a genus or group of closely related mosquitoes that are widespread and thrive in many cities. Some species of these mosquitoes can transmit West Nile virus as well as roundworms that can cause encephalitis...
https://en.wikipedia.org/wiki/CulexHow Many Mosquito Species Are There?
Did you know there are more species of mosquitoes than there are dog breeds? It’s true - there are about 3,500 different mosquito species worldwide, while there are only about 200 different dog breeds. Luckily, not all mosquitoes are known to transmit diseases. Less than 3% of mosquitoes (about 90 species) are known to transmit disease. Additionally, less than 10% of mosquitoes are thought to be able to transmit disease.