D3333: Assessing the susceptibility of Culex pipiens (Culicidae) mosquitoes to insect-specific virus infections

Culex pipiens mosquitoes are one of the major vectors of West Nile virus (WNV) in North America. Their generalist feeding behaviour allows them to serve as a bridge vector and transmit WNV from birds to humans. Aside from medically important mosquito-borne pathogens, newly discovered viruses that only infect mosquitoes could provide further insights into the vectorial capacity of a species and serve as a novel means of vector control. Insect-specific viruses (ISVs) are only transmitted between insects, and despite some having the ability to restrict the replication of medically important viruses within invertebrates, these viruses have no known effects in vertebrate hosts. To understand the effects that ISVs may have on Cx. pipiens, we exposed larvae to two ISVs, Negev virus (NEGV) and Piura virus (PIUV) through infected cell cultures. We performed mono- and co-infections to gain insight into the viral dynamics within this vector. Exposed larvae were raised into adults and allowed to mate to determine whether either ISV could be transmitted to the offspring. This was followed by fluorescent microscopy of the larvae and adults either mono- or co-infected with these viruses to gain further insight into viral dissemination inside of the vector. Understanding the effects that ISVs may have on Cx. pipiens development, survival, and fertility may provide insight into a possible biocontrol that could potentially reduce some of the burdens of mosquito-borne pathogens.