Which of the following mosquito species is primarily responsible for transmitting West Nile virus?

The species primarily responsible for transmitting West Nile virus is Culex tarsalis. This mosquito is a well-documented vector for the virus, particularly in areas where the virus is prevalent. Culex tarsalis is commonly found in rural and urban environments and tends to breed in standing water, which provides ideal conditions for their population growth. The species has a strong tendency to feed on birds, which are the main reservoir hosts for the West Nile virus, facilitating its maintenance and transmission within the ecosystem.

Understanding the role of Culex tarsalis as a vector highlights the importance of controlling mosquito populations in both urban and rural settings to reduce the risk of West Nile virus transmission to humans and other animals.