*3.1.1 Development and metabolism*

The specific expression of the miRNA stage in the four stages of development (eggs, larvae, pupae, and adults) was confirmed using sequencing. Understand the role of regulated miRNAs in the development of the mosquito and the action of knocking down the expressed miRNAs in a specific way carried out in *Ae. albopictus*. The knockdown of aal-miR-286b and aal-miR-2942 decreased the hatching of embryos and the hatching rate of larvae, respectively, compared to the knock-in groups. Reduced longevity and fertility (aal-miR-1891) were observed in the knockdown groups for miR-1891 compared to the knock-in and control groups in adults. Female mosquitoes require sugar for energy metabolism and a blood meal for egg development. Recent studies have indicated that blood supply leads to the differential expression of many genes, proteins, and miRNAs. The abundance of miRNA differs under sugar-fed and blood-fed conditions; ast-miR-2796-5p was observed exclusively in sugar-fed. The depletion of aae-miR-275 in *Ae. aegypti* females led to severe defects in blood digestion, fluid excretion, and egg development. aaemiR-1890 is induced after blood feeding and reaches a peak of 24 PMB. The systemic depletion of aae-miR-1890 resulted in less egg development and deposition, suggesting that miR-1890 may be the key to mosquito blood digestion. In contrast to the upregulated miRNAs after blood feeding, some miRNAs were downregulated. For example, reduced ast-miR-989 was observed 72 h after a blood meal. aga-let7 decreased in the midgut and other parts/leftovers, but most miRNAs increased after blood feeding [35–37].
