “isoflavonoid biosynthesis”, and “flavonoid biosynthesis”. 3,7-Di-O-methylquercetin, flavonoids, pseudobaptigenin, isoflavonoids, methylecgonine, alkaloids, and derivatives were the most significantly upregulated metabolites. There were 38,137 differentially expressed genes (DEGs) identified via transcriptomic analysis. According to the KEGG pathway enrichment analysis, 147 DEGs were significantly enriched in “flavonoid biosynthesis”. Ten DEGs of the six key enzymes were found to be involved in three pathways related to flavonoid and alkaloid synthesis in fenugreek. The antifungal activity test revealed the inhibitory effect of the ethanol extract of fenugreek seeds on Alternaria tenuissima (Kunze)Wiltshire and Magnaporthe oryzae. These findings further prove that the use of botanical pesticides in fenugreek fruit has research value.