Dynamic surveillance of mosquitoes and their viromes in Wuhan during 2020

Mosquitoes are medically important arthropod vectors and harbor a great variety of viruses. The population density, species and virome of mosquitoes varies according to geography and climate. To investigate the dynamic changes in the species composition and diversity of mosquitoes and their viromes in Wuhan, China, a total of 2,345 adult mosquitoes collected from different habitats including an urban residential area, two hospitals, a scenic area, and a pig farm in a rural region from April to October 2020 were subjected to morphological identification, RT-qPCR and metagenomic sequencing. The results indicated that the dominant presence of Culex mosquitoes was observed in both urban regions (90.32%, 1538/1703) and the pig farm (54.98%, 353/642). Viromes of Culex showed dynamic changes during the collection time. Several viruses, such as Culex flavivirus, Alphamesonivirus 1, Hubei mosquito virus 2 and Hubei mosquito virus 4, had seasonal changes and unimodal increases or declines. Other viruses, such as Wuhan mosquito virus 6, Hubei virga-like virus 2 and Zhejiang mosquito virus 3, were stable in all collected Culex and should be potential members of "core viromes". This study improves the understanding of the dynamic composition of mosquitoes and the viromes they carry and provides useful information for informing mosquito control and mosquito-borne disease prevention strategies.