Abstract: Hematophagous insects are arthropods that can spread insect-borne pathogens, including mosquitoes, sandflies, midges, kissing bugs, fleas and so on. Blood-feeding behavior makes them become the vectors transmitting malaria, dengue fever, filariasis, trypanosomiasis, and other acute infectious diseases. The fast and wide-spreading of vector-borne diseases, in addition to heavy damage to human health, might result in huge economic losses. Due to the scarcity of effective medicines and increasing drug resistance of pathogens, the interruption of reproduction of hematophagous insects is an effective measure to control the spread of insect-borne diseases. Juvenile hormone (JH) and 20-hydroxyecdysone (20E) play important roles in insect reproduction. JH binds to intracellular receptor complex Met/Tai to regulate the expression of JH/Met target genes, and then promotes vitellogenesis, which provides pre-requisite to bloodfeeding and oviposition of insects. Heterodimer EcR/USP is an intracellular receptor of 20E. The combination of 20E with EcR/USP complex can activate downstream gene expression and induce the synthesis of vitellogenin (Vg) to provide nutrition for the developing ovary. Nutrient signaling pathways (insulin signaling pathway and amino acidmediated target of rapamycin signaling pathway) can also activate Vg synthesis and promote insect reproduction. In addition, nutrient signaling pathways can interplay with JH and 20E signaling cascades to regulate the development and reproduction of hematophagous insects. Energy metabolism, such as carbohydrate and lipid metabolism, is the main energy source during insect reproduction, which can meet the extremely high energy requirements in different stages of reproductive development of hematophagous insects. Studies have shown that JH and 20E signaling pathways play important regulatory roles in energy metabolism. MicroRNAs have been proved to be closely related to physiological processes such as gut microbiome homeostasis, blood digestion and lipid metabolism in mosquitoes, further affecting the development mosquitoes. In recent years, with the innovation of molecular biology and sequencing technology, new progress has been made in the study of reproductive regulation mechanisms in hematophagous insects. In this article, we present the research progress and insights into molecular mechanisms of reproductive regulation in hematophagous insects, which will provide important clues for blocking the transmission of vector-borne diseases by regulating the reproduction of hematophagous insects.

Key words: Hematophagous insects, pathogenic microorganism, vectors, vector-borne diseases, reproductive regulation